Java Technology Blogs

J2EE Interview Questions & Answers

2011-09-18T23:08:00.000-07:00

J2EE Interview Questions & Answers

J2EE is a Java 2 Enterprise Edition. J2EE is an environment for developing and deploying enterprise applications. J2EE specification is defined by Sun Microsystems Inc. The J2EE platform is lies of a set of services, application programming interfaces (APIs), and protocols, which provides the functionality necessary for developing multi-tiered, web-based applications. The J2EE platform is one of the richest platform for the development and deployment of enterprise applications.

Googleforum.info: What is the difference between linker and assembler?

2011-09-18T22:54:00.000-07:00

Googleforum.info: What is the difference between linker and assembler?

Answer1: Here's how it works(Assembler):Most computers come with a specified set of very basic instructions that correspond to the basic machine operations that the computer can perform. For example, a "Load" instruction causes the processor to move a string of bits from a location in the processor's memory to a special holding place called a register. Assuming the processor has at least eight registers, each numbered, the following instruction would move the value (string of bits of a certain length) at memory location 3000 into the holding place called register
Posted On: 2011-09-13 By: Sandeep K Suman

Answer2: An assembler is a program that takes basic computer instructions and converts them into a pattern of bits that the computer's processor can use to perform its basic operations. Some people call these instructions assembler language and others use the term assembly language.
Posted On: 2011-09-13 By: Sandeep K Suman

Answer3: A linker is a program that combines object modules to form an executable program. Many programming languages allow you to write different pieces of code, called modules, separately. This simplifies the programming task because you can break a large program into small, more manageable pieces. Eventually, though, you need to put all the modules together. This is the job of the linker. In addition to combining modules, a linker also replaces symbolic addresses with real addresses. Therefore, you may need to link a program even if it contains only one module.
Posted On: 2011-09-13 By: Sandeep K Suman

Answer4: A program that combines one or more files containing object code into a single file containing executable code. The linker resolves external references among the files, such as function calls. The output of a linker is a machine-code program ready to be loaded into memory and executed.
Posted On: 2011-09-13 By: Sandeep K Suman

Answer5: In computer science, a linker or link editor is a program that takes one or more objects generated by a compiler and combines them into a single executable program.
Posted On: 2011-09-13 By: Sandeep K Suman

MySQL Interview Questions & Answers

2011-09-18T22:48:00.000-07:00

MySQL Interview Questions & Answers

What is the most important feature of Java?
Java is a platform independent language.

What do you mean by platform independence?

Platform independence means that we can write and compile the java code in one platform like (Windows) and we can execute the class in any other supported platform like (Linux, Solaris etc).

Is JVM platform independent?

JVM is not platform independent. It is a platform specific run time implementation provided by the vendor.

What is a JVM?

JVM is Java Virtual Machine which is a run time environment for the compiled java class files.

Difference between JRE/JVM/JDK?

To See in Details Click on this Link:- http://javasks.blogspot.com/2009/01/difference-between-jre-jvm-and-jdk.html

Online free training

2010-03-08T23:56:00.000-08:00

Take a free online training on any technology like java, jsp, servlet, hibernate, php, spring, flex.

for more details pls visit: http://jspservlettutorial.info

Percentile Calculation in C++

2010-01-16T06:31:00.000-08:00

Question: Write a program for the problem: the array of inetegers indicating the marks of the students is given, U have to calculate the percentile of the students aaccording to this rule: the percentile of a student is the %of no of student having marks less then him. For eg: suppose

Student Marks
A 12
B 60
C 80
D 71
E 30
F 45

percentile of C = 5/5 *100 = 100 (out of 5 students, 5 are having marks less then him)

percentile of B = 3/5*100 = 60% (out of 5, 3 have markses less then him)

percentile of A = 0/5*100 = 0%.

Answer:

#include
#include

void main()
{
clrscr();
int a[10],n,i,j;
int percent;
int count;
cout<<"
enter the size of array";
cin>>n;
cout<<"
enter the values";
for(i=0;i<=n-1;i++)
{
cout<<" a["< cin>>a[i];
}

for( i=0;i<=n-1;i++)
{ count=0;
for(j=0;j<=n-1;j++)
{ if(a[i]>a[j])
{
count=count+1;
}
}
percent=(count*100)/(n-1);
cout<<"

the percentile of"<<"a["< }
getch();

}

Gmail: Move Chat To Right Side

2009-11-12T22:00:00.001-08:00

Share

Gmail: Chat is not working in left side? You can move it to the right side.

1. Login to Gmail.

2. Click the Settings link in the upper-right corner.

3. Click the Labs link.

4. Scroll down to where it option right side chat. Click Enable.

5. Scroll to the bottom and click Save Changes.

How to Use Google Adsense Account for More Than One Site or Blog

2009-10-11T06:01:00.000-07:00

1. Log on to your Google Adsense account. There are four tabs at the top of the page. The defaulted one (the one you're on) is "Reports."

2. Click the "Adsense Setup" tab.

3. Choose the type of Adsense ad you'd like to add to your website. Continue through the ad-creating interface as usual.

4. When you reach the page that allows you to add channels, stop. Here, click the "Add New Channel" text link. Name the channel something that you will readily identify as pertaining to this particular site. For instance, if you own abc.com and xyz.com, and this add is for the latter site, name your channel xyz.com.

5. Next time you log in to your account to check your Google Adsense statistics, click on the "Top Channels" text link on the Reports page. This will give you a breakdown of your number of page views, number of clicks, CTR (click through rate), and earnings by channel. This will enable you to determine which site is earning more money for you.

Saigun Technology Pvt. Ltd. Written test paper and interview questions with answers

2009-07-24T00:55:00.000-07:00

Core Java

What is the most important feature of Java?
Java is a platform independent language.
What do you mean by platform independence?
Platform independence means that we can write and compile the java code in one platform like (Windows) and we can execute the class in any other supported platform like (Linux, Solaris etc).
Is JVM platform independent?
JVM is not platform independent. It is a platform specific run time implementation provided by the vendor.
What is a JVM?
JVM is Java Virtual Machine which is a run time environment for the compiled java class files.
Difference between JRE/JVM/JDK? To See in Details Click on this Link:-
JDK (Java Development Kit)

JDK= JDK tools + JRE

JRE = JVM + Java Packages Classes(like util, math, lang, awt,swing etc)+runtime libraries.

JDK contains tools required to develop the Java programs, and JRE to run the programs. The tools include compiler (javac.exe), Java application launcher (java.exe), Appletviewer, etc…

JAVA Compiler converts java code into byte code. and java application launcher opens a JRE, loads the class, and invokes its main method.

If you want to write and compile your own programs, you need JDK. If you just want to run your java programs, JRE is sufficient. JRE is targeted for execution of Java files

You can create a Java file (with the help of Java packages), compile a Java file and run a java file. JDK is mainly targeted for java development.

JRE (Java Runtime Environment)
Java Runtime Environment contains JVM, class libraries, and other supporting files. It does not contain any development tools such as compiler, debugger, etc. Actually JVM runs the program, and it uses the class libraries, and other supporting files provided in JRE. If you want to run any java program, you need to have JRE installed in the system.

JVM(Java Virtual Machine)
The Java Virtual Machine provides a platform-independent way of executing code, programmers can concentrate on writing application, without having to be concerned with how or where it will run.
What is Externalizable? - Externalizable is an Interface that covers Serializable Interface. It sends data into Streams in Compressed Format. It has two methods, that is: writeExternal (ObjectOuput out) and readExternal (ObjectInput in).
What is a pointer and does Java support pointers?
Pointer is a reference deal to a memory location. Improper treating of pointers leads to memory escapes and reliability issues hence Java doesn't support the usage of pointers.
Does Java support multiple inheritance?
Java doesn't support multiple inheritance.
Is Java a pure object oriented language?
Java is not a pure object oriented language because it uses primitive data types.
What is difference between Path and Classpath?
Path and Classpath are operating system level environment variables. Path is used define where the system can find the executables (.exe) files and Classpath is used to specify the location .class files.
Can there be an abstract class with no abstract methods in it? - Yes
1. Can an Interface be final? - No
What are local variables?
Local variables are those which are declared within a block of code like methods. Local variables should be initialized before accessing them.
Can an Interface have an inner class? - Yes.
public interface xyz{
static int i=0;
void ss();

class abc{
abc(){
int j;
System.out.println("In side the interface");
};

public static void main(String abc[]){
System.out.println("Interface is in");
}
}
}
Can we define private and protected modifiers for variables in interfaces? - No
What modifiers are allowed for methods in an Interface? - Only public and abstract modifiers are allowed for methods in interfaces.
What is a local, member and a class variable? - Which variable declared within a method that is called “local” variables, which variable declared within the class (not within any methods) are called “member” variables (global variables) and which variables declared within the class (not within any methods and are defined as “static”) are called class variables.
What are the different identifier states of a Thread? - The different identifiers of a Thread are: R - Running or runnable thread, S - Suspended thread, CW - Thread waiting on a condition variable, MW - Thread waiting on a monitor lock, MS - Thread suspended waiting on a monitor lock
What are some alternatives to inheritance? - Delegation is an alternative to inheritance. Delegation means that you include an instance of another class as an instance variable, and forward messages to the instance. It is often better than inheritance because it forces you to think about each message you forward, because the instance is of a known class, rather than a new class, and because it doesn’t force you to accept all the methods of the super class: you can provide only the methods that really make sense. On the other hand, it makes you write more code, and it is more difficult to re-use (because it is not a subclass).
What is instance variables?
Instance variables are those variable which is defined at the class level. Instance variables need not be initialized before using them as they are automatically initialized to their default values.
What is constant variable in Java?
The constant variable should be declared as static and final. So only one copy of the variable exists for all instances of the class and the value can't be changed.
Should a main method be mandatory declared in all java classes?
No it is not required. main method should be defined only if the source class is a java application.
What is the return type of the main method?
Main method doesn't return anything therefore it declared void.
Why is the main method declared static?
main method is called by the JVM yet before the instantiation of the class hence it is declared as static.
What is the argument of main method?
The main method accepts an array type of String object as an argument.
Can main method be overloaded?
Yes. You can have any number of main methods with different method signature and implementation in the class.
Can a main method be declared final?
Yes. Any inheriting class will not be able to have it's own default main method.
Why isn’t there operator overloading? - Because C++ has proven by example that operator overloading makes code almost impossible to maintain. In fact there very nearly wasn’t even method overloading in Java, but it was thought that this was too useful for some very basic methods like print(). Note that some of the classes like DataOutputStream have unoverloaded methods like writeInt() and writeByte().
How do I convert a numeric IP address like 192.168.10.204 into a hostname like javasks.blogspot.com?
String hostname = InetAddress.getByName("192.168.10.204").getHostName();
Why do threads block on I/O? - Threads block on I/O (that is enters in the waiting state) so that other threads may execute while the I/O operation is performed.
What is synchronization and why is it important? - With respect to multithreading, synchronization is the capability to control the access of multiple threads to shared resources. Without synchronization, it is possible for one thread to modify a shared object while another thread is in the process of using or updating that object’s value. This often leads to significant errors.
Is null a keyword? - No, The null value is not a keyword.
How many bits are used to represent Unicode, ASCII, UTF-16, and UTF-8 characters? - Unicode requires 16 bits and ASCII require 7 bits. while the ASCII character set uses only 7 bits, it is usually represented as 8 bits. UTF-8 represents characters using 8, 16, and 18 bit patterns. UTF-16 uses 16-bit and larger bit patterns.
What are wrapped classes? - Wrapped classes are classes that allow primitive types to be accessed as objects.
What is a native method? - A native method is a method that is implemented in a language other than Java.
What is the catch or declare rule for method declarations? - If a checked exception may be thrown within the body of a method, the method must either catch the exception or declare it in its throws clause.
What is the range of the char type? - The range of the char type is 0 to 2^16 - 1.
------------------------------------------------------------------------------------------------------------------------------

JSP

What is JSP and why it used in java?
JSP is a framework which is the part of MVC model, it stand for view which show on the front end of the application, it is a normally HTML pages with Java code pieces embedded in them. JSP pages are saved to *.jsp files. A JSP compiler is used in the background to generate a Servlet from the JSP page.
Differentiate between and response.sendRedirect(url),?.
The element forwards the request object holding the client request information from one JSP file to another file.
sendRedirect sends HTTP temporary redirect response to the browser, and browser creates a new request to go the redirected page.
Differentiate between custom JSP tags and beans?
Custom JSP tag is a tag you defined. To use custom JSP tags, you need to define three things:
1. The tag handler class that specifies the tag\'s behavior
2. The tag library descriptor file that maps the XML element names
3. the JSP file that uses the tag library
JavaBeans are Java utility classes you defined.
to declare a bean and use
to set value of the bean class and use
to get value of the bean class.
What are comments in JSP?
1: <%-- JSP Comment --%>
2:
3: <% // Java comments %>
4: <% /* Java comments*/ %>
What is JSP technology?
JSP is a standard Java extension that is defined on top of the servlet Extensions. The goal of JSP is the simplified creation and management of dynamic Web pages.
What is JSP page?
A text-based document that contains two types of text: static template data, which can be showed in any text-based format such as HTML, SVG, WML, and XML, and JSP elements, which construct dynamic content.
Describe implicit objects?
Implicit objects are objects that are created by the web container and contain information related to a particular request, page, or application. They are:
* request
* response
* pageContext
* session
* application
* out
* config
* page
* exception
How many JSP scripting elements and what are they?
There are three scripting language elements:
*declarations
*scriptlets
*expressions
Why are JSP pages the preferred API for creating a web-based client program?
Because no plug-ins or security policy files are needed on the client systems(applet does).
Differentiate between and <%@ include file = ... >?.
: This is like a function call from one jsp to another jsp.
<%@ include file = ... >: . In this case in the included file changes, the changed content will not included in the output. This approach is used when the code from one jsp file required to include in multiple jsp files.
Is JSP is extensible technology?
YES. JSP technology is extensible through the development of custom actions, or tags, which are encapsulated in tag libraries.
Can we use the constructor, instead of init(), to initialize servlet?
Yes , of course we can use the constructor instead of init(). The original reason for init() was that ancient versions of Java couldn’t dynamically invoke constructors with arguments, so there was no way to give the constructur a ServletConfig.
How can a servlet refresh automatically if some new data has entered the database?
You can apply a client-side Refresh or Server Push.
The code in a finally clause will never fail to execute, right?
Using System.exit(1); in try block will not allow finally code to execute.
How many messaging models do JMS provide for and what are they?
JMS provide for two messaging models,
1:publish-and-subscribe and
2:point-to-point queuing.
What type of information is needed to create a TCP Socket?
The Local Systems IP Address and Port Number. And the Remote System’s IPAddress and Port Number.
What Class.forName will do while loading drivers?
It is used to create an instance of a driver and register it with the DriverManager.
How to Retrieve Warnings?
A warning can be reported on a Connection object, a Statement object (including PreparedStatement and CallableStatement objects), or a ResultSet object. Each of these classes has a getWarnings method, which you must invoke in order to see the first warning reported on the calling object.
How many types of JSP scripting elements are there and what are they?
There are three scripting language elements:
declarations, scriptlets and expressions.
In the Servlet 2.4 specification SingleThreadModel has been deprecated, why?
Because it is not practical to have such model. Whether you set isThreadSafe to true or false, you should take care of concurrent client requests to the JSP page by synchronizing access to any shared objects defined at the page level.
What are stored procedures? How is it useful?
"A stored procedure is a set of statements/commands which reside in the database". The biggest advantage is of course speed. Also certain kind of data manipulations are not achieved in SQL. Stored procs provide a mechanism to do these manipulations. Stored procs are also useful when you want to do Batch updates/exports/houseKeeping kind of stuff on the database.
How do I include static files within a JSP page?
Static resources should always be admitted using the JSP include directive. This way, the inclusion is performed just once during the translation phase. Note that you should always supply a relative URL for the file attribute. Although you can also include static resources using the action, this is not advisable as the inclusion is then performed for each and every request.
Why does JComponent have add() and remove() methods but Component does not?
because JComponent is a subclass of Container, and can contain other components and jcomponents.
How can I implement a thread-safe JSP page?
This is done by adding the directive <%@ page isThreadSafe="false" % > within your JSP page.
If the browser has disabled cookies. How can we enable session tracking for JSP pages ?
We know that session tracking uses cookies by default to associate a session identifier with a unique user. If the browser does not support cookies, or if cookies are disabled, you can still enable session tracking using URL rewriting. URL rewriting essentially includes the session ID within the link itself as a name/value pair.
What is a output comment?
The JSP engine handles an output comment as uninterrupted HTML text, returning the comment in the HTML output sent to the client. You can see the comment by viewing the page source from your Web browser.
What is a Hidden Comment?
A comments that documents the JSP page but is not sent to the client. The JSP engine ignores a hidden comment, and does not process any code within hidden comment tags.
JSP Syntax
<%-- comment --%>
What is a Declaration
A declaration declares one or more variables or methods for use later in the JSP source file. A declaration must contain at least one complete declarative statement. You can declare any number of variables or methods within one declaration tag, as long as they are separated by semicolons. <%! declarations %>
<%! int i = 0; %> <%! int a, b, c; %>
What is a Scriptlet
A scriptlet can contain any number of language statements, variable or method declarations, or expressions that are valid in the page scripting language.Within scriptlet tags, you can
1.Declare variables or methods
2.Write expressions valid in the page scripting language
3.Use any of the JSP implicit objects
What are implicit objects? List them?
Certain objects that are available for the use in JSP documents without being declared first. These objects are parsed by the JSP engine and inserted into the generated servlet.
Difference between forward and sendRedirect?
When a sendRedirtect method is invoked, it causes the web container to return to the browser indicating that a new URL should be requested. Because the browser issues a completly new request any object that are stored as request attributes before the redirect occurs will be lost. This extra round trip a redirect is slower than forward.
What are the different scope values for the ?
The four different scope values for are
1. page
2. request
3.session
4.application
Explain the life-cycle mehtods in JSP?
The JspPage interface declares only two mehtods - jspInit() and jspDestroy() that must be implemented by all JSP pages regardless of the client-server protocol. However the JSP specification has provided the HttpJspPage interfaec specifically for the JSp pages serving HTTP requests. This interface declares one method _jspService(). The jspInit()- The container calls the jspInit() to initialize the servlet instance.It is called before any other method, and is called only once for a servlet instance. The jspservice()- The container calls the _jspservice() for each request, passing it the request and the response objects. The jspDestroy()- The container calls this when it decides take the instance out of service. It is the last method called n the servlet instance.
---------------------------------------------------------------------------------------------------------------------------------

JDBC
How can you establish connection?
To establish a connection you need to have the appropriate driver connect to the DBMS.
The following line of code we use:
String url = “jdbc:odbc:Fred”;
Connection con = DriverManager.getConnection(url, “Fernanda”, “J8?);
Define different types of Statements?
There are three types of statements
• Regular statement
• prepared statement
• callable statement
What are the components of JDBC?
The two major components of JDBC are Connection Pooling and Data Sources.
Define metadata?
Metadata is data about data.
In JDBC, there are two types
1. Describing information about the Result set object. i
2. describes about the database connection
Differentiate between local and global transaction?
A transaction is atomic unit of Work.
Transactions can be divided into two categories.
1.Local Transactions: These transactions are confined to the objects which reside inside one particular JVM.
2.Global Transactions:These transactions may encapsulate objects which are distributed on various JVM's.
What is the technique to call a Stored Procedure from JDBC?
The first step is to create a CallableStatement object. As with as a Statement an and PreparedStatement objects, this is done with an open Connection object.
E.g.CallableStatement cs = con.prepareCall("{call SHOW_SUPPLIERS}");
ResultSet rs = cs.executeQuery();
Why JDBC objects generate SQLWarnings?
Connections, Statements and ResultSets all have a getWarnings method that allows retrival.The prior ResultSet warnings are cleared on each new read and prior Statement warnings are cleared with each new execution.
What are the components of JDBC?
The two major components of JDBC is One implementation interface for the database manufacturers, the other implementation interface for application and applet writers.
How web server is connected with appliction server?
All the application server requires to the information about the installed web server's port and name, through these entries it creates a connector and stored. This connector is used to communicate with Application server.
Differentiate between Rowset and Resultset?
RowSets are a part of JDBC 2.0 API. Essentially a row set is a JavaBean that contains database data. The implementation is store the data offline, or it can simply wrap a connection to make a result set look like a JavaBean. You could even use a row set to access data communicating over HTTP to a servlet, which provides the data for the bean.
How can we insert images into a Mysql database?
This code is snip shows the basics:
File file = new File(fPICTURE);
FileInputStream fis = new FileInputStream(file);
PreparedStatement ps =
ConrsIn.prepareStatement("insert into dbPICTURE values (?,?)");
ps.setString(1,file.getName());
ps.setBinaryStream(2,fis,(int)file.length());
ps.close();
fis.close();
Define advantage of using a PreparedStatement?
For SQL statements that are executed repeatedly, using a PreparedStatement object would almost always be s faster than using a Statement object. This is because creating a PreparedStatement object by explicitly giving the SQL statement causes the statement to be precompiled within the database immediately.
Typically, PreparedStatement objects are used for the SQL statements that take parameters.
How does the JDBC work?
The Java Database Connectivity (JDBC) is used to whenever a Java application should communicate with a relational database for which a JDBC driver exists.
Main JDBC classes:
• DriverManager. Manages a list of database drivers.
• Driver. The database communications link, handling all communication with the database.
• Connection. Interface with all the methods for contacting a database
• Statement. Encapsulates an SQL statement which is passed to the database to be parsed, compiled, planned and executed.
• ResultSet. The answer/result from a statement. A ResultSet is a fancy 2D list which encapsulates all outgoing results from a given SQL query.
--------------------------------------------------------------------------------------------------------------------------

MySQL
What is Primary Key?
A primary key is a single column or multiple columns is defined to have unique values that can be used as a row identifications.
What is Transaction?
MySQL server is introduced the transaction concept to allow users to group one or more SQL statements into a single transaction, so that the effects of all the SQL statements in a transaction can be either all committed or all rolled back. A transaction is a logical unit of work requested by a user to be applied to the database objects.
What are the indexes?
An index is an internal structure which is provided quick access to rows of a table based on the values of more than one columns.
What is a foreign key?
A foreign key is a constraint associates one or more columns in a table with an identical set of columns on which a primary key has been defined in another table. A foreign key may refer to the primary key of another table or same table.
What is the advantages of MySQL against oracle?
MySQL are many advantages in comparison to Oracle.
• MySQL is Open a source, which can be available any time
• MySQL has no cost of development purpose.
• MySQL has most of features , which oracle provides
• MySQL day by day updating with the new facilities.
• Good for small application.
• Easy to learn and to become master.
• MySQL has a good power these days.
-------------------------------------------------------------------------------------------------------------------------------

Servlet
Question: What are the lifecycle methods of Servlet?
Answer: The interface javax.servlet.Servlet, defines the three life-cycle methods. These are:
public void init(ServletConfig config) throws ServletException
public void service( ServletRequest req, ServletResponse res) throws ServletException, IOException
public void destroy()
The container manages the lifecycle of the Servlet. When a new request come to a Servlet, the container performs the following steps.
1. If an instance of the servlet does not exist, the web container
* Loads the servlet class.
* Creates an instance of the servlet class.
* Initializes the servlet instance by calling the init method. Initialization is covered in Initializing a Servlet.
2. The container invokes the service method, passing request and response objects.
3. To remove the servlet, container finalizes the servlet by calling the servlet's destroy method.
Question: What are the type of protocols supported by HttpServlet?
Answer: It extends the GenericServlet base class and provides an framework for handling the HTTP protocol. So, HttpServlet only supports HTTP and HTTPS protocol.
Question: What are the directory Structure of Web Application?
Answer: Web component follows the standard directory structure defined in the J2EE specification.
Directory Structure of Web Component
/
index.htm, JSP, Images etc..
Web-inf

web.xml
classes

servlet classes
lib

jar files
Question: What is ServletContext?
Answer: ServletContext is an Interface that defines a set of methods that a servlet uses to communicate with its servlet container, for example, to get the MIME type of a file, dispatch requests, or write to a log file. There is one context per "web application" per Java Virtual Machine. (A "web application" is a collection of servlets and content installed under a specific subset of the server's URL namespace such as /catalog and possibly installed via a .war file.)
Question: What is meant by Pre-initialization of Servlet?
Answer: When servlet container is loaded, all the servlets defined in the web.xml file does not initialized by default. But the container receives the request it loads the servlet. But in some cases if you want your servlet to be initialized when context is loaded, you have to use a concept called pre-initialization of Servlet. In case of Pre-initialization, the servlet is loaded when context is loaded. You can specify 1
in between the tag.
Question: What mechanisms are used by a Servlet Container to maintain session information?
Answer: Servlet Container uses Cookies, URL rewriting, and HTTPS protocol information to maintain the session.
Question: What do you understand by servlet mapping?
Answer: Servlet mapping defines an association between a URL pattern and a servlet. You can use one servlet to process a number of url pattern (request pattern). For example in case of Struts *.do url patterns are processed by Struts Controller Servlet.
Question: What must be implemented by all Servlets?
Answer: The Servlet Interface must be implemented by all servlets.
Question: What are the differences between Servlet and Applet?
Answer: Servlets are server side components that runs on the Servlet container. Applets are client side components and runs on the web browsers. Servlets have no GUI interface.
Question: What are the uses of Servlets?
Answer: * Servlets are used to process the client request.
* A Servlet can handle multiple request concurrently and be used to develop high performance system
* A Servlet can be used to load balance among serveral servers, as Servlet can easily forward request.
Question: What are the objects that are received when a servlets accepts call from client?
Answer: The objects are ServeltRequest and ServletResponse . The ServeltRequest encapsulates the communication from the client to the
server. While ServletResponse encapsulates the communication from the Servlet back to the client.

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2009-07-04T04:56:00.000-07:00

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Bank Clerical Exams Model Test Papers, 2004

2009-06-17T00:48:00.000-07:00

Test I & II : Reasoning ability and Numerical Aptitude

1. Suresh is taller than Prabhu but shorter than Ram, Prabhu
is as tall as Neeraj but taller than Nilesh. Which of the
following statements is definitely true for Neeraj?
(a) Neeraj is shorter than Nilesh
(b) Neeraj is the tallest
(c) Neeraj is the shortest
(d) Neeraj is taller than Nilesh
(e) None of these
Ans: ( d ) Neeraj is taller than Nilesh

2. How many such pairs of letters are there in the word
STAINLESS each of which has as many letters between them in
the word as they have in the English alphabet, in the same
sequence?
(a) Two
(b) Three
(c) Four
(d) Five
(e) None of these
Ans: ( e ) None of these

3. What will come in place of the question mark (?) in the
following sequence?
ARRANGEMENTS, RRANGEMENT, RANGEMEN, ?, NGEM
(a) RANGEME
(b) ANGEME
(c) ANGEMENT
(d) NGEMEN
(e) None of these
Ans: ( b ) ANGEME

4. Four of the following five are alike in a certain way and
so form a group. Which is the one that does not belong to
that group?
(a) Baking
(b) Steaming
(c) Cooking
(d) Frying
(e) Boiling
Ans: ( c ) Cooking

5. Four of the following five are alike in a certain way and
so form a group which is the one that does not belong to
that group?
(a) Radish
(b) Orange
(c) Pear
(d) Mango
(e) Apple
Ans: ( a ) Radish

6. Four of the following five are alike in a certain way and
so form a group. Which is the one that does not belong to
that group?
(a) Earth
(b) Moon
(c) Saturn
(d) Pluto
(e) Venus
Ans: ( b ) Moon

7. If water is called food, food is called drink, drink is
called blue, blue is called red, red is called white and
white is called brown, then what is the colour of ?blood? ?
(a) Blue
(b) Red
(c) Brown
(d) White
(e) Drink
Ans: ( d ) White

8. In a certain code language, the word ENQUIRY is written
as YRIUQNE. How will the word REQUIRE be written in the
code language ?
(a) QERUERI
(b) REQUERI
(c) ERIUQER
(d) IREUQER
(e) None of these
Ans: ( c ) ERIUQER

9. In a certain code language DESERT is written RTSEDE. How
will the word FAULTS the written in that code language?
(a) TSULFA
(b) AFLUST
(c) LUAFST
(d) UAFSTL
(e) None of these
Ans: ( a ) TSULFA

10. How many meaningful English word can be formed by using
the second, the fifth, the seventh and the tenth letters of
the word APPROPRIATION, each only once, but in different
sequence ?
(a) One
(b) Two
(c) Three
(d) None of these
(e) More than three
Ans: ( a ) One

Directions (Qs. 11?15) :What will come in place of the question mark (?) in the following questions?

11. 7589 ? ? = 3434
(a) 3721
(b) 4155
(c) 3246
(d) 11023
(e) None of these
Ans: ( b ) 4155

12. 300 + (10)2 x 2 = ?
(a) 450
(b) 800
(c) 500
(d) 550
(e) None of these
Ans: ( c ) 500

13. 12.05 x 5.4 ÷ 0.6 = ?
(a) 105.55
(b) 108.45
(c) 118.45
(d) 118.55
(e) None of these
Ans: ( b ) 108.45

14. 2435 ÷ 24 = 24?
(a) 2.5
(b) 3.5
(c) 2
(d) 3
(e) None of these
Ans: ( a ) 2.5

15. 78 x 14 + 7645 ? ? = 8247
(a) 580
(b) 590
(c) 490
(d) 480
(e) None of these
Ans: ( c ) 490

Directions (Qs. 16?17) :
I. ?P + Q? means P is the brother of Q
II. ?P x Q? means P is the mother of Q
III. ?P ÷ Q? means P is the sister of Q
IV. ?P ? Q? means Q is the father of P

16. Which of the following represents ?B is the material
uncle of C??
(a) B + A x C
(b) B x C + A
(c) B ÷ C + A
(d) B x A + c
(e) None of these
Ans: ( a ) B + A x C

17. Which of the following statements is not necessary to
answer the above question?
(a) Only I and II
(b) Only III
(c) Only III and IV
(d) Either II or III
(e) All are necessary
Ans: ( c ) Only III and IV

18. Pointing towards a woman a boy said, ?she is the only
daughter of my mother?s brother?s only brother-in-law?. How
the woman is related to the boy?
(a) Mother
(b) Aunt
(c) Sister-in-law
(d) Sister
(e) None of these
Ans: ( d ) Sister

19. Four of the following five are alike in a certain way
and hence form a group. Which one of the following does not
belong to that group?
(a) 63
(b) 64
(c) 39
(d) 48
(e) 79
Ans: ( e ) 79

20. Ina certain code language DOWNBEAT is written as
TABEWNDO. How will the word PROSPECT be written in that
code language?
(a) RPSOEPTC
(b) TCPEOSPR
(c) ORPSPTCE
(d) TCPREPOS
(e) None of these
Ans: ( b ) TCPEOSPR

Directions (Qs. 21?26) : What will come in place of the
question mark (?) in the following questions?

21. 37.5 ÷ (27)1.5 x 92 = 3?
(a) 5
(b) 4.5
(c) 7
(d) 6.5
(e) None of these
Ans: ( c ) 7

22. 28% of 450 + 45% of 280 = ?
(a) 126
(b) 252
(c) 324
(d) 212
(e) None of these
Ans: ( b ) 252

23. 1027.05 ? 314.005 + 112.25 = ?
(a) 825.395
(b) 825.095
(c) 825.305
(d) 825.295
(e) None of these
Ans: ( d ) 825.295

24. (103.7 x 101.3)2 = 10?
(a) 6
(b) 7
(c) 10
(d) 3
(e) None of these
Ans: ( c ) 10

25. 40.83 x 1.02 x 1.2 = ?
(a) 49.97592
(b) 41.64660
(c) 58.7952
(d) 42.479532
(e) None of these
Ans: ( a ) 49.97592

26. 3978 + 112 x 2 = ? ÷ 2
(a) 8180
(b) 2101
(c) 4090
(d) 8404
(e) None of these
Ans: ( d ) 8404

27. Four of the following five are alike in a certain way
and hence form a group. Which one of the following does not
belong to that group?
(a) 21
(b) 35
(c) 49
(d) 63
(e) 56
Ans: ( c ) 49

28. P is heavier than Q but lighter than R. Q is heavier
than T. S is heavier than P but lighter than V. Who among
them is the lightest?
(a) V
(b) S
(c) T
(d) R
(e) None of these
Ans: ( c ) T

29. In a certain code language TRANSPORT is written as
RTASNPORT. How will the word GATEHOUSE be written in that
code language ?
(a) ETGAHOESU
(b) ETAGHESUO
(c) AGTHEOUSE
(d) AGETHUOES
(e) None of these
Ans: ( c ) AGTHEOUSE

30. In a certain code language ?si re ga? MEANS ?Shyam is
smart? and ?pa si ga? means? Animesh is smart?. What is the
code for ?smart? in that code language?
(a) si
(b) re
(c) ga
(d) pa
(e) None of these
Ans: ( e ) None of these

Directions (Qs. 31?34) : What will come in place of the
question-mark (?) in the following questions ?

31. 12.05 x 5.4 ÷ 0.3 = ?
(a) 108.55
(b) 216.90
(c) 118.45
(d) 118.55
(e) None of these
Ans: ( b ) 216.90

32. 99 ÷ 11 + 7 x 16 = (?)2
(a) 11
(b) 121
(c) 12
(d) 144
(e) None of these
Ans: ( a ) 11

33. 8400 ÷ 120 x 15 + 150 = ?
(a) 1050
(b) 1200
(c) 1100
(d) 1514
(e) None of these
Ans: ( b ) 1200

34. 45% of 1500 + 35% of 1700 = ?% of 3175
(a) 40
(b) 55
(c) 45
(d) 35
(e) None of these
Ans: ( a ) 40

Directions (Qs. 35?39) : Study the following information
carefully and answer the questions given below:
The number 0 to 9 are coded in the following manner
considering the exception given below:

3 6 9 7 0 2 8 1 5 4
H P V S G D J K M R
.
Exception 1:If a number starts and ends with non-zero odd
number then the first and the last digits should be coded as
X and Z.
Exception 2:If a number starts and ends with non-zero even
number then the first and the last digits should be coded as
A and B respectively.

35. What is the code for 5 2 1 8 6 3 ?
(a) MDKJPH
(b) ZDKJPX
(c) XDKJPZ
(d) ADKJPB
(e) None of these
Ans: ( c ) XDKJPZ

36. What is the code for 492310 ?
(a) RVDHKG
(b) AVDHKB
(c) VRDKHG
(d) BVDHKA
(e) None of these
Ans: ( a ) RVDHKG

37. Which of the following numbers is represented by ASGHKB?
I. 670312 II. 470313 III. 270318
(a) Only I and III
(b) Only I and II
(c) Only Ii and III
(d) Only I
(e) Only III
Ans: ( a ) Only I and III

38. What is the code for 3186452 ?
(a) HKJDMRP
(b) KHPJMRD
(c) DMRPHKJ
(d) HKJPRMD
(e) None of these
Ans: ( d ) HKJPRMD

39. Which of the following numbers is represented by DPJRSV ?
(a) 628794
(b) 268479
(c) 246793
(d) 168359
(e) None of these
Ans: ( b ) 268479

40. Animesh and Anand together got a profit of Rs. 9,600 and
they distributed between themselves in the ratio of 5 : 7.
What is the share of Animesh?
(a) Rs. 4,000
(b) Rs. 5,600
(c) Rs. 4,800
(d) Rs. 5,200
(e) None of these
Ans: ( a ) Rs. 4,000

41. A man bought some fruits at the rate of 16 for Rs. 24
and sold them at the rate of 8 for Rs. 18. What is the
profit per cent?
(a) 50%
(b) 60%
(c) 40%
(d) 25%
(e) None of these
Ans: ( a ) 50%

42. A cow is tethered in the middle of a field with a 14
feet long rope. If the cow grazes 100 sq feet per day
approximately. What time will be taken by the cow to graze
the grazeable area of the field?
(a) 2 days
(b) 18 days
(c) 24 days
(d) 6 days
(e) None of these
Ans: ( d ) 6 days

43. 7/8 of 3/7 of a number is equal to 25% of 45% of
another number. What is the ratio of the first and the
second numbers respectively?
(a) 3 : 7
(b) 9: 10
(c) 3 : 10
(d) 3 : 2
(e) None of these
Ans: ( c ) 3 : 10

44. Mr. Rahul spends 30% of his monthly salary on domestic
expenses. He spends respectively 20% and 10% of the
remaining salary on education of children and conveyance.
Of the remaining amounts now he spends respectively 20% and
30% on entertainment and maintenance of house. He saves Rs.
5512.50. what is the monthly salary of Mr. Rahul?
(a) Rs. 22,500
(b) Rs. 20,000
(c) Rs. 25,000
(d) Rs. 24,500
(e) None of these
Ans: ( a ) Rs. 22,500

45. The ratio of the present ages of Suman and Renu is 5 : 7
respectively. Four years hence the ratio will become 3 : 4
respectively. What is the present age of Renu in years?
(a) 28
(b) 24
(c) 20
(d) 21
(e) None of these
Ans: ( a ) 28

46. If instead of multiplying a number by 7 the number was
divided by 7. What should be the percentage error?
(a) 100%
(b) 96.8%
(c) 92.70%
(d) 97.9%
(e) None of these
Ans: ( d ) 97.9%

47. A car covers a certain distance taking 7 hours in
forward journey. During the return journey, speed was
increased by 12 kmph and it takes 5 hours. What is total
distance covered?
(a) 210 km
(b) 70 km
(c) 440 km
(d) 220 km
(e) None of these
Ans: ( a ) 210 km

48. The LCM of two numbers is 2079 and their HCF is 27. If
one of the numbers is 189, find the other number.
(a) 248
(b) 128
(c) 297
(d) 336
(e) None of these
Ans: ( c ) 297

49. The average between a two digit number and the number
obtained by interchanging the digits is 9. What is the
difference between the two digits of the number?
(a) 8
(b) 2
(c) 5
(d) Cannot be determined
(e) None of these
Ans: ( d ) Cannot be determined

50. A circle and a rectangle have the same perimeter. The
sides of the rectangle are 18 cm and 26 cm. What will be
the area of the circle?
(a) 88 cm2
(b) 1250 cm2
(c) 154 cm2
(d) 128 cm2
(e) None of these
Ans: ( e ) None of these

51. The difference between a number and its three-fifth is
50. What is the number?
(a) 75
(b) 100
(c) 125
(d) 80
(e) None of these
Ans: ( c ) 125

52. Some persons decide to raise Rs. 3 lakhs by equal
contribution from each of them. If they contributed Rs. 50
extra each, the contribution increased to Rs. 3.25 lakhs.
How many persons were there ?
(a) 400
(b) 500
(c) 600
(d) 700
(e) None of these
Ans: ( b ) 500

53. A sample of milk contains 5% water. What quantity of
pure milk should be added to 10 litres of milk to reduce the
water content to 2%?
(a) 5 litres
(b) 7 litres
(c) 15 litres
(d) 12 litres
(e) None of these
Ans: ( c ) 15 litres

54. The difference between the compound interest and the
simple interest on a certain sum of money at 5% per annum
for 2 years is Rs. 1.50. Find the sum.
(a) Rs. 800
(b) Rs. 1200
(c) Rs. 400
(d) Rs. 600
(e) None of these
Ans: ( d ) Rs. 600

55. A, B and C contract a work for Rs. 550. Together A and
B are supposed to do 7/11th of the work. How much does C get?
(a) Rs. 270
(b) Rs. 200
(c) Rs. 310
(d) Rs. 175
(e) None of these
Ans: ( b ) Rs. 200

Directions (Qs. 56?60) : Study the following information
carefully and answer the questions given below:

There is a five storey building including the ground floor
and each floor has only one flat. All these flats have been
occupied by the five Bank Probationary Officers. Each
officer owns a different car. The cars are : Indica, Ikon,
Indigo, Elentra and Santro. The five officers?A, B, X, Y
and Z ? are employed in the different banks, viz., State
Bank of India (SBI), Punjab National Bank (PNB), UCO Bank,
ICICI Bank and HDFC Bank but not necessarily in the same
order. Mr. X works in HDFC Bank and lives on the ground
floor. The officer who lives on fourth (top) floor does not
own Elentra or Santro. Mr. B works in PNB and owns Elentra
car. The officer who works in UCO Bank and lives on second
floor owns Indica car. Mr. Y lives on third floor and owns
Indigo. Mr. Z works in ICICI Bank and Mr. Y works in State
Bank of India.

56. Who among the following does own Santro car ?
(a) A
(b) B
(c) X
(d) Cannot be determined
(e) None of these
Ans: ( c ) X

57. Who lives on the second floor ?
(a) X
(b) Y
(c) Z
(d) A
(e) None of these
Ans: ( d ) A

58. On which floor does B live ?
(a) First
(b) Second
(c) Fourth
(d) Cannot be determined
(e) None of these
Ans: ( a ) First

59. Who among the following owns Indica car ?
(a) X
(b) A
(c) Y
(d) B
(e) None of these
Ans: ( b ) A

60. Which of the following combinations of the officer and
car is correct ?
(a) Mr. X : Elentra
(b) Mr. Y : Ikon
(c) Mr. A : Santro
(d) Mr. Z : Ikon
(e) None of these
Ans: ( d ) Mr. Z : Ikon

61. For which of the following values of x the inequality x
(x + 3) <> 2, x < -5 (b) -3 <> 5
(e) None of these
Ans: ( b ) -3 < x < 0

62. There is a leak in the bottom of a cistern. When the
cistern is thoroughly repaired, it would be filled in 3 ½
hours. It now takes half an hour longer. If the cistern is
full, how long will the leak take to empty the cistern?
(a) 24 hours
(b) 28 hours
(c) 21 hours
(d) 27 hours
(e) None of these
Ans: ( a ) 24 hours

63. If the diagonals of a rhombus are 8 cm and 10 cm
respectively what will be the area of the rhombus?
(a) 35 sq cm
(b) 40 sq cm
(c) 30 sq cm
(d) 20 sq cm
(e) None of these
Ans: ( b ) 40 sq cm

64. Some toys were distributed equally among 18 children in
such a way that the number of toys each child gets is equal
to the total number of children and after distribution 6
toys are left out. What was the total number of toys?
(a) 324
(b) 330
(c) 336
(d) 320
(e) None of these
Ans: ( b ) 330

65. A shopkeeper allows 10% discount on the price of an
article and sells it for Rs. 7,600. What is the market
price of the article ?
(a) Rs. 8,250
(b) Rs. 8,500
(c) Rs. 8,540
(d) Rs. 8,415
(e) None of these
Ans: ( e ) None of these

Directions (Qs. 66?70) : Below in each question five words
are given. Which of them will come in the middle place if
all of them are arranged alphabetically? Serial number of
that word is the answer.

66. (a) Encounter
(b) Enormous
(c) Engineer
(d) Enlarge
(e) Encroach
Ans: ( c ) Engineer

67. (a) Network
(b) Nepotism
(c) Neutral
(d) Neighbour
(e) Nervous
Ans: ( e ) Nervous

68. (a) Granular
(b) Gratuity
(c) Gravitate
(d) Greatness
(e) Grateful
Ans: ( b ) Gratuity

69. (a) Residential
(b) Reputation
(c) Resistant
(d) Residence
(e) Reschedule
Ans: ( d ) Residence

70. (a) Bracelet
(b) Boutique
(c) Bourgeois
(d) Brackish
(e) Bramble
Ans: ( a ) Bracelet

Directions (Qs. 71?75) :The number group in each question
is to be codified in the following codes :

Number 3 8 7 0 1 9 6 4 2 5
Codes N L D M H B V R G P
.
You have to find out which of the answers (A), (B), (C) and
(D) has the correct coded form of the given number group.
If none of the coded form is correct, mark (E) as the answer.

71. 6182734
(a) HBGPLDM
(b) VBLGRNH
(c) VHLGDNR
(d) BHNDGHR
(e) None of these
Ans: ( c ) VHLGDNR

72. 349805
(a) NRBLMP
(b) BRNLPM
(c) LRDGMP
(d) PMLHBR
(e) None of these
Ans: ( a ) NRBLMP

73. 57920642
(a) DPBGMVRH
(b) PDBRLNGH
(c) MVRGHLDP
(d) PDBGMVRG
(e) None of these
Ans: ( d ) PDBGMVRG

74. 7561024
(a) DPVGMRH
(b) DPVHMGR
(c) HMRLDVP
(d) VHDPGRL
(e) None of these
Ans: ( b ) DPVHMGR

75. 48236017
(a) RLGDLMHV
(b) BNDPGMRH
(c) VHMGDMRL
(d) HNPGBMHV
(e) None of these
Ans: ( e ) None of these

Directions (Qs. 76?80) : The news item given in each
question below is to be classified into one of the following
five areas.
(a) Political and Social, (b) sports and Culture, (c)
Science and Health
(d) Economics and Commerce, and (e) Miscellaneous

76. International Film Festival of India was organized in
Chennai recently.
Ans: ( b ) sports and Culture

77. India will host 2010 Commonwealth Games
Ans: ( b ) sports and Culture

78. Sustained efforts are needed to secure the release of
hotages.
Ans: ( e ) Miscellaneous

79. India and Japan are considering to have dialogue on
defence issue.
Ans: ( a ) Political and Social

80. New vaccine MMR has been developed for children.
Ans: ( c ) Science and Health

TEST ?III :: ENGLISH LANGUAGE

Directions (Qs. 81?90) :In the following passage there are
blanks, each of which has been numbered. These numbers are
printed below the passage and against each, five words are
suggested, one of which fills the blank appropriately. Find
out the appropriate word in each case.

Fourteen centuries ago when the world was much younger,
the ruler of all India, Rajah Balhait, was ??..(151) about
his people. A new game of dice, called hard, had ???(152)
the imagination of his subjects, teaching them that chance
alone-a-roll of the dice guided the ???(153) of men. All
who played this game of fortune lost their ???(155) in the
virtues of courage, prudence, wisdom and hope. It bred a
fatalism that was ???(155) the spirit of the kingdom.
Raja Balhait commissioned Sissa, an intelligent courter at
his court to find an answer to this ???(156) After much
???(157) the clever Sissa invented another game.
Chaturanga, the exact ???(158) of hard, in which the four
elements of the Indian army were the key pleces. In the
game these pieces-chariots, horses, elephants and foot
soldiers-joined with a royal counselor to defend their king
and defeat the enemy. Forceful ???(159) was demanded of the
players?not luck. Chaturanga soon became more popular than
hard, and the ???(160) to the Kingdom was over.

81. (a) concerned
(b) confident
(c) ignorant
(d) indifferent
(e) partisan
Ans: ( a ) concerned

82. (a) propelled
(b) enshrined
(c) captured
(d) activated
(e) enhanced
Ans: ( c ) captured

83. (a) communities
(b) ways
(c) abnormalities
(d) destiny
(e) groups
Ans: ( d ) destiny

84. (a) bravado
(b) interest
(c) peace
(d) wealth
(e) faith
Ans: ( b ) interest

85. (a) appalling
(b) crushing
(c) moistening
(d) promoting
(e) overwhelming
Ans: ( e ) overwhelming

86. (a) apprehension
(b) risk
(c) problem
(d) game
(e) destiny
Ans: ( e ) destiny

87. (a) deliberation
(b) absorption
(c) insight
(d) hesitation
(e) reluctance
Ans: ( a ) deliberation

88. (a) nature
(b) equivalent
(c) picture
(d) opposite
(e) replica
Ans: ( d ) opposite

89. (a) prediction
(b) concentration
(c) manipulation
(d) attack
(e) fortune
Ans: ( b ) concentration

90. (a) devastation
(b) anxiety
(c) impeachment
(d) nuisance
(e) threat
Ans: ( e ) threat

Directions (Qs. 91?95) : Read each sentence to find out
whether there is any grammatical error in it. The error, if
any, will be in one part of the sentence. The number of
that part is the answer. If there is not error, the answer
is ?E?. (Ignore errors of punctuation, if any)

91. If your don?t (a) / understand any of these words (b) /
you could (c) / always refer a dictionary. (d) / No error (e)
Ans: ( e )

92. Tea is so hot (a) / that she (b) / can (c) / take it.
(d) / No error (e)
Ans: ( a )

93. The teacher said (a) / that the earth (b) / moves round
(c) / the sun. (d) / No error (e)
Ans: ( e )

94. He told to me (a) / that he (b) / was going away (c) /
the next day. (d) / No error (e)
Ans: ( b )

95. The lecturer says (a) / that Solomon won the respect (b)
/ of all races and (c) / classes by his justice. (d) / No
error (e)
Ans: ( e )

Directions (Qs. 96?100) : In each of the following
questions, select the most appropriate word from among the
five words given below the sentence to fill in the blanks in
the sentence so as to complete it meaningfully.

96. Sunil was ???asleep and could not be easily awakened.
(a) high
(b) fast
(c) severe
(d) total
(e) has
Ans: ( b ) fast

97. The vehicle did not come to a sudden halt since he
braked ???
(a) immediately
(b) silently
(c) gently
(d) completely
(e) detected
Ans: ( c ) gently

98. I saw him going escorted ??? two policemen.
(a) with
(b) against
(c) by
(d) on
(e) for
Ans: ( c ) by

99. Madhav is a sick man and has to be taken to the doctor ???
(a) usually
(b) timely
(c) seldom
(d) frequently
(e) avoided
Ans: ( d ) frequently

100. The child was left in the servants ???
(a) care
(b) duty
(c) work
(d) help
(e) innocence
Ans: ( a ) care

Directions (Qs. 101?105) :Rearrange the following six
sentences I, II, III, IV, V and VI in proper sequence so as
to form a meaningful paragraph. Then answer the questions
given below them.

I. We were interested by contrast in understanding what
lessons actual teams and non-teams had for others to choose
to struggle with change and performance.
II. Still, we suspected that most of these focused on
persuading readers that ?terms are important?.
III. After all we thought teams are a well-known subject and
there must be a thousand books on the subject already.
IV. By going down this path we hope to discover something to
say that was different from most books on the subject.
V. We approached the idea of a book on teams cautiously.
VI. Alternatively they focused on providing you to advise on
building teams as an objective in it self.

101. Which of the following will be the SECOND sentence?
(a) I
(b) II
(c) VI
(d) III
(e) IV
Ans: ( d ) III

102. Which of the following will be the FIRST sentence ?
(a) V
(b) I
(c) II
(d) III
(e) IV
Ans: ( a ) V

103. Which of the following will be the THIRD sentence ?
(a) V
(b) III
(c) II
(d) VI
(e) IV
Ans: ( c ) II

104. Which of the following will be the FIFTH sentence ?
(a) III
(b) IV
(c) II
(d) VI
(e) I
Ans: ( e ) I

105. Which of the following will be the LAST sentence ?
(a) III
(b) IV
(c) V
(d) VI
(e) II
Ans: ( b ) IV

Directions (Qs. 106?110) : In each sentence below four
words have been printed in bold type, which are numbered
(A), (B), (C), (D). One of these words may be either
wrongly spelt or inappropriate in the context of the
sentence. The number of that word is the answer. If all
the four words are spelt correctly, the answer is (E), i.e.,
all correct.

106. He had experienced (a) / a purposefully (b) /
discussion (c) / on topics of our interest. (d) / All
correct (e)
Ans: ( b )

107. To solve a (a) / problem, one needs to have (b) /
intelligent and firm (c) / determination. (d) / All correct (e)
Ans: ( c )

108. Many legends (a) / superstions endow the moon with (b)
/ a beauty and mistery which will (c) / linger for countless
years. (d) / All correct (e)
Ans: ( c )

109. People in our country are distressed (a) / by the spate
of strikes, an almost (b) / perpetual go-slow and (c) /
increadibly low productivity. (d) / All correct (e)
Ans: ( d )

110. The faces of the (a) / twins were so (b) / identical
that we could not (c) / differentiate between them. (d) /
All correct (e)
Ans: ( c )

Directions (Qs. 111?115) : In each of the following
questions five words are given, which are numbered I, II,
III, IV and V. By using all the five words, each only once,
you have to frame a meaningful and grammatically correct
sentence. The correct order of the words is the answer.
Choose from the five alternatives the one having the correct
order of words and mark it as your answer on the answer sheet.

111. I. interested II. in III. children
IV. are V. games
(a) III, IV, I, II, V
(b) V, IV, I, II, III
(c) III, IV, V, I, II
(d) III, V, IV, I, II
(e) III, IV, II, V, I
Ans: ( a ) III, IV, I, II, V

112. I. was II. to III. he
VI. go V. ready
(a) III, I, II, IV, V
(b) I, III, IV, II, V
(c) III, IV, II, V, I
(d) I, II, IV, III, V
(e) III, I, V, II, IV
Ans: ( e ) III, I, V, II, IV

113. I. found II. lost III. his
IV. book V. we
(a) V, II, III, I, IV
(b) III, IV, II, V, I
(c) V, I, III, II, IV
(d) V, II, III, IV, I
(e) III, IV, V, II, I
Ans: ( c ) V, I, III, II, IV

114. I. of II. he III. proud
IV. me V. was
(a) V, II, IV, I, III
(b) II, V, IV, I, III
(c) IV, V, III, I, II
(d) II, V, III, I, IV
(e) II, III, V, I, IV
Ans: ( d ) II, III, V, I, IV

115. I. decision II. happy III. made
IV. your V. me
(a) IV, III, V, II, I
(b) IV, I, III, V, II
(c) II, I, III, V, IV
(d) IV, I, V, III, II
(e) II, III, V, IV, I
Ans: ( b ) IV, I, III, V, II

Directions (Qs. 116?120) : In the following questions, five
words are given out of which only one is mis-spelt. Find
that mis-spelt word and indicate it in the Answer Sheet.

116. (a) combination
(b) exageration
(c) hallucination
(d) admonition
(e) clinical
Ans: ( b ) exageration

117. (a) sacrosanct
(b) sacrelege
(c) sacred
(d) sacrament
(e) segment
Ans: ( b ) sacrelege

118. (a) allitration
(b) allowance
(c) almighty
(d) almanac
(e) illicit
Ans: ( a ) allitration

119. (a) idiosyncrasy
(b) idealise
(c) idiosy
(d) ideology
(e) ieonoclass
Ans: ( c ) idiosy

120. (a) jaundise
(b) jasmine
(c) jevelin
(d) jarving
(e) judgement
Ans: ( a ) jaundise

Directions (Qs. 121?130) : Read the following passage
carefully and answer the questions given below it. Certain
words/phrases in the passage are printed in bold to help you
locate them while answering some of the questions.

Nature is an infinite source of beauty. Sunrise and
sunset, mountains and rivers, lakes and glaciers, forests
and fields provide joy and bliss to the human mind and heart
for hours together. Everything in nature is splendid and
divine. Everyday and every season of the year has a
peculiar beauty to unfold. Only one should have eyes to
behold it and a heart to feel it like the English poet
William Wordsworth who after seeing daffodils said: ?And
then my heart with pleasure fills and dances with the
daffodils?.
Nature is a great teacher. The early man was thrilled with
beauty and wonders of nature. The Aryans worshipped nature.
One can learn the lessons in the vast school of nature.
Unfortunately the strife, the stress and the tension of
modern life have made people immune to beauties of nature.
Their life is so full of care that they have no time to
stand and stare. They cannot enjoy the beauty of lowing
rivers, swinging trees, flying birds and majestic mountains
and hills. There is however, a cry to go back to village
from the concrete and artificial jungle of cities. Hence
the town planners of today pay special attention to provide
enough number of natural scenic spots in town planning. To
develop a balanced personality, one needs to have a healthy
attitude which can make us appreciate and enjoy the beauty
of nature.
There is other balm to soothe our tired soul and listless
mind than the infinite nature all around us. We should
enjoy it fully to lead a balanced and harmonious life, full
of peace and tranquility.

121. Which of the following words has the SAME meaning as
the word care as used in the passage ?
(a) grief
(b) want
(c) needs
(d) pleasure
(e) prejudices
Ans: ( a ) grief

122. Choose the word which is most OPPOSITE in meaning of
the word unfold as used in the passage.
(a) declare
(b) conceal
(c) describe
(d) perpetuate
(e) evolve
Ans: ( b ) conceal

123. Which of the following statements is not made in the
passage about Nature?
(a) Nature is an infinite source of beauty
(b) Everything in nature is splendid and divine
(c) Nature is a great teacher
(d) The Aryans worshipped Nature
(e) The early man was scared of Nature
Ans: ( e ) The early man was scared of Nature

124. What is needed to develop balanced personality?
(a) interpersonal skills
(b) reading poetry
(c) healthy attitude
(d) going back to villages
(e) None of these
Ans: ( c ) healthy attitude

125. Why do people not enjoy the beauty of Nature ?
(a) They are running after material pleasures
(b) They do not consider nature as balm to soothe their
fired minds
(c) Their life is full of worries and tensions
(d) They are afraid of nature
(e) None of these
Ans: ( c ) Their life is full of worries and tensions

126. What should we do to enjoy tranquil life ?
(a) Get totally immersed in our daily routine
(b) Believe that nature is infinite source of beauty
(c) Lead a disciplined and dedicated life
(d) Enjoy the nature around us
(e) Form a habit of daily physical exercise
Ans: ( d ) Enjoy the nature around us

127. What are the town planners doing today?
(a) Providing facilities for enjoying nature
(b) Establishing balance between concrete and artificial
jungle of cities
(c) Supporting the cry to go back to villages
(d) Making efforts to inculcate healthy attitude among people
(e) None of these
Ans: ( a ) Providing facilities for enjoying nature

128. Choose the word which is most OPPOSITE in meaning of
the word listless as used in the passage
(a) active
(b) progressive
(c) backward
(d) hidden
(e) impure
Ans: ( a ) active

129. Choose the word which is most OPPOSITE in meaning of
the word soothe as used in the passage ?
(a) stabilize
(b) excite
(c) propagate
(d) nature
(e) strengthen
Ans: ( b ) excite

130. According to the author of the passage, Nature
(a) is the ultimate salvation of man
(b) is the creator of this universe
(c) brings uniformity in all seasons
(d) maintains homeostasis in human beings
(e) is abundantly glorious and divine
Ans: ( e ) is abundantly glorious and divine

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2009-05-23T20:40:00.000-07:00

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J2EE Interview Questions and Answers

2009-04-27T03:21:00.000-07:00

What is J2EE?

J2EE is a Java 2 Enterprise Edition. J2EE is an environment for developing and deploying enterprise applications. J2EE specification is defined by Sun Microsystems Inc. The J2EE platform is lies of a set of services, application programming interfaces (APIs), and protocols, which provides the functionality necessary for developing multi-tiered, web-based applications. The J2EE platform is one of the richest platform for the development and deployment of enterprise applications.

What do you understand by a J2EE module?

A J2EE module is a software building block that consists of one or more than J2EE components of the same container type along with one deployment descriptor of that type. J2EE specification specifies four characters of modules:
a) Web module
b) EJB module
c) resource adapter
d) application client and

Modules can also be assembled into J2EE applications.

What is J2EE component?

J2EE component is a collected functional software unit supported by a container and configurable at deployment time. The J2EE specification shows the following J2EE component part:

* Application clients and applets that run on the client machine.

* Java servlet and JavaServer Pages (JSP) technology are Web components that run on the server machine.

* Enterprise JavaBeans (EJB) (enterprise beans) are business components that run on the server.

What is bean-managed transaction ?
Transaction whose boundaries are defined by an enterprise bean.

What is binding (XML) ?
Generating the code needed to process a well-defined portion of XML data.

What is binding (JSF) ?
Wiring UI components to back-end data sources such as backing bean properties.

What is build file ?
The XML file that contains one or more asant targets.

What is business logic ?
The code that implements the functionality of an application.

What is business method ?
A method of an enterprise bean that implements the business logic or rules of an application.

What is callback methods ?
Component methods called by the container to notify the component of important events in its life cycle.

What is caller principal ?
It is principal that identifies the invoker of the enterprise bean method.

What is caller ?
Same as caller principal.

What are the components of web module?

There are the following modules:
a) Java classes
b) JSP files
c) gif and html files and
d) web component deployment descriptors

Differentiate .ear, .jar and .war files?

These files are created for different uses .These files are only zipped file using java jar tool. Here is the description of these files:

.ear files: The .ear file comprises the EJB modules of the application.
.jar files: are with the .jar extension. The .jar files comprises the libraries, resources and accessories files like property files.
.war files: are with the .war extension. The war file comprises the web application that can be deployed on the any servlet/jsp container. The .war file contains jsp, html, JavaScript and other files for necessary for the development of web applications.

Differentiate between Session Bean and Entity Bean?

Session Bean: Session is one of the EJB and it shows a single client inside the Application Server. Stateless session bean is easy to develop and its efficient. As compare to entity beans session beans needs few server resources.

Entity Bean: An entity bean represents persistent global data from the database. Entity beans data are stored into database.

Why J2EE is suitable for the development of distributed multi-tiered enterprise applications?

J2EE application program allows the developers to design and implement the business logic into components according to business requirement. J2EE architecture allows the development of multi-tired applications and the developed applications can be installed on different machines depending on the tier in the multi-tiered J2EE environment . The J2EE application parts are:

a) Web-tier components.
b) Client-tier components .
c) Business-tier components .
d) Enterprise information system (EIS)-tier software.

what is a container?

containers are the interface between a component and the low-level platform specific functionality that supports the component.

What services provided by a container?

The services provided by container are as follows:
a) Transaction management for the bean
b) Instance pooling for the bean
c) Persistence
d) Remote access
e) Lifecycle management
f) Database-connection pooling
g) Security

What are types of J2EE clients?

a) Java-Web Start
b) clients Applets
c) Web applications
d) Wireless clients

What is Deployment Descriptor?

A deployment descriptor is simply an XML(Extensible Markup Language) file with the extension of .xml.. Application servers reads the deployment descriptor to deploy the components contained in the deployment unit. As in: ejb-jar.xml file is used to describe the setting of the EJB.

What is JTA and JTS?

JTA stands for Java Transaction API and JTS stands for Java Transaction Service. JTA provides a standard interface which allows the developers to demarcate transactions . JTA is a high level transaction interface used by the application code to control the transaction.

What is JAXP?

The Java API for XML Processing (JAXP) enables applications to parse and transform XML documents independent of a particular XML processing implementation.

What is J2EE Connector architecture?

J2EE Connector Architecture (JCA) is a Java-based technology solution for connecting application servers and enterprise information systems (EIS) as part of enterprise application integration (EAI) solutions.

differentiate between Java Bean and Enterprise Java Bean?

Java Bean as is a plain java class with member variables and getter setter methods. Java Beans are defined under JavaBeans specification as Java-Based software component model. which lets in the features like introspection, customization, events, properties and persistence.

Differentiate JTS and JTA?

JTS shows the implementation of a Java transaction manager. JTS specifies the implementation of a Transaction Manager which supports the Java Transaction API (JTA) 1.0.
The JTA shows an architecture for building transactional application servers and defines a set of interfaces for various components of this architecture. The components are: the application, resource managers, and the application server.

Can Entity Beans have no create() methods?

Entity Beans have no create() method, when entity bean is not used to store the data in the database. In this case entity bean is used to retrieve the data from database.

What are the call back methods in Session bean?

Callback methods are called by the container to notify the important events to the beans in its life cycle. The callback methods example are ejbCreate(), ejbPassivate(), and ejbActivate().

What is bean managed transaction?

In the EJB transactions can be maintained by the container or developer can write own code to maintain the transaction. If a developer doesn’t want a Container to manage transactions, developer can write own code to maintain the database transaction.

What are transaction isolation levels in EJB?

There are four levels :
* Serializable
* Committed Read
* Repeatable Read
* Uncommitted Read

What is "application client" ?
Application clients have access to some J2EE platform APIs.

What is "application client container" ?
A container that supports application client components.

What is "application client module" ?
A software unit that have one or more classes and an application client deployment descriptor.

What is "application component provider" ?
A vendor that provides the Java classes that implement components' methods, JSP page definitions, and any required deployment descriptors.

What are "application configuration resource file" ?
An XML file used to configure resources for a Java Server Faces application.

What is "archiving" ?

Process of saving the state of an object and restoring it.

What is "asant" ?
A Java-based build tool that can be extended using Java classes. The configuration files are XML-based, calling out a target tree where various tasks get executed.

What is "attribute"?
A qualifier on an XML tag that provides additional information to the client .

What is authentication ?
Process that verifies the identity of a user, device, or other entity in a computer system.

What is authorization ?
The process by which access to a method or resource is determined.

What is authorization constraint ?
An rule that determines who is permitted to access a Web resource collection.

What is B2B ?
B2B stands for Business-to-business process.

What is backing bean ?

The backing bean defines properties for the components on the page and methods that perform processing for the component.

What is basic authentication ?
An authentication mechanism in which a Web server authenticates an entity via a user name and password obtained using the Web application's built-in authentication mechanism.

What is bean-managed persistence ?
The mechanism whereby data transfer between an entity bean's variables and a resource manager is managed by the entity bean.

http://worldinfosoft.com/interviewquestions/j2eeinterview.html

Swing Interview Questions and Answers

2009-04-27T03:16:00.000-07:00

Define AWT?

AWT stands for Abstract Window Toolkit. AWT enables programmers to develop Java applications with GUI components, such as windows, and buttons.

Define JFC?

JFC stands for Java Foundation Classes. The Java Foundation Classes (JFC) are a set of Java class libraries created as part of Java 2 Platform, Standard Edition (J2SE) to support building graphics user interface (GUI) and graphics functionality for client applications.

Differentiate between Swing and AWT?

AWT is heavy-weight components, but Swing is light-weight components.

AWT is OS dependent because it uses native components, But Swing components are OS independent.

We can change the look and feel in Swing which is not possible in AWT.

Swing takes less memory compared to AWT.

For drawing AWT uses screen rendering where Swing uses double buffering.

Define heavyweight components ?

A heavyweight component is that is associated with its own native screen resource.

Define lightweight component?

A lightweight component is that who "borrows" the screen resource of an ancestor.

Define double buffering ?

Double buffering is the process of use of two buffers rather than one to temporarily hold data being moved to and from an I/O device.

Click Here to find more solution

JDBC Interview Questions and Answers

2009-04-27T03:09:00.000-07:00

How can you establish connection?
To establish a connection you need to have the appropriate driver connect to the DBMS.
The following line of code we use:

String url = “jdbc:odbc:Fred”;
Connection con = DriverManager.getConnection(url, “Fernanda”, “J8?);

Define different types of Statements?
There are three types of statements
• Regular statement
• prepared statement
• callable statement

What are the components of JDBC?
The two major components of JDBC are Connection Pooling and Data Sources.

Define metadata?
Metadata is data about data.
In JDBC, there are two types
1. Describing information about the Result set object. i
2. describes about the database connection

Differentiate between local and global transaction?
A transaction is atomic unit of Work.

Transactions can be divided into two categories.

1.Local Transactions: These transactions are confined to the objects which reside inside one particular JVM.

2.Global Transactions:These transactions may encapsulate objects which are distributed on various JVM's.

Many More Interview Questions

Microsoft may be a winner in Oracle-Sun deal

2009-04-27T01:17:00.001-07:00

Microsoft Corp. has had few critics more vociferious than Oracle CEO Larry Ellison and Sun Chairman Scott McNealy. So with Oracle planning to acquire Sun, Microsoft should be worried, right?

Not necessarily.

If Oracle retools itself as a full-fledged systems vendor, as Ellison suggested that it might, hardware makers such as Dell Inc. and Hewlett-Packard Co. might cozy up more with Microsoft as a business partner.

HP and Oracle teamed up last year to roll out the jointly branded Database Machine and Exadata Storage Server, which combine Oracle's software and HP's ProLiant servers. Oracle is selling the systems, while HP handles delivery and services the hardware.

But Sanford C. Bernstein & Co. analyst Toni Sacconaghi wrote in a research note last week that HP "is likely to push alternatives to [Oracle] when possible, given that they are now direct competitors in the hardware space."

"The hardware business is king [for server vendors], and anything that threatens that becomes your mortal enemy," noted Miko Matsumura, a former Sun executive who is deputy chief technology officer at Software AG.

Some analysts expect Oracle to sell Sun's hardware business to a company such as Fujitsu Ltd., which makes Sparc-based systems. But Ellison, while not divulging any Sparc-related plans, said that the acquisition could enable Oracle to develop fully integrated systems.

You may be a victim of software counterfeiting

2009-04-14T23:10:00.000-07:00

This copy of windows did not pass genuine windows validation.
Ask for genuine microsoft software
To fix and Resolve the problem you may follow these steps:

After installing your genuine copy of Microsoft Windows XP you are prompted with a “Your software is counterfeit” error message at startup. Even after visiting the www.microsoft.com/genuine/ site and validating, you still get the above message popping up after 2 or 3 boots. There is an easy solution to this and I would like you to follow the steps below to fix the issue.

1. C:\Windows\Downloaded Program Files

Within that folder, remove any files or folders associated with .WGA

2. Safe Mode

Reboot your computer and as soon as Windows logs off, start repeatively tapping the F8 Key on your keyboard.
As soon as you see the Windows Advanced Startup options select Safe Mode within Safe Mode get yourself into these folders…
C:\Windows\System32 (Rename wgatray.exe to wgatrayold.exe)
C:\Windows\System32\dllcache (Rename wgatray.exe to wgatrayold.exe)
Note: Dllcache is a hidden folder, to view hidden folders do the following, go to Start, Control Panel, Folder Options,
Select the view Tab and under the Hidden Files option, select Show hidden files and folders

3. Safe Mode Registry

Click on Start, Run and within the open dialog box type regedit and click OK.
Within the Registry Editor navigate your self to
HKEY_Local_Machine\Software\Microsoft\WindowsNT\CurrentVersion\Winlogon\Notify\WGALOGON
Right Click and Export the WGALOGON Folder (this should be saved onto your machine for backup purposes)
After Exporting the folder, DELETE the WGALOGON folder
After deleting close all applications and Restart your machine back to Normal Mode

4. www.microsoft.com/genuine

Get into the site above and manually re-validate your copy of Windows.
After being prompt of a successful validation, Restart your Machine.

Advantage of Hibernate over JDBC

2009-04-11T21:03:00.000-07:00

Hibernate provides data base independent query mechanism but JDBC does not. You need to write database specific query.
Hibernate treats tables as objects and so you can work with classes and objects instead of queries and result sets but its not so with jdbc.
Hibernate provides its own powerful query language called HQL (Hibernate Query Language). Using HQL you can express queries in a familiar SQL like syntax. It selects the best way to execute the database operations. JDBC supports only native Structured Query Language (SQL) and you need to write the effective query to access database.
Hibernate eliminates need for repetitive SQL.
Hibernate provides API to handle all create-read-update-delete (CRUD) operations i.e. no SQL is required.
Hibernate makes the development fast because it relieves you from manual handling of persistent data
You don’t require query tuning because hibernate does it automatically using Criteria Queries. But you need to tune queries while using jdbc.
Hibernate supports query caching for better performance.
Hibernate provides connection pooling by just mentioning a few lines in configuration file. But you need to write connection pooling code in case of jdbc.
XML file in hibernate lets you specify all configuration information and relations between tables, which increases the readability and allows changes more easily.
Hibernate supports lazy loading. Objects can also be loaded on startup by turning off the lazy attribute. Jbdc does not support it.
Hibernate supports Automatic Versioning and Time Stamping but jdbc does not.

For More Details You can visit to www.worldinfosoft.com

Java Technology Blogs: Core JAVA Interview Questions & Answers-2

2009-03-22T07:40:00.000-07:00

Java Technology Blogs: Core JAVA Interview Questions & Answers-2

WorldInfoSoft.com

2009-03-15T00:35:00.000-07:00

WORLDINFOSOFT.COM is the very good tutorial site, where you can found many more tutorial about
core java
jsp
servlet
php
mysql
j2me
advance java
j2ee
swing
c
c++
html
xhtml
dhtml
xml
wml
xslt
css
jdbc
hibernate

Core JAVA Interview Questions & Answers-1

2009-01-25T22:52:00.000-08:00

What is the most important feature of Java?
Java is a platform independent language.
What do you mean by platform independence?
Platform independence means that we can write and compile the java code in one platform like (Windows) and we can execute the class in any other supported platform like (Linux, Solaris etc).
Is JVM platform independent?
JVM is not platform independent. It is a platform specific run time implementation provided by the vendor.
What is a JVM?
JVM is Java Virtual Machine which is a run time environment for the compiled java class files.
Difference between JRE/JVM/JDK? To See in Details Click on this Link:- http://javasks.blogspot.com/2009/01/difference-between-jre-jvm-and-jdk.html
What is Externalizable? - Externalizable is an Interface that covers Serializable Interface. It sends data into Streams in Compressed Format. It has two methods, that is: writeExternal(ObjectOuput out) and readExternal(ObjectInput in).
What is a pointer and does Java support pointers?
Pointer is a reference deal to a memory location. Improper treating of pointers leads to memory escapes and reliability issues hence Java doesn't support the usage of pointers.
Does Java support multiple inheritance?
Java doesn't support multiple inheritance.
Is Java a pure object oriented language?
Java is not a pure object oriented language because it uses primitive data types.
What is difference between Path and Classpath?
Path and Classpath are operating system level environment variables. Path is used define where the system can find the executables (.exe) files and Classpath is used to specify the location .class files.

For More Details: http://www.worldinfosoft.com/interviewquestions/corejavainterview.html

Core JAVA Interview Questions & Answers-2

2009-01-25T22:51:00.000-08:00

Can there be an abstract class with no abstract methods in it? - Yes
Can an Interface be final? - No
What are local variables?
Local variables are those which are declared within a block of code like methods. Local variables should be initialized before accessing them.

Can an Interface have an inner class? - Yes.

 public interface xyz{
 static int i=0;
 void ss();

 class abc{
  abc(){
   int j;
   System.out.println("In side the interface");
  };

  public static void main(String abc[]){
   System.out.println("Interface is in");
  }
 }
}

Can we define private and protected modifiers for variables in interfaces? - No
What modifiers are allowed for methods in an Interface? - Only public and abstract modifiers are allowed for methods in interfaces.
What is a local, member and a class variable? - Which variable declared within a method that is called “local” variables, which variable declared within the class (not within any methods) are called “member” variables (global variables) and which variables declared within the class (not within any methods and are defined as “static”) are called class variables.
What are the different identifier states of a Thread? - The different identifiers of a Thread are: R - Running or runnable thread, S - Suspended thread, CW - Thread waiting on a condition variable, MW - Thread waiting on a monitor lock, MS - Thread suspended waiting on a monitor lock
What are some alternatives to inheritance? - Delegation is an alternative to inheritance. Delegation means that you include an instance of another class as an instance variable, and forward messages to the instance. It is often better than inheritance because it forces you to think about each message you forward, because the instance is of a known class, rather than a new class, and because it doesn’t force you to accept all the methods of the super class: you can provide only the methods that really make sense. On the other hand, it makes you write more code, and it is more difficult to re-use (because it is not a subclass).
What is instance variables?
Instance variables are those variable which is defined at the class level. Instance variables need not be initialized before using them as they are automatically initialized to their default values.

For More: http://worldinfosoft.com/interviewquestions/corejavainterview.html

Core JAVA Interview Questions & Answers-3

2009-01-25T22:50:00.000-08:00

What is constant variable in Java?
The constant variable should be declared as static and final. So only one copy of the variable exists for all instances of the class and the value can't be changed.
Should a main method be mandatory declared in all java classes?
No it is not required. main method should be defined only if the source class is a java application.
What is the return type of the main method?
Main method doesn't return anything therefore it declared void.
Why is the main method declared static?
main method is called by the JVM yet before the instantiation of the class hence it is declared as static.
What is the argument of main method?
The main method accepts an array type of String object as an argument.
Can main method be overloaded?
Yes. You can have any number of main methods with different method signature and implementation in the class.
Can a main method be declared final?
Yes. Any inheriting class will not be able to have it's own default main method.
Why isn’t there operator overloading? - Because C++ has proven by example that operator overloading makes code almost impossible to maintain. In fact there very nearly wasn’t even method overloading in Java, but it was thought that this was too useful for some very basic methods like print(). Note that some of the classes like DataOutputStream have unoverloaded methods like writeInt() and writeByte().
How do I convert a numeric IP address like 192.168.10.204 into a hostname like javasks.blogspot.com?
```
 String hostname = InetAddress.getByName("192.168.10.204").getHostName();
```
Why do threads block on I/O? - Threads block on I/O (that is enters in the waiting state) so that other threads may execute while the I/O operation is performed.

For More: http://worldinfosoft.com/interviewquestions/corejavainterview.html

Core JAVA Interview Questions & Answers-4

2009-01-25T22:48:00.000-08:00

What is synchronization and why is it important? - With respect to multithreading, synchronization is the capability to control the access of multiple threads to shared resources. Without synchronization, it is possible for one thread to modify a shared object while another thread is in the process of using or updating that object’s value. This often leads to significant errors.
Is null a keyword? - No, The null value is not a keyword.
How many bits are used to represent Unicode, ASCII, UTF-16, and UTF-8 characters? - Unicode requires 16 bits and ASCII require 7 bits. while the ASCII character set uses only 7 bits, it is usually represented as 8 bits. UTF-8 represents characters using 8, 16, and 18 bit patterns. UTF-16 uses 16-bit and larger bit patterns.
What are wrapped classes? - Wrapped classes are classes that allow primitive types to be accessed as objects.
What is a native method? - A native method is a method that is implemented in a language other than Java.
What is the catch or declare rule for method declarations? - If a checked exception may be thrown within the body of a method, the method must either catch the exception or declare it in its throws clause.
What is the range of the char type? - The range of the char type is 0 to 2^16 - 1.

For More: http://worldinfosoft.com/interviewquestions/corejavainterview.html

Difference Between jre jvm and jdk

2009-01-23T11:27:00.000-08:00

JDK (Java Development Kit)

JDK= JDK tools + JRE

JRE = JVM + Java Packages Classes(like util, math, lang, awt,swing etc)+runtime libraries.

JDK contains tools required to develop the Java programs, and JRE to run the programs. The tools include compiler (javac.exe), Java application launcher (java.exe), Appletviewer, etc…

JAVA Compiler converts java code into byte code. and java application launcher opens a JRE, loads the class, and invokes its main method.

If you want to write and compile your own programs, you need JDK. If you just want to run your java programs, JRE is sufficient. JRE is targeted for execution of Java files

You can create a Java file (with the help of Java packages), compile a Java file and run a java file. JDK is mainly targeted for java development.

JRE (Java Runtime Environment)
Java Runtime Environment contains JVM, class libraries, and other supporting files. It does not contain any development tools such as compiler, debugger, etc. Actually JVM runs the program, and it uses the class libraries, and other supporting files provided in JRE. If you want to run any java program, you need to have JRE installed in the system.

JVM(Java Virtual Machine)
The Java Virtual Machine provides a platform-independent way of executing code, programmers can concentrate on writing application, without having to be concerned with how or where it will run.

JDK Tools and Utilities

2009-01-23T11:15:00.000-08:00

Basic Tools:

javac
java
javadoc
apt
appletviewer
jar
jdb
javah
javap
extcheck

Security Tools:

keytool
jarsigner
policytool
kinit
klist
ktab

Internationalization Tools:

native2ascii

Remote Method Invocation (RMI) Tools:

rmic
rmiregistry
rmid
serialver

Java IDL and RMI-IIOP Tools:

tnameserv
idlj
orbd
servertool

Java Deployment Tools:

pack200
unpack200

Java Plug-in Tools:

htmlconverter

Java Web Start Tools:

javaws

For more details you can visit: http://www.worldinfosoft.com

This is a one of the best tutorial site, where you can find lots of example with full description of code and you can also prepare of your interview from this site WORLDINFOSOFT.COM.

Insert & Retrieve Image using Servlet

2009-01-17T22:29:00.000-08:00

This article show to you how to insert blob type image into mysql database table by using servlet and how to retrieve the image from table and display it on the browser. In this example servlet is used because it dynamically process the request and generate a response for java programming language. The API of the java servlet allow to software developer to add dynamic content to a web server using java. The main advantage of java servlet is, it can be executed to handle request and response objects and it can run independently.

Now, you follow these steps to insert and retrieve image from database table:

1. Create table in your database follow this query:

CREATE TABLE `picture` (
`id` int(10) NOT NULL auto_increment,
`image` blob,
PRIMARY KEY (`id`)
)

2. create a servlet to insert the image:


import java.sql.*;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

public class InsertImage extends  HttpServlet{
  public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{
    PrintWriter pw = response.getWriter();
    String connectionURL = "jdbc:mysql://localhost:3306/test";
    Connection con=null;
    try{
      Class.forName("com.mysql.jdbc.Driver").newInstance();
      con = DriverManager.getConnection(connectionURL, "root", "");
      PreparedStatement ps = con.prepareStatement("INSERT INTO pictures VALUES(?,?)");
      File file = new File("C:/images/5.jpg");
      FileInputStream fs = new FileInputStream(file);
      ps.setInt(1,1);
      ps.setBinaryStream(2,fs,fs.available());
      int i = ps.executeUpdate();
      if(i!=0){
        pw.println("image inserted successfully");
      }else{
        pw.println("problem in image insertion");
      } 
    } catch (Exception e){
      System.out.println(e);
    }
  }
}

3. create web.xml file in WEB-INF folder of your tomcat server and put this code:


<servlet>
  <servlet-name>InsertImage</servlet-name>
  <servlet-class>InsertImage</servlet-class>
</servlet> 
<servlet-mapping>
  <servlet-name>InsertImage</servlet-name>
  <url-pattern>/InsertImage</url-pattern>
</servlet-mapping>

4. create one more servlet for retrieve image from database table


import java.sql.*;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
public class RetreiveImage extends  HttpServlet{
  public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException{
    //PrintWriter pw = response.getWriter();
    String connectionURL = "jdbc:mysql://localhost:3306/test";
    java.sql.Connection con=null;
    try{
      Class.forName("com.mysql.jdbc.Driver").newInstance();
      con=DriverManager.getConnection(connectionURL,"root","");
      Statement st1=con.createStatement();
      ResultSet rs1 = st1.executeQuery("select image from pictures where id='1'");
      String imgLen="";
      if(rs1.next()){
        imgLen = rs1.getString(1);
        System.out.println(imgLen.length());
      }  
      rs1 = st1.executeQuery("select image from pictures where id='1'");
      if(rs1.next()){
        int len = imgLen.length();
        byte [] rb = new byte[len];
        InputStream readImg = rs1.getBinaryStream(1);
        int index=readImg.read(rb, 0, len);  
        System.out.println("index"+index);
        st1.close();
        response.reset();
        response.setContentType("image/jpg");
        response.getOutputStream().write(rb,0,len);
        response.getOutputStream().flush();        
      }
    } catch (Exception e){
      e.printStackTrace();
    }
  }
}

5. put this code in to your web.xml file:


<servlet>
  <servlet-name>RetreiveImage</servlet-name>
  <servlet-class>RetreiveImage</servlet-class>
</servlet> 
<servlet-mapping>
  <servlet-name>RetreiveImage</servlet-name>
  <url-pattern>/RetreiveImage</url-pattern>
</servlet-mapping>

6. Compile both servlet file into classes folder by command prompt as:

E:\apache-tomcat-6.0.14\webapps\sandeep\WEB-INF\classes> javac InsertImage.java

and

E:\apache-tomcat-6.0.14\webapps\sandeep\WEB-INF\classes> javac RetreiveImage.java

7. Run your server by startup.bat file

8. Open your browser and type on url address:

http:\\localhost:8080\sandeep\InsertImage

then you will got a success message

9. and then run the RetreiveImage servlet to display your image on browser by

http:\\localhost:8080\sandeep\RetreiveImage

10. Finally you will see the image on your browser

For more details you can visit: http://www.worldinfosoft.com

This is a one of the best tutorial site, where you can find lots of example with full description of code and you van also prepare of your interview from this site WORLDINFOSOFT.COM.

JDBC Insert Query Example

2009-01-05T07:58:00.000-08:00


import java.io.*;
import java.sql.* ;

class JDBCInsert{
  public static void main( String args[] ){
    try{
      Class.forName("com.mysql.jdbc.Driver");
      Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/dbName","root", "root") ;
      Statement stmt = conn.createStatement() ;
      int rows = stmt.executeUpdate("INSERT INTO tableName VALUES (4, 'sandeep')");
      System.out.println(rows + " Rows modified") ;
      stmt.close() ;
      conn.close() ;
    } catch(SQLException se) {
      System.out.println("SQL Exception:"+se) ;
    } catch(Exception e){
      System.out.println(e) ;
    }
  }
}

JDBC Update Query Example

2009-01-05T07:43:00.000-08:00


import java.io.*;
import java.sql.* ;

class JDBCUpdate{
  public static void main( String args[] ){
    try{
      Class.forName("com.mysql.jdbc.Driver");
      Connection conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/dbName","root", "root") ;
      Statement stmt = conn.createStatement() ;
      int rows = stmt.executeUpdate("UPDATE tableName SET columnName='' WHERE columnName=''") ;
      System.out.println(rows + " Rows modified") ;
      stmt.close() ;
      conn.close() ;
    } catch(SQLException se) {
      System.out.println("SQL Exception:"+se) ;
    } catch(Exception e){
      System.out.println(e) ;
    }
  }
}

JDBC Prepared Statement Example

2009-01-04T08:13:00.000-08:00


import    java.io.*;
import   java.sql.*;
public class JDBCPreparedStatement     {
  public static    void main   (  String args[]){
    try{
      Class.forName("com.mysql.jdbc.Driver");
      Connection c = DriverManager.getConnection("jdbc:mysql://localhost:3306/test","root", "root");
      PreparedStatement stmt = c.prepareStatement("select * from tableName");
      ResultSet rs = stmt.executeQuery();
      while(rs.next()){
        System.out.println(rs.getInt(1) + " (" + rs.getString(2) + ")");
 }
 } catch(SQLException e){
System.err.println(e);
}
}
}

MySQL Create Database

2009-01-04T05:05:00.000-08:00

In this example we are creating a databse table for establishing the connection with MySQL database by using the JDBC driver. A database is a large collection of data or information stored in our computer in a specified manner. It helps us for accessing, managing and updating the data easily. A RDBMS (Relational Database Management System) is a type of DBMS (Database Management System) which stores the data in the form of tables. So, we can view and use the same database in many different ways.

The following example Shows to you how to create a database in MYSQL:


import java.io.*;
import java.sql.*;

public class CreateDatabase{
  public static void main(String[] args) {
    Connection conn = null;
    String url = "jdbc:mysql://localhost:3306/";
    String dbname = "test";
    String driver = "com.mysql.jdbc.Driver";
    String user = "root"; 
    String pass = "root";
    Connection con = null;
    try{
      Class.forName("com.mysql.jdbc.Driver");
      con = DriverManager.getConnection (url+dbname,user,pass);
      try{
        Statement st = con.createStatement();
        BufferedReader bf = new BufferedReader(new InputStreamReader(System.in));
        System.out.println("Enter Database name:");
        String database = bf.readLine();
        st.executeUpdate("CREATE DATABASE "+database);
        System.out.println("Dtabase Created Successfully");
      } catch (SQLException s){        System.out.println("SQL Exception!");
      }
    } catch (Exception e){      e.printStackTrace();
    }
  }
}

Data Retrieval Process of JDBC

2009-01-04T02:56:00.000-08:00

There are the following steps are used by jdbc to retrieve the data

A JDBC driver would be loaded
Using the DriverManager a database Connection object would be created
Using the Connection object a Statement object would be created
Using the Statement object a SQL Select statement would be executed
SQL select statement returned a ResultSet
The ResultSet would be used to returned the rows and examine the data.

This example illustrates how to create a connection from database table and how to access row of the table:

import java.io.*;
import java.sql.*;

public class JDBCMysqlConnection {
  public static void main( String args[]) {
    Connection conn = null;
    String url = "jdbc:mysql://localhost:3306/";
    String dbname = "test";
    String driver = "com.mysql.jdbc.Driver";
    String user = "root"; 
    String pass = "root";

    try {
      Class.forName(driver).newInstance();
      con = DriverManager.getConnection(url+dbname,user,pass);
      Statement stmt = con.createStatement();
      ResultSet rs = stmt.executeQuery("select * from tableName");
      while (rs.next()){
        System.out.println("Name= " + rs.getString("name"));
      }
    } catch (SQLException e) {
      e.printStackTrace();
    } catch (Exception e) {
      e.printStackTrace();
    } finally {
      con.close();
    }
  }
}

Four Steps for Java Database Connectivity

2008-12-30T08:22:00.000-08:00

Before you can create a java jdbc connection to the database, you must first import the

java.sql package.

import java.sql.*;

The star ( * ) indicates that all of the classes in the package java.sql are to be imported.

1. Loading database driver

In this step we load the driver class by calling Class.forName() with the Driver class name as an argument. Once loaded, the Driver class creates an instance of itself. A user can connect to Database Server through JDBC Driver. Since most of the Database servers support ODBC driver therefore JDBC-ODBC Bridge driver is commonly used.

The return type of the Class.forName (String ClassName) method is “Class”. Class is in class java.lang package.

try {

Class.forName(”sun.jdbc.odbc.JdbcOdbcDriver”);

} catch(Exception e) {
System.out.println(“Driver class not loaded!”);

}

2. Creating a oracle jdbc Connection

The JDBC DriverManager class defines objects which can connect Java applications to a JDBC driver. DriverManager is considered the backbone of JDBC architecture. DriverManager class manages the JDBC drivers that are installed on the system. Its getConnection() method is used to establish a connection to a database. It uses a username, password, and a jdbc url to establish a connection to the database and returns a connection object. A jdbc Connection represents a session/connection with a specific database. Within the context of a Connection, SQL, PL/SQL statements are executed and results are returned. An application can have one or more connections with a single database, or it can have many connections with different databases. A Connection object provides metadata i.e. information about the database, tables, and fields. It also contains methods to deal with transactions.

JDBC URL Syntax:: jdbc: :

JDBC URL Example:: jdbc: : •Each driver has its own subprotocol

•Each subprotocol has its own syntax for the source. We’re using the jdbc odbc subprotocol, so the DriverManager knows to use the sun.jdbc.odbc.JdbcOdbcDriver.

try{

Connection dbConnection=DriverManager.getConnection(url,”userName”,”Password”)

}catch(SQLException e) {

System.out.println( “Driver class not loaded!” );

}

3. Creating a jdbc Statement object

Once a connection is established we can interact with the database. Connection interface defines methods for interacting with the database via the established connection. To execute SQL statements, you need to instantiate a Statement object from your connection object by using the createStatement() method.

Statement statement = dbConnection.createStatement();

A statement object is used to send and execute SQL statements to a database.

Three kinds of Statements

Statement: It execute simple sql queries without parameters. Statement createStatement() Creates an SQL Statement object.

Prepared Statement: It execute precompiled sql queries with or without parameters. PreparedStatement prepareStatement(String sql) returns a new PreparedStatement object. PreparedStatement objects are precompiled SQL statements.

Callable Statement: It execute for call to a database stored procedure. CallableStatement prepareCall(String sql) returns a new CallableStatement object. CallableStatement objects are SQL stored procedure call statements.

4. Executing a SQL statement with the Statement object, and returning a jdbc resultSet.

Statement interface defines methods that are used to interact with database via the execution of SQL statements. The Statement class has three methods for executing statements:

executeQuery()
executeUpdate()
execute()

For a SELECT statement, the method to use is executeQuery . For statements that create or modify tables, the method to use is executeUpdate.

Note: Statements that create a table, alter a table, or drop a table are all examples of DDL

statements and are executed with the method executeUpdate. execute() executes an SQL

statement that is written as String object.

ResultSet provides access to a table of data generated by executing a Statement. The table rows are retrieved in sequence. A ResultSet maintains a cursor pointing to its current row of data. The next() method is used to successively step through the rows of the tabular results.

ResultSetMetaData Interface holds information on the types and properties of the columns in a ResultSet. It is constructed from the Connection object.

Java DataBase Connectivity

2008-12-30T07:58:00.001-08:00

JDBC is a Java API for executing SQL statements and supports basic SQL functionality. The JDBC ( Java Database Connectivity) API defines interfaces and classes for writing database applications in Java by making database connections. Using JDBC you can send SQL, PL/SQL statements to almost any relational database. It provides RDBMS access by allowing you to embed SQL inside Java code. Because Java can run on a thin client, applets embedded in Web pages can contain downloadable JDBC code to enable remote database access. You will learn how to create a table, insert values into it, query the table, retrieve results, and update the table with the help of a JDBC Program example.

JDBC Architecture

In This jdbc architecture programmer connect his/her application to database by using the jdbc driver. Java application calls the JDBC library. JDBC loads a driver which talks to the database.

Fig: JDBC Architecture

For more details you can visit: http://www.worldinfosoft.com

This is a one of the best tutorial site, where you can find lots of example with full description of code and you van also prepare of your interview from this site WORLDINFOSOFT.COM.

How to install Java?

2008-12-30T07:15:00.000-08:00

What is Java and why do I need it?

Java is a programming language that allows programs to be written that can then be run on more than one type of operating system. A program written in Java can run on Windows, UNIX, Linux etc. as long as there is a Java runtime environment installed.

Where can I download Java?

You can download JRE version 6 update 11 from this url:- http://java.sun.com/javase/downloads/index.jsp
If you want to be able to write your own Java programs that you can compile and run, then you must download the SDK (Software Developers Kit) from this url:- http://java.sun.com/j2se/1.4.2/download.html

Path Setting of Java

Windows 2000/XP users may set their path by right-clicking on 'My Computer' and selecting 'Properties'. Under the 'Advanced' tab, there is a button that allows you to set the 'Environment variables'. Click on this and alter the 'Path' variable so that it also contains the path to the Java executable. For example, if you have installed Java in c:\jdk and your path is currently set to C:\WINDOWS\SYSTEM32, then you would change your path to read C:\WINDOWS\SYSTEM32;c:\jdk\bin
When you open a new command prompt, it will reflect these changes and allow you to run java programs by typing "java". If you have installed the SDK, then you will also be able to run "javac" to compile stuff.
Windows 95/98/ME users may find that their path variable is stored in a different place. Edit the c:\autoexec.bat file and add the following line at the end: SET PATH=%PATH%;c:\jdk\bin
(This also assumes that you have installed Java in c:\jdk) .
Linux, UNIX, Solaris, FreeBSD users must set their PATH variable to point to where the java binaries have been installed. Please refer to your shell documentation if you have trouble doing this. For example, if you use bash as your shell, then you would add the following line to the end of your .bashrc: export PATH=/path/to/java:$PATH.

History of Java

2008-12-28T08:15:00.000-08:00

Java was started in June 1991 by James Gosling as a project called "Oak". The main goal of Gosling to implement a virtual machine and a language that had a familiar C-like notation but with greater uniformity and simplicity than C/C++. The first public implementation was Java 1.0 in 1995. It's main objective of "Write Once, Run Anywhere", with free runtimes on any platforms that's why it called platform independent. To develop a large web application Sun invented the J2EE and J2ME.

New versions for large and small platforms (J2EE and J2ME) soon were designed with the advent of "Java 2".

Download SDK and JRE

What are Access Specifiers available in Java?

2008-12-28T06:28:00.000-08:00

Access specifiers are keywords that determines the type of access to the member of a class. These are:

Public
Protected
Private
Defaults

For more details you can visit: http://www.worldinfosoft.com

This is a one of the best tutorial site, where you can find lots of example with full description of code and you van also prepare of your interview from this site WORLDINFOSOFT.COM.

Explain about the Encapsulation in java

2008-12-28T05:47:00.000-08:00

Encapsulation is a process of binding or wrapping the data and the codes that operates on the data into a single entity. This keeps the data safe from outside interface and misuse. One way to think about encapsulation is as a protective wrapper that prevents code and data from being arbitrarily accessed by other code defined outside the wrapper.

How to explain garbage collection?

2008-12-28T05:44:00.000-08:00

Collection is one of the most important feature of Java. Garbage collection is also called automatic memory management as JVM automatically removes the unused variables/objects (value is null) from the memory. User program cann't directly free the object from memory, instead it is the job of the garbage collector to automatically into a variable when no more in use. I Java on calling free the objects that are no longer referenced by a program. Every class inherits finalize() method from java.lang.Object, the finalize() method is called by garbage collector when it determines no more references to the object exists. In Java, it is good idea to explicitly assign nullSystem.gc() and Runtime.gc(), JVM tries to recycle the unused objects, but there is no guarantee when all the objects will garbage collected.

Explain about user defined Exceptions?

2008-12-28T05:41:00.000-08:00

User defined Exceptions are the separate Exception classes defined by the user for specific purposed. An user defined can created by simply sub-classing it to the Exception class. This allows custom exceptions to be generated (using throw) and caught in the same way as normal exceptions.

Example:

class myCustomException extends Exception {
// The class simply has to exist to be an exception
}

What is Synchronization in java?

2008-12-28T05:37:00.000-08:00

Synchronization is a process of controlling the access of shared resources by the multiple threads in such a manner that only one thread can access one resource at a time. In non synchronized multithreaded application, it is possible for one thread to modify a shared object while another thread is in the process of using or updating the object's value. Synchronization prevents such type of data corruption.

E.g. Synchronizing a function:
public synchronized void Method1 () {
// Appropriate method-related code.
}

E.g. Synchronizing a block of code inside a function:
public myFunction (){
synchronized (this) {
// Synchronized code here.
}
}

What is transient variable?

2008-12-28T05:35:00.000-08:00

Transient variable can't be serialize. For example if a variable is declared as transient in a Serializable class and the class is written to an ObjectStream, the value of the variable can't be written to the stream instead when the class is retrieved from the ObjectStream the value of the variable becomes null.

Difference between an Abstract class and Interface?

2008-12-28T05:30:00.000-08:00

Differences:

Interfaces provide a form of multiple inheritance. A class can extend only one other class.
Interfaces are limited to public methods and constants with no implementation. Abstract classes can have a partial implementation, protected parts, static methods, etc.

A Class may implement several interfaces. But in case of abstract class, a class may extend only one abstract class.

Interfaces are slow as it requires extra indirection to to find corresponding method in in the actual class. Abstract classes are fast.

Similarities:

Neither Abstract classes or Interface can be instantiated.

What is Collection API?

2008-12-28T05:29:00.000-08:00

The Collection API is a set of classes and interfaces that support operation on collections of objects. These classes and interfaces are more flexible, more powerful, and more regular than the vectors, arrays, and hashtables if effectively replaces.

For more details you can visit: http://www.worldinfosoft.com

This is a one of the best tutorial site, where you can find lots of example with full description of code and you van also prepare of your interview from this site WORLDINFOSOFT.COM.

Polymorphism in java

2008-12-27T11:33:00.000-08:00

Polymorphism, allows the software developer to reuse names as well as code. Polymorphism is a natural consequence of specialization (sub classing relationship implemented via inheritance), the associated principle of substitutability, and message passing.

Different forms of Polymorphism:- From a practical programming viewpoint, polymorphism exists in three distinct forms in Java:

Method overloading
Method overriding through inheritance
Method overriding through the Java interface

Abstract class in java

2008-12-27T11:29:00.000-08:00

Java Abstract classes are used to declare common characteristics of subclasses. An abstract class cannot be instantiated. It can only be used as a superclass for other classes that extend the abstract class. Abstract classes are declared with the abstract keyword. Abstract classes are used to provide a template or design for concrete subclasses down the inheritance tree.

abstract class testAbstractClass {
protected String myString;
public String getMyString() {
return myString;
}
public abstract string anyAbstractFunction();
}

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What is a Package?

2008-12-27T09:44:00.001-08:00

A package is a namespace for organizing classes and interfaces in a logical manner. Placing your code into packages makes large software projects easier to manage. The Java platform provides an enormous class library (a set of packages) suitable for use in your own applications. This library is known as the "Application Programming Interface(API) ". Its packages represent the tasks most commonly associated with general-purpose programming.

What is Inheritance?

2008-12-27T09:42:00.000-08:00

Inheritance provides a powerful and natural mechanism for organizing and structuring your software. It is the capability of a class to use the properties and methods of another class while adding its own functionality. Object-oriented programming allows classes to inherit commonly used state and behavior from other classes by the "extends" keyword. In the image we see 'duck', 'cuckoo' and 'ostrich' inherit the all properties of 'bird' which is the super class and the 'duck', 'cuckoo' and 'ostrich' are the sub class. For Example:

public class duck extends bird
public class cuckoo extends bird
public class ostrich extends bird

What is Interface?

2008-12-27T09:40:00.000-08:00

An interface is a contract between a class and the outside world. When a class implements an interface, it promises to provide the behavior of the interface. Interfaces are similar to abstract classes but all methods are abstract and all properties are static final. As an example, we will build a Working interface for the subclasses of Man. Since this interface has the method called work(), that method must be defined in any class using the Working interface.

public interface Working {
 public void work();
}

When you create a class that uses an interface, you reference the interface with the reserved word implements Interface_list. Interface_list is one or more interfaces as multiple interfaces are allowed. Any class that implements an interface must include code for all methods in the interface. This ensures commonality between interfaced objects.

public class WorkingMan extends Man implements Working {
public WorkingMan(String name) {
  super(name);
}
public void work(){
  speak();
  System.out.println("interface implemented");
}
}

What is class?

2008-12-27T09:39:00.000-08:00

A class is a blueprint or prototype from which objects are created. In the real world, you'll often find many individual objects all of the same kind.
The following Bicycle class is one possible implementation of a bicycle:

class Bicycle {

      int cadence = 0;
      int speed = 0;
      int gear = 1;

      void changeCadence(int newValue) {
           cadence = newValue;
      }

      void changeGear(int newValue) {
           gear = newValue;
      }

      void speedUp(int increment) {
           speed = speed + increment;  
      }

      void applyBrakes(int decrement) {
           speed = speed - decrement;
      }

      void printStates() {
           System.out.println("cadence:"+cadence+" speed:"+speed+" gear:"+gear);
      }
}

What is Object?

2008-12-27T09:37:00.000-08:00

An object is a software bundle of related state and behavior. Software objects are often used to model the real-world objects that you find in everyday life. Real-world objects share two characteristics: They all have state and behavior. Dogs have state (name, color, breed, hungry) and behavior (barking, fetching, wagging tail). Bicycles also have state (current gear, current pedal cadence, current speed) and behavior (changing gear, changing pedal cadence, applying brakes). Identifying the state and behavior for real-world objects is a great way to begin thinking in terms of object-oriented programming.

Bundling code into individual software objects provides a number of benefits, including:

Modularity: The source code for an object can be written and maintained independently of the source code for other objects. Once created, an object can be easily passed around inside the system.
Information-hiding: By interacting only with an object's methods, the details of its internal implementation remain hidden from the outside world.
Code re-use: If an object already exists (perhaps written by another software developer), you can use that object in your program. This allows specialists to implement/test/debug complex, task-specific objects, which you can then trust to run in your own code.
Pluggability and debugging ease: If a particular object turns out to be problematic, you can simply remove it from your application and plug in a different object as its replacement. This is analogous to fixing mechanical problems in the real world. If a bolt breaks, you replace it, not the entire machine.

Features of Java

2008-12-27T06:55:00.000-08:00

Easy to Use:- The fundamentals of Java is based on c++ programming language. The c++ programming language is based on Object oriented so, it is easy to handle by programmer.
Reliability:- Java needed to reduce the fatal errors from programmer mistakes. With this in mind, object-oriented programming was introduced. Once data and its manipulation were packaged together in one place, it increased Java’s robustness.
Secure:- As Java was originally targeting mobile devices that would be exchanging data over networks, it was built to include a high level of security. Java is probably the most secure programming language to date.
Platform Independent:- Java was written to be a portable language that doesn't care about the operating system or the hardware of the computer. It can be run on any operating system and any machine.

What is Java?

2008-12-27T06:40:00.000-08:00

Java is a “high-level” computer programming language.
It has a set of rules that determine how the instructions are written. These rules are known as its “syntax”.
The high-level instructions are translated into numeric codes that computers can understand and execute.
Java was created by a team led by James Gosling for Sun Microsystems. When Java 1.0 was released to the public in 1996, its main focus had shifted to use on the Internet. It provided more interactivity with users by giving developers a way to produce animated webpages.
Java source code files (with a .java extension) are compiled into a format called bytecode (with a .class extension), which can then be executed by a Java interpreter. Compiled Java code can run on most computers because Java interpreters and runtime environments, known as Java Virtual Machines (JVM), exist for most operating systems, including UNIX, the Macintosh OS, and Windows. Bytecode can also be converted directly into machine language instructions by a just-in-time compiler (JIT).