HttpServletRequest对象——获取请求参数

一、项目结构

1、表单

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>get请求</title>
</head>
<body>
    <form action="parameter" method="get">
        <h3>用户登录</h3>
        <p>用户名:<input type="text" name="username"></p>
        <p>密 码:<input type="text" name="password"> </p>
        <input type="submit" value="登录">
    </form>
</body>
</html>

2、servlet

package net.test.servlet;

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

@WebServlet(name="helloServlet",urlPatterns="/parameter")  //1、配置servlet
public class HelloServlet extends HttpServlet {  //2、继承HttpServlet

    //3、重写doPost方法
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
    }

    //3、重写doGet方法
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //获取请求参数
        String username = req.getParameter("username");
        String password = req.getParameter("password");
        System.out.println("用户名:"+username);
        System.out.println("密码:"+password);
    }
}

3、运行

访问浏览器:
HttpServletRequest对象——获取请求参数
发起get请求
(输入用户名、密码,点击登录)
HttpServletRequest对象——获取请求参数
运行结果:
HttpServletRequest对象——获取请求参数
HttpServletRequest对象——获取请求参数