HTTP Status 500 - Error instantiating servlet class java.reg.pkg.Hello

Question

I am trying to execute a servlet program in eclipse, but i am getting an HTTP status 500 error.

Please find my directory structure:

Practice_servlet | Java Resources | src | javs.reg.pkg | Hello.java

My web.xml is:

<?xml version="1.0" encoding="UTF-8"?>
<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_2_5.xsd" id="WebApp_ID" version="2.5">
  <display-name>Practice1_servlet</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  <servlet>
      <servlet-name>Hello1</servlet-name>
    <servlet-class>java.reg.pkg.Hello</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>Hello1</servlet-name>
    <url-pattern>/hello</url-pattern>
  </servlet-mapping>
</web-app>

My hello.java program is:

package java.reg.pkg;

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;

/**
 * Servlet implementation class Hello
 */
public class Hello extends HttpServlet {
    private static final long serialVersionUID = 1L;

    /**
     * @see HttpServlet#HttpServlet()
     */
    public Hello() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("type/html");
        PrintWriter out = response.getWriter();
        out.println("Hello World");
        // TODO Auto-generated method stub
    }

}

Any idea of what the problem could be ?

Stack trace for the above program:

HTTP Status 500 - Error instantiating servlet class java.reg.pkg.Hello

type Exception report

message Error instantiating servlet class java.reg.pkg.Hello

description The server encountered an internal error that prevented it from fulfilling this request.

exception

javax.servlet.ServletException: Error instantiating servlet class java.reg.pkg.Hello org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501) org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98) org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950) org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408) org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1040) org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607) org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:313) java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) java.lang.Thread.run(Unknown Source)

root cause

java.lang.ClassNotFoundException: java.reg.pkg.Hello org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1718) org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1569) org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:501) org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98) org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950) org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:408) org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1040) org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:607) org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:313) java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) java.lang.Thread.run(Unknown Source)

note The full stack trace of the root cause is available in the Apache Tomcat/7.0.52 logs.

I am using Apache Tomcat/7.0.52.

I don't get 500 if I copy and paste your code in my Eclipse... — Diferdin, Apr 07 '14 at 13:08
i tried in other pc and i didn't get 500 error .But why my machine is giving 500 error? — user3090870, Apr 08 '14 at 04:20

score 0 · Answer 1 · answered Nov 01 '15 at 16:02

0

Try cleaning the project and run. If you are using eclipse Project -> Clean

answered Nov 01 '15 at 16:02

saravan kumar

58
6

score -2 · Answer 2 · answered Apr 07 '14 at 13:10

-2

I think there is a wrong name there. Your servlet is called Hello and is in java.reg.pkg, while the stack trace says it is instructed to load a servlet called SampleHello within the java.sample.pkg package.

The web.xml you provided has no trace of the latter servlet, hence the ClassNotFoundException error...

answered Apr 07 '14 at 13:10

Diferdin

1,252
1
14
30

1

Sorry i posted wrong stack trace yesterday.Please find the correct stack trace above. – user3090870 Apr 08 '14 at 04:19

HTTP Status 500 - Error instantiating servlet class java.reg.pkg.Hello

2 Answers2