Servlet Hello World,Helloworld Servlet Example,Java Servlet Hello World Example

Writing Servlet Hello World

We should start understanding the servlets from the beginning. Lets start by making one program which will just print the "Hello World" on the browser. Each time the user visits this page it will display "Hello World" to the user.

As we know that the our servlet extends the HttpServlet and overrides the doGet() method which it inherits from the HttpServlet class. The server invokes doGet() method whenever web server recieves the GET request from the servlet. The doGet() method takes two arguments first is HttpServletRequest object and the second one is HttpServletResponse object and this method throws the ServletException.

Whenever the user sends the request to the server then server generates two obects, first is HttpServletRequest object and the second one is HttpServletResponse object. HttpServletRequest object represents the client's request and the HttpServletResponse represents the servlet's response.

Inside the doGet(() method our servlet has first used the setContentType() method of the response object which sets the content type of the response to text/html. It is the standard MIME content type for the Html pages. After that it has used the method getWriter() of the response object to retrieve a PrintWriter object. To display the output on the browser we use the println() method of the PrintWriter class.

The code the program is given below:


import java.io.*;

import javax.servlet.*;

import javax.servlet.http.*;



public class HelloWorld extends HttpServlet{ 

  public void doGet(HttpServletRequest request, HttpServletResponse response)

                                      
    throws ServletException,IOException{

    response.setContentType("text/html");

    PrintWriter pw = response.getWriter();

    pw.println("<html>");

    pw.println("<head><title>Hello World</title></title>");

    pw.println("<body>");

    pw.println("<h1>Hello World</h1>");

    pw.println("</body></html>");

  }

}

web.xml file for this program:


<?xml version="1.0" encoding="ISO-8859-1"?>

<!--<!DOCTYPE web-app

 PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"

 "http://java.sun.com/dtd/web-app_2_3.dtd"> -->



<web-app>

 <servlet>

  <servlet-name>Hello</servlet-name>

  <servlet-class>HelloWorld</servlet-class>

 </servlet>

 <servlet-mapping>

 <servlet-name>Hello</servlet-name>

 <url-pattern>/HelloWorld</url-pattern>

 </servlet-mapping>

</web-app>

The output of the program is given below:

Current Comments

19 comments so far (post your own) View All Comments Latest 10 Comments:

sir
i have small problem,where can i run the servlets program i have Mysql&netbeans i just make a servlet now what i hav to doto run . i am fresher & learing java from ur site this site is enough to learn java.sequentialy tell me how to run servlets programs in html and jsp also how to run give me thats code deatils

rgds
SWATHI.S

Posted by SWATHI.S on Monday, 12.15.08 @ 00:39am | #82763

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how to run servlet programes with database connection

Posted by swathi on Monday, 12.15.08 @ 00:34am | #82762

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i dont how to set the environment variable path to servlet.jar.please help me
thank you...

Posted by peter on Sunday, 10.5.08 @ 00:08am | #80900

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Posted by sudhakar.s on Friday, 09.19.08 @ 13:25pm | #80486

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firstly i want to tell you we can create servlet by two way:--
1- By extending GenericServlet class
2- By extending HttpServlet class
in 1 we will override service method
in 2 we override processRequest method

Posted by dinesh on Friday, 08.1.08 @ 22:48pm | #70365

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hai

I have wrote in one program using java servlet,but i don't know familiar to run this servlet,how can i run? can u help me?........

thanks in advance

Posted by kala on Thursday, 06.19.08 @ 11:29am | #63834

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hello,
sir,
can u explain how to run servlets,
with examples

Posted by shiva on Thursday, 12.20.07 @ 17:14pm | #43114

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someone said its better late than never..roseindia..u r doing an awesome job to millions of ppl around d world..thanks a lot.

Posted by dj on Wednesday, 12.5.07 @ 05:20am | #41317

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sir
i have small problem,where can i run the servlets program i have tomcat & ecllips 3.1 and i know working on ecllips, i just make a servlet now what i hav to doto run . i am fresher & learing java from ur site this site is enough to learn java.sequentialy tell me how to run servlets programs on ecllips

rgds
rajesh