HttpServletRequest
HttpServletRequest represents the client's request. The user accesses the server through the Http protocol. All information in the HTTP request will be encapsulated in HttpServletRequest. Through this HttpServletRequest method, all the information of the client can be obtained.
1. Get the parameters passed by the front end and request forwarding
package com.weng.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 {
req.setCharacterEncoding("utf-8");
resp.setCharacterEncoding("utf-8");
String username = req.getParameter("username");
String password = req.getParameter("password");
String[] hobbys = req.getParameterValues("hobbys");
System.out.println("=============================");
//后台接收中文乱码问题
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
//这里的 / 代表当前的web应用
req.getRequestDispatcher("/request_war/success.jsp").forward(req,resp);
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doGet(req, resp);
}
}
<?xml version="1.0" encoding="UTF-8"?>
<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>LoginServlet</servlet-name>
<servlet-class>com.weng.servlet.LoginServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>LoginServlet</servlet-name>
<url-pattern>/login</url-pattern>
</servlet-mapping>
</web-app>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>登录</title>
</head>
<body>
<h1>登录</h1>
<div>
<%--这里表单表示的意思:以post方式提交表单，提交到我们的Login请求--%>
<form action="${pageContext.request.contextPath}/login" method="post">
用户名: <input type="text" name="username"> <br>
密码:<input type="password" 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">
</form>
</div>
</body>
</html>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>Title</title>
</head>
<body>
<h1>登录成功</h1>
</body>
</html>