p2p.wrox.com Forums - HTTP STATUS 404 ERROR TOMCAT

Hi all,
I'm new to servlet to I'm testing my first servlet program but it is giving HTTP STATUS 404 error. The things which I have done are:
1> Installed java-> C:\Program Files\Java\jdk1.7.0
2> Installed Tomcat-> C:\apache-tomcat-7.0.23
3> When I type -> localhost:8080 in the browser it works fine.
4> Directory for the folder which I created-> C:\apache-tomcat-7.0.23\webapps\Hello
It contains a web.xml file and WEB-INF folder.
Inside WEB-INF, there is a folder named classes, which contains HelloServlet.class

The Souce code for my java file 'HelloServlet.java' is given below-

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

public class HelloServlet extends HttpServlet
{
public void doGet(HttpServletResponse response,HttpServletRequest request)throws ServletException,IOException
{
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("<html>");
out.println("<head>");
out.println("<title>Hello bhai</title>");
out.println("<head>");
out.println("<body>");
out.println("<h1>Hey bhagwan ho jaye bus</h1>");
out.println("</body>");
out.println("</html>");
}
}

web.xml file code-

<?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>HelloServlet</servlet-name>
<servlet-class>HelloServlet</servlet-class>
</servlet>

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

</web-app>

After reading few suggestions I tried by changing url to /HelloServlet.htm (or .html) but still I get the same error message.
************************************************** ****
HTTP Status 404 - /Hello/HelloServlet.html

type Status report

message /Hello/HelloServlet.html

description The requested resource (/Hello/HelloServlet.html) is not available.
Apache Tomcat/7.0.23
************************************************** ****Log file catalina.2011-12-11 is-
Dec 11, 2011 8:25:59 AM org.apache.catalina.core.AprLifecycleListener init
INFO: Loaded APR based Apache Tomcat Native library 1.1.22.
Dec 11, 2011 8:26:00 AM org.apache.catalina.core.AprLifecycleListener init
INFO: APR capabilities: IPv6 [false], sendfile [true], accept filters [false], random [true].
Dec 11, 2011 8:26:07 AM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["http-apr-8080"]
Dec 11, 2011 8:26:07 AM org.apache.coyote.AbstractProtocol init
INFO: Initializing ProtocolHandler ["ajp-apr-8009"]
Dec 11, 2011 8:26:07 AM org.apache.catalina.startup.Catalina load
INFO: Initialization processed in 9718 ms
Dec 11, 2011 8:26:07 AM org.apache.catalina.core.StandardService startInternal
INFO: Starting service Catalina
Dec 11, 2011 8:26:07 AM org.apache.catalina.core.StandardEngine startInternal
INFO: Starting Servlet Engine: Apache Tomcat/7.0.23
Dec 11, 2011 8:26:07 AM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory C:\apache-tomcat-7.0.23\webapps\docs
Dec 11, 2011 8:26:11 AM org.apache.catalina.util.SessionIdGenerator createSecureRandom
INFO: Creation of SecureRandom instance for session ID generation using [SHA1PRNG] took [1,313] milliseconds.
Dec 11, 2011 8:26:11 AM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory C:\apache-tomcat-7.0.23\webapps\examples
Dec 11, 2011 8:26:12 AM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory C:\apache-tomcat-7.0.23\webapps\Hello
Dec 11, 2011 8:26:13 AM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory C:\apache-tomcat-7.0.23\webapps\host-manager
Dec 11, 2011 8:26:13 AM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory C:\apache-tomcat-7.0.23\webapps\manager
Dec 11, 2011 8:26:13 AM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory C:\apache-tomcat-7.0.23\webapps\ROOT
Dec 11, 2011 8:26:13 AM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-apr-8080"]
Dec 11, 2011 8:26:13 AM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["ajp-apr-8009"]
Dec 11, 2011 8:26:14 AM org.apache.catalina.startup.Catalina start
INFO: Server startup in 6679 ms

Please help me out as soon as possible. I'll be very much thankful to you.[:)]

Regards-
Rahul