JAVA EE: May 2014

Thursday, 29 May 2014

Servlets : Cookies

Click here to watch in Youtube : https://www.youtube.com/watch?v=lxxYdV92LLM

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Servlets : Cookies

Servlets : Attribute

Click here to watch in Youtube : https://www.youtube.com/watch?v=iTHjj8dw9Dk

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Servlets : Attribute

Servlets : HttpSession Attribute

Click here to watch in Youtube : https://www.youtube.com/watch?v=NXMCnNxBip0

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HttpSessionAttributeDemo Project Dir Structure

FirstServlet.java

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class FirstServlet extends HttpServlet
{
    private static final long serialVersionUID = 1L;

    public void init() throws ServletException
    {
        System.out.println("----------------------------------------------");
        System.out.println(" Init method is called in "
                + this.getClass().getName());
        System.out.println("--------------------------------------------");
    }

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException
    {
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();

        String username = request.getParameter("username");
        out.print("Welcome " + username);

        HttpSession session = request.getSession();
        System.out.println("FirstServlet sessionid :" + session.getId());
        session.setAttribute("Username", username);
        session.setAttribute("Role", "Admin");

        out.print("<a href='servlet2'> : visit</a>");

        out.close();

    }

    public void destroy()
    {
        System.out.println("----------------------------------------------");
        System.out.println(" destroy method is called in "
                + this.getClass().getName());
        System.out.println("----------------------------------------------");
    }

}

SecondServlet.java

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Enumeration;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

public class SecondServlet extends HttpServlet
{
    private static final long serialVersionUID = 1L;

    public void init() throws ServletException
    {
        System.out.println("----------------------------------------------");
        System.out.println(" Init method is called in "
                + this.getClass().getName());
        System.out.println("----------------------------------------------");
    }

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException
    {
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();

        HttpSession session = request.getSession();

        System.out.println("Second Servlet sessionid :" + session.getId());

        String userName = (String) session.getAttribute("Username");
        out.print("Hello " + userName + "<br>");

        out.print("*************************************************************"
                + "<br>");

        Enumeration<String> namesEnum = session.getAttributeNames();
        while (namesEnum.hasMoreElements())
        {
            String name = (String) namesEnum.nextElement();
            String value = (String) session.getAttribute(name);
            out.print(name + ":" + value);
            out.print("<br>");

        }

        out.close();
    }

    public void destroy()
    {
        System.out.println("----------------------------------------------");
        System.out.println(" destroy method is called in "
                + this.getClass().getName());
        System.out.println("----------------------------------------------");
    }

}

web.xml

<?xml version="1.0" encoding="ISO-8859-1"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://java.sun.com/xml/ns/javaee"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
    metadata-complete="true" version="3.0">

    <display-name>HttpSessionAttributeDemo</display-name>

    <description>
        This is a simple web application with a source code organization
        based on the recommendations of the Application Developer's Guide.
    </description>

    <servlet>
        <servlet-name>s1</servlet-name>
        <servlet-class>FirstServlet</servlet-class>
    </servlet>

    <servlet-mapping>
        <servlet-name>s1</servlet-name>
        <url-pattern>/servlet1</url-pattern>
    </servlet-mapping>

    <servlet>
        <servlet-name>s2</servlet-name>
        <servlet-class>SecondServlet</servlet-class>
    </servlet>

    <servlet-mapping>
        <servlet-name>s2</servlet-name>
        <url-pattern>/servlet2</url-pattern>
    </servlet-mapping>

</web-app>

index.html

<html lang="en">
<head>
<meta charset="UTF-8">
<title>Multiple Filters Demo</title>
</head>
<body>
    <form action="servlet1" method="GET">
        
        UserName :  <input type="text" name="username" /><br /> 
        
        Password :&nbsp; &nbsp; <input type="password" name="password" /><br /> 
            
        <input type="submit" value="login" />
        
    </form>
</body>
</html>

Environment Used

JDK version :1.7.0_51
Tomcat version : 7.0.50

To Download HttpSessionAttributeDemoApp Project Click the below link

https://sites.google.com/site/javaee4321/servlets/HttpSessionAttributeDemoApp.zip?attredirects=0&d=1

See also:

Servlets Tutorial

All Design Patterns Links

Thursday, 22 May 2014

Servlets : HttpSession Interface

Click here to watch in Youtube : https://www.youtube.com/watch?v=TNAqtxBT3LQ

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Servlets : HttpSession Interface

Tuesday, 6 May 2014

Servlets : Page Redirection

Click here to watch in Youtube : https://www.youtube.com/watch?v=a-urghpboqE

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PageRedirection Project Dir Structure

PageRedirectServlet.java

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class PageRedirectServlet extends HttpServlet
{

    private static final long serialVersionUID = 1L;

    public void init() throws ServletException
    {
        System.out.println("---------------------------");
        System.out.println(" Init method is called in "
                + this.getClass().getName());
        System.out.println("---------------------------");
    }

    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.google.com");

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

    public void destroy()
    {
        System.out.println("---------------------------");
        System.out.println(" destroy method is called in "
                + this.getClass().getName());
        System.out.println("---------------------------");
    }
}

web.xml

<?xml version="1.0" encoding="ISO-8859-1"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xmlns="http://java.sun.com/xml/ns/javaee" 
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" 
metadata-complete="true" version="3.0">

  <display-name>PageRedirection</display-name>

  <description>
        This is a simple web application with a source code organization
        based on the recommendations of the Application Developer's Guide.
  </description>

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

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

</web-app>

index.html

<!DOCTYPE HTML>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>PageRedirectDemo</title>
</head>
<body>
    <li><a href="PageRedirect">PageRedirect</a></li>
</body>
</html>

Environment Used

JDK version :1.6.0_30
Tomcat version : 7.0.50

To Download PageAutoRefreshApp Project Click the below link

https://sites.google.com/site/javaee4321/servlets/PageAutoRefreshApp.zip?attredirects=0&d=1

See also:

Servlets Tutorial

All Design Patterns Links

Monday, 5 May 2014

Servlets : Send Redirect Demo[Transfer control to different domain]

Click here to watch in Youtube : https://www.youtube.com/watch?v=8LjrXsgK080

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SendRedirectDemo Project Dir Structure

MySearchServlet.java

import java.io.IOException;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class MySearchServlet extends HttpServlet
{

    private static final long serialVersionUID = 1L;

    public void init() throws ServletException
    {
        System.out.println("----------------------------------");
        System.out.println(" Init method is called in "
                + this.getClass().getName());
        System.out.println("----------------------------------");
    }

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException
    {
        String searchKey = request.getParameter("searchKey");
        response.sendRedirect("https://www.google.co.in/#q=" + searchKey);
    }

    public void destroy()
    {
        System.out.println("----------------------------------");
        System.out.println(" destroy method is called in "
                + this.getClass().getName());
        System.out.println("----------------------------------");
    }
}

web.xml

<?xml version="1.0" encoding="ISO-8859-1"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://java.sun.com/xml/ns/javaee"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
    metadata-complete="true" version="3.0">
    
    <display-name>SendRedirectDemo</display-name>
    
    <description>
        This is a simple web application with a source code organization
        based on the recommendations of the Application Developer's Guide.
    </description>
    
    <servlet>
        <servlet-name>search</servlet-name>
        <servlet-class>MySearchServlet</servlet-class>
    </servlet>
    
    <servlet-mapping>
        <servlet-name>search</servlet-name>
        <url-pattern>/search</url-pattern>
    </servlet-mapping>

</web-app>

index.html

<!DOCTYPE HTML>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>SendRedirectDemo</title>
</head>
<body>
    <li><a href="mysearch.html">mysearch</a></li>
</body>
</html>

mysearch.html

<!DOCTYPE HTML>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>SendRedirectDemo</title>
</head>
<body>
    <form action="search">
        <input type="text" name="searchKey"> 
        <input type="submit" value="Google Search">
    </form>
</body>
</html>

Environment Used

JDK version :1.6.0_30
Tomcat version : 7.0.50

To Download SendRedirectDemo_Different_ContainerApp Project Click the below link

https://sites.google.com/site/javaee4321/servlets/SendRedirectDemo_Different_ContainerApp.zip?attredirects=0&d=1

See also:

Servlets Tutorial

All Design Patterns Links

Sunday, 4 May 2014

Servlets : Send Redirect Demo[Transfer control to the Servlet which is in the Same Webcontainer]

Click here to watch in Youtube : https://www.youtube.com/watch?v=oWD-x1dIDSc

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SendRedirectDemo Project Dir Structure

LoginServlet.java

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class LoginServlet extends HttpServlet
{

    private static final long serialVersionUID = 1L;

    public void init() throws ServletException
    {
        System.out.println("--------------------------------------");
        System.out.println(" Init method is called in "
                + this.getClass().getName());
        System.out.println("--------------------------------------");
    }

    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException
    {
        response.setContentType("text/html");
        PrintWriter out = response.getWriter();

        String userName = request.getParameter("username");
        String passWord = request.getParameter("password");

        if (userName.equalsIgnoreCase("ram") && passWord.equals("ram"))
        {
            response.sendRedirect("http://localhost:8080/SendRedirectDemo/welcome");
        }
        else
        {
            out.print("Sorry UserName or Password is Wrong!");
            RequestDispatcher requestDispatcher = request
                    .getRequestDispatcher("/index.html");
            requestDispatcher.include(request, response);
        }
    }

    public void destroy()
    {
        System.out.println("----------------------------------------");
        System.out.println(" destroy method is called in "
                + this.getClass().getName());
        System.out.println("-----------------------------------------");
    }
}

WelcomeServlet.java

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class WelcomeServlet extends HttpServlet
{

    private static final long serialVersionUID = 1L;

    public void init() throws ServletException
    {
        System.out.println("--------------------------------------");
        System.out.println(" Init method is called in "
                + this.getClass().getName());
        System.out.println("--------------------------------------");
    }

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException
    {

        response.setContentType("text/html");
        PrintWriter out = response.getWriter();

        out.print("Welcome");
    }

    public void destroy()
    {
        System.out.println("--------------------------------------");
        System.out.println(" destroy method is called in "
                + this.getClass().getName());
        System.out.println("--------------------------------------");
    }
}

web.xml

<?xml version="1.0" encoding="ISO-8859-1"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
 xmlns="http://java.sun.com/xml/ns/javaee" 
 xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" 
 metadata-complete="true" version="3.0">
  
  <display-name>SendRedirectDemo</display-name>
  
  <description>
        This is a simple web application with a source code organization
        based on the recommendations of the Application Developer's Guide.
    </description>
 
  <servlet>
    <servlet-name>LoginServlet</servlet-name>
    <servlet-class>LoginServlet</servlet-class>
  </servlet>
  
  <servlet>
    <servlet-name>WelcomeServlet</servlet-name>
    <servlet-class>WelcomeServlet</servlet-class>
  </servlet>
 
  <servlet-mapping>
    <servlet-name>LoginServlet</servlet-name>
    <url-pattern>/login</url-pattern>
  </servlet-mapping>
  
  <servlet-mapping>
    <servlet-name>WelcomeServlet</servlet-name>
    <url-pattern>/welcome</url-pattern>
  </servlet-mapping>
  
</web-app>

index.html

<!DOCTYPE HTML>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>RequestDispatcherDemo</title>
</head>
<body>
    <form action="login" method="post">
        
        UserName :  <input type="text" name="username" /><br /> 
        
        Password :&nbsp; &nbsp; <input type="password" name="password" /><br /> 
            
        <input type="submit" value="login" />
        
    </form>
</body>
</html>

Environment Used

JDK version :1.6.0_30
Tomcat version : 7.0.50

To Download SendRedirectDemoApp Project Click the below link

https://sites.google.com/site/javaee4321/servlets/SendRedirectDemoApp.zip?attredirects=0&d=1

See also:

Servlets Tutorial

All Design Patterns Links

Servlets : Display HTTP Request and Response headers

Click here to watch in Youtube : https://www.youtube.com/watch?v=hHcvTVFx9S0

Click the below Image to Enlarge

DisplayAllHeaders Project Dir Structure

DisplayHeadersServlet.java

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Enumeration;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class DisplayHeadersServlet extends HttpServlet
{

    private static final long serialVersionUID = 1L;

    public void init() throws ServletException
    {

        System.out.println("\n*******************************************\n");
        System.out.println("HelloWorld servlet init method has been called");
        System.out.println("\n*******************************************\n");

    }

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException
    {

        response.setContentType("text/html");

        PrintWriter out = response.getWriter();
        String title = "HTTP Header Request Example";
        String docType = "<!doctype html public \"-//w3c//dtd html 4.0 "
                + "transitional//en\">\n";
        out.println(docType + "<html>\n" + "<head><title>" + title
                + "</title></head>\n" + "<body bgcolor=\"#f0f0f0\">\n"
                + "<h1 align=\"center\">" + title + "</h1>\n"
                + "<table width=\"100%\" border=\"1\" align=\"center\">\n"
                + "<tr bgcolor=\"#949494\">\n"
                + "<th>Header Name</th><th>Header Value(s)</th>\n" + "</tr>\n");

        Enumeration<String> headerNames = request.getHeaderNames();

        while (headerNames.hasMoreElements())
        {
            String headerName = (String) headerNames.nextElement();
            out.print("<tr><td>" + headerName + "</td>\n");
            String headerValue = request.getHeader(headerName);
            out.println("<td> " + headerValue + "</td></tr>\n");
        }
        out.println("</table>\n</body></html>");
    }

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

    public void destroy()
    {
        // do nothing.
    }
}

web.xml

<?xml version="1.0" encoding="ISO-8859-1"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xmlns="http://java.sun.com/xml/ns/javaee" 
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" 
metadata-complete="true" version="3.0">
  <display-name>ServletForm GET</display-name>
  <description>
        This is a simple web application with a source code organization
        based on the recommendations of the Application Developer's Guide.
    </description>
  <servlet>
    <servlet-name>readAllHeaders</servlet-name>
    <servlet-class>DisplayHeadersServlet</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>readAllHeaders</servlet-name>
    <url-pattern>/readAllHeaders</url-pattern>
  </servlet-mapping>
</web-app>

index.html

<!DOCTYPE HTML><html lang="en"><head>
<meta charset="UTF-8">
<title>Order Pizza</title>
</head>
<body>
<p>
<h3>Order Pizza</H3>
<p></p>
<ul>
    <li><a href="pizza.html">Order Pizza</a></li>
</ul>
</body></html>

pizza.html

<html>
<head>
<title>Retrieving All Parameters</title>
 </head>
<body>
<h4>Order your Pizza Here</h4>
<form action="readAllHeaders" method="POST">
<b>Name</b> <input type="text" name="name"><br><br>
<b>Select the Crust:</b>
<select name = "crust">
<option value="pan">Pan</option>
<option value="thin">Thin Crust</option>
<option value="deep">Deep Crust</option>
<option value="cheese">Cheese Burst</option>
</select> <br><br>
<b>Toppings: </b><br>
<input type="checkbox" name="toppings" value="peas">Peas<br>
<input type="checkbox" name="toppings" value="paneer">Paneer<br>
<input type="checkbox" name="toppings" value="redpeppers">Red Peppers<br>
<input type="checkbox" name="toppings" value="pineapple">Pineapple<br>
<input type="checkbox" name="toppings" value="onion">Onion<br>
<input type="checkbox" name="toppings" value="tomato">Tomato<br><br>
 
<b>Select 1 FREE Appetizer</b>
<input type="radio" name="appetizer" value="Garlic Bread">Garlic Bread
<input type="radio" name="appetizer" value="Cheese Garlic Bread">Cheese Garlic Bread
<input type="radio" name="appetizer" value="Veg Soup">Veg Soup
<input type="radio" name="appetizer" value="Veg Sandwich">Veg Sandwich<br><br>
 
<b>Address</b><br>
<textarea name="address" rows=3 cols=40></textarea><br><br>
<b>Credit Card:</b><br>
<input type="radio" name="cardType" value="Visa">Visa
<input type="radio" name="cardType" value="MasterCard">MasterCard
<input type="radio" name="cardType" value="Amex">American Express
<br><br>
<b>Credit Card Number:</b> <input type="password" name="cardNum">
<b>Repeat Credit Card Number: </b><input type="password" name="cardNum"><br><br>
<input type="submit" name="submit" value="Order Pizza">
</form>
</body>
</html>

Environment Used

JDK version :1.6.0_30
Tomcat version : 7.0.50

To Download DisplayAllHeadersApp Project Click the below link

https://sites.google.com/site/javaee4321/servlets/DisplayAllHeadersApp.zip?attredirects=0&d=1

See also:

Servlets Tutorial

All Design Patterns Links