Session Tracking in servlet

View Answers

January 30, 2009 at 4:32 AM

Hi friend,

1. URL rewritting:

package javacode;

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class UrlRewrite extends HttpServlet {

public void doGet(HttpServletRequest req, HttpServletResponse res)
throws ServletException, java.io.IOException {

res.setContentType("text/html");
java.io.PrintWriter out = res.getWriter();
String contextPath = req.getContextPath();
String encodedUrl = res.encodeURL(contextPath + "/default.jsp");

out.println("<html>");
out.println("<head>");
out.println("<title>URL Rewriter</title>");
out.println("</head>");
out.println("<body>");
out.println("<h1>This page will use URL rewriting if necessary</h2>");
out.println("Go to the default.jsp page <a href=\"" + encodedUrl + "\">here</a>.");
out.println("</body>");
out.println("</html>");

}

public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, java.io.IOException {
doGet(request, response);

}
}

---------------------------

Web.xml

<servlet>

<servlet-name>urlRewrite</servlet-name>

<servlet-class>javacode.UrlRewrite</servlet-class>

</servlet>

<servlet-mapping>

<servlet-name>urlRewrite</servlet-name>

<url-pattern>jsp/UrlRewrite</url-pattern>

</servlet-mapping>

-----------------------------------------------

January 30, 2009 at 4:35 AM

Hidden Form Fields:

package javacode;

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

public class HiddenFormDemo extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res)throws ServletException, IOException {
PrintWriter out;
res.setContentType("text/html");
out = res.getWriter();
out.println("<html><head><title>Using hidden form In servlet</title></head>");
out.println("body");
String[] item = req.getParameterValues("item");
out.println("You currently have the item in your cart:");
if(items == null){
out.println("<b>None</b>");
}
else{
out.println("<ul>");
for(int i = 0; i < items.length; i++){
out.println("<li>" + items[i]);
}
out.println("</ul>");
}

out.println("<form Action=shopingcart method="POST">");
if(items ! = null){
for(int i=0; i< items.length; i++){
out.println("<input type="hidden" name="item" value=\"" + items[i] + "\">");
}
}
out.println("woulde you link to<br>");
out.println("<input type="submit" value="Add More Item">");
out.println("<input type="submit" value="Check out">");
out.println("</form>");
out.println("</body></html>");
}
}
-------------------------------------------------

web.xml

<servlet>

<servlet-name>hiddenFormDemo</servlet-name>

<servlet-class>javacode.HiddenFormDemo</servlet-class>

</servlet>

<servlet-mapping>

<servlet-name>hiddenFormDemo</servlet-name>

<url-pattern>jsp/HiddenFormDemo</url-pattern>

</servlet-mapping>

January 30, 2009 at 4:37 AM

Cookies:

package javacode;

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

public class CookiesDemo extends HttpServlet {
public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException{
PrintWriter out;
response.setContentType("text/html");
out = response.getWriter();
Cookie cookie = new Cookie("CName","Cookie Value");
cookie.setMaxAge(100);
response.addCookie(cookie);

out.println("<HTML><HEAD><TITLE>");
out.println(" Use of cookie in servlet");
out.println("</TITLE></HEAD><BODY BGCOLOR='cyan'>");
out.println(" <b>This is a Cookie example</b>");
out.println("</BODY></HTML>");
out.close();
}
}

----------------------------------------------

web.xml

<servlet>

<servlet-name>cookiesDemo</servlet-name>

<servlet-class>javacode.CookiesDemo</servlet-class>

</servlet>

<servlet-mapping>

<servlet-name>cookiesDemo</servlet-name>

<url-pattern>jsp/CookiesDemo</url-pattern>

</servlet-mapping>

----------------------------------------------------

Visit for more information:

http://www.roseindia.net/servlets/

Thanks.

Amardeep