如何编写hello world servlet示例 [英] how to write hello world servlet Example

问题描述

javaclass

javaclass

package com.example;

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

// Extend HttpServlet class
public class Helloworld extends HttpServlet {
    private String message;

    public void init() throws ServletException {
        // Do required initialization
        message = "Hello World";
    }

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        // Set response content type
        response.setContentType("text/html");
        // Actual logic goes here.
        PrintWriter out = response.getWriter();
        out.println("<h1>" + message + "</h1>");
    }

    public void destroy() {
        // do nothing.
    }
}

web.xml

<servlet>
        <servlet-name>HelloForm</servlet-name>
        <servlet-class>HelloForm</servlet-class>
    </servlet>

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

Give is code但我运行项目没有输出来404页面出现错误。我们还需要为servlet创建Jsp页面吗？我是Servlet的新手请帮助如何编写hello world is Servlet。

Give is code But i run the Project There is no Output comes 404 Error is comes in web Page . we need create Jsp Page also for servlet? I am really new in Servlet Please help how to write hello world is Servlet .

推荐答案

你已经创建了这样的servlet类： / p>

You have created servlet class like this:

public class Helloworld extends HttpServlet

但是在web.xml中你有这样的映射：

But in web.xml you have mapping like this:

<servlet-class>HelloForm</servlet-class>

您需要具有相同的名称，因此您收到404错误。将您的servlet名称更改为 HelloForm 或将< servlet-class> 更改为 HelloWorld < web.xml中的/ code>

You need to have same name, so you're getting 404 error. Change either your servlet name to HelloForm or change <servlet-class> to HelloWorldin web.xml

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