使用Tomcat服务器运行Servlet类时出现HTTP Status 400错误

Question

I am totally new to writing servlets. I have created a simple HelloWorld program, but while running the application I'm getting the following error:

HTTP Status 404 - /HelloWorld/HelloWorld

type Status report

message /HelloWorld/HelloWorld

description: The requested resource is not available.

Below is my code:

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

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


@WebServlet("/HelloWorld")
public class HelloWorld extends HttpServlet {
    private static final long serialVersionUID = 1L;           

    public HelloWorld() {
        super();  
    }    

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        PrintWriter out=response.getWriter();
        out.println("Hello World");
    }
}

And my web.xml

<display-name>HelloWorld</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>
</web-app>

I'm using Tomcat version:7.0 and my IDE is Eclipse Luna. Why is this error being thrown?

Answer 1

your_war_file_name/HelloWorld... You can find the war file name under webapps folder in Tomcat directory. Here I just recreated the same. My war file name is website.war. It works for me. The url is http://localhost:8090/website/developer . I got the response "Hello World" .... :)

package com.test.developer;

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 Test extends HttpServlet{

    private static final long serialVersionUID = 1L;


    public Test() {
        super();

    }


    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        System.out.println("Inside servelt");
        PrintWriter out=response.getWriter();
        out.println("Hello World");
    }
}

and 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" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0">
  <display-name>website</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>developer</servlet-name>
  <servlet-class>com.test.developer.Test</servlet-class>
  </servlet>
  <servlet-mapping>
  <servlet-name>developer</servlet-name>
  <url-pattern>/developer</url-pattern>
  </servlet-mapping>
</web-app>