HTTP Status 404 - The requested resource is not available Java Servlet

Question

I had Created Dynamic Project eclipse and added package in java resource then added a Servlet in it. Here is my class where i simply getting a hello world out in doGet Method. package com.helloworldserverlet.serverlet;

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

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

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

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        response.getWriter().append("Served at: ").append(request.getContextPath());
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        doGet(request, response);
    }

}

Now while I try to run it i will gives me error 404 that require resources are not found. Do i have to defined the servlet in my web.xml .Currently my web.xml is

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
  <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>

Thanks in Advance

Yes you need to configure the servlet in web.xml – Sunil Dabburi May 20 '16 at 16:53 — Sunil Dabburi, May 20 '16 at 16:53
No, the @WebServlet annotation should be enough. – stdunbar May 20 '16 at 17:21 — stdunbar, May 20 '16 at 17:21

Minjun Yu · Answer 1 · 2016-05-20T17:54:33.873

while I try to run it i will gives me error 404

There could be lot of reasons, the most common ones are:

Your application context path is "app" and you run it using
http://localhost:8080/HelloWorld
the correct way to do is
http://localhost:8080/app/HelloWorld
Your application context path is "/" and you run it using
http://localhost:8080/app/HelloWorld
the correct way to do is
http://localhost:8080/HelloWorld
You simply spelled the servlet path wrong, the path mapping is case-sensitive.

Note:
"app" can be any name you specified, I used it just for demo. Please provide us with more info such as your complete expanded project tree and your browser location bar where you have put the url.

score 0 · Answer 2 · edited May 20 '16 at 19:37

You need to set more configuration in web.xml. I have a sample from Spring, and in my configuration I have:

<web-app xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
      http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
version="2.5">

    ...

    <servlet>
        <servlet-name>mvc-dispatcher</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
        <servlet-name>mvc-dispatcher</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>

</web-app>

Shouldn't be too different. I think you should change org.springframework.web.servlet.DispatcherServlet for com.helloworldserverlet.serverlet.HelloWorld, or whatever your Servlet class is.

No, the OP has the @WebServlet annotation - it should work fine. — stdunbar, May 20 '16 at 17:21

HTTP Status 404 - The requested resource is not available Java Servlet

2 Answers2