Servlets - Page Redirection

Page redirection is a technique where the client is sent to a new location other than requested. Page redirection is generally used when a document moves to a new location or may be because of load balancing.

The simplest way of redirecting a request to another page is using method sendRedirect() of response object. Following is the signature of this method −

public void HttpServletResponse.sendRedirect(String location) 
throws IOException 

This method sends back the response to the browser along with the status code and new page location. You can also use setStatus() and setHeader() methods together to achieve the same −

.... 
String site = "http://www.newpage.com" ; 
response.setStatus(response.SC_MOVED_TEMPORARILY); 
response.setHeader("Location", site);  
.... 

Example

This example shows how a servlet performs page redirection to another location −

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

public class PageRedirect extends HttpServlet {
    
   public void doGet(HttpServletRequest request, HttpServletResponse response)
      throws ServletException, IOException {

      // Set response content type
      response.setContentType("text/html");

      // New location to be redirected
      String site = new String("http://www.photofuntoos.com");

      response.setStatus(response.SC_MOVED_TEMPORARILY);
      response.setHeader("Location", site);    
   }
} 

Now let us compile above servlet and create following entries in web.xml

....
<servlet>
   <servlet-name>PageRedirect</servlet-name>
   <servlet-class>PageRedirect</servlet-class>
</servlet>

<servlet-mapping>
   <servlet-name>PageRedirect</servlet-name>
   <url-pattern>/PageRedirect</url-pattern>
</servlet-mapping>
....

Now call this servlet using URL http://localhost:8080/PageRedirect. This would redirect you to URL http://www.photofuntoos.com.