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 file8. 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
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