Question

即使我发现了几个类似的问题，我也无法创建我的第一个Hello World Servlet。我一直收到状态码404.

因此，在以下文件夹/home/smihai/apache-tomcat-7.0.52/webapps/HelloWorld/WEB-INF/中，我有一个 web.xml 文件和另一个文件夹＆＃34; classes＆＃34;有2个文件： HelloWorld.java 和 HelloWorld.class 。

web.xml文件包含：

<web-app>
    <servlet>
        <servlet-name>HelloWorld</servlet-name>
        <servlet-class>HelloWorld</servlet-class>
    </servlet>

    <servlet-mapping>
        <servlet-name>HelloWorld</servlet-name>
        <url-pattern>/HelloWorld</url-pattern>
    </servlet-mapping>
</web-app>

HelloWorld.java包含：

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>");
    }
}

我做错了什么？

Answer 1

您需要将HelloWorld.java类放入/移动到包中。
网址为：localhost:8080/HelloWorld/HelloWorld

文件夹结构：

enter image description here

HelloWorld.java：

package servlets;

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

    /**
     * Default constructor. 
     */
    public HelloWorld() {
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected 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>");
    }

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

}

Servlet的映射：

<servlet>
    <description></description>
    <display-name>HelloWorld</display-name>
    <servlet-name>HelloWorld</servlet-name>
    <servlet-class>servlets.HelloWorld</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>HelloWorld</servlet-name>
    <url-pattern>/HelloWorld</url-pattern>
  </servlet-mapping>

URL：

enter image description here

HTTP状态代码404 Java / Servlets

1 个答案:

文件夹结构：

HelloWorld.java：

Servlet的映射：

URL：