request (请求转发)

index.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>登录</title>
</head>
<body>

<h1>登录</h1>

<div>
    <%--这里表单的意思是：以post方式提交表单，提交到login请求中--%>
    <from action="${pageContext.request.getContextPath()}/login" method="post">
        用户名：<input type="text" name="username"><br>
        密 码：<input type="text" name="password"><br>
        爱 好：
        <input type="checkbox" name="hobbys" value="女孩">女孩
        <input type="checkbox" name="hobbys" value="代码">代码
        <input type="checkbox" name="hobbys" value="唱歌">唱歌
        <input type="checkbox" name="hobbys" value="电影">电影

        <br>
        <input type="submit">
    </from>


</div>

</body>
</html>

实现类：LoginServlet

package com.king.servlet;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Arrays;

public class LoginServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        String username = req.getParameter("username");
        String password = req.getParameter("password");
        String[] hobbys = req.getParameterValues("hobbys");

        System.out.println("==================================");
        System.out.println(username);
        System.out.println(password);
        System.out.println(Arrays.toString(hobbys));
        System.out.println("==================================");

        System.out.println(req.getContextPath());

        //通过请求转发
        req.getRequestDispatcher("/success.jsp").forward(req,resp);


    }


    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        doGet(req, resp);
    }
}

转发成功页面

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<h1>登陆成功</h1>

</body>
</html>

配置web

<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee
                      http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
         version="4.0"
         metadata-complete="true">

    <servlet>
        <servlet-name>login</servlet-name>
        <servlet-class>com.king.servlet.LoginServlet</servlet-class>
    </servlet>
    <servlet-mapping>
        <servlet-name>login</servlet-name>
        <url-pattern>/login</url-pattern>
    </servlet-mapping>

</web-app>