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Request-获取请求参数通用方式介绍、获取请求参数通用方式演示

时间:2023-02-07 20:55:57浏览次数:40  
标签:请求 System 获取 参数 println out String

Request-获取请求参数通用方式介绍

  1. 获取请求参数通用方式:不论get还是post请求方式都可以使用下列方法来获取请求参数

    1. String getParameter(String name):根据参数名称获取参数值 username=zs&password=123

    2. String[] getParameterValues(String name):根据参数名称获取参数值的数组 hobby=xx&hobby=game

    3. Enumeration<String> getParameterNames():获取所有请求的参数名称

    4. Map<String,String[]> getParameterMap():获取所有参数的map集合

Request-获取请求参数通用方式演示

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>注册页面</title>
</head>
<body>

    <form action="/day14/requestDemo7" method="post">
        <input type="text" placeholder="请输入用户名" name="username"><br>
        <input type="text" placeholder="请输入密码" name="password"><br>

        <input type="checkbox" name="hobby" value="game">游戏
        <input type="checkbox" name="hobby" value="study">学习
        <br>

        <input type="submit" value="注册">

    </form>

</body>
</html>
package com.example.request;

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.BufferedReader;
import java.io.IOException;
import java.util.Enumeration;
import java.util.Map;
import java.util.Set;

@WebServlet("/requestDemo6")
public class RequestDemo6 extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //post 获取请求参数

        //根据参数名称获取参数值
        String username = request.getParameter("username");
       /* System.out.println("post");
        System.out.println(username);*/

       //根据参数名称获取参数值的数组
        String[] hobbies = request.getParameterValues("hobby");
        /*for (String hobby : hobbies) {
            System.out.println(hobby);
        }*/

        //获取所有请求的参数名称

        Enumeration<String> parameterNames = request.getParameterNames();
        /*while(parameterNames.hasMoreElements()){
            String name = parameterNames.nextElement();
            System.out.println(name);
            String value = request.getParameter(name);
            System.out.println(value);
            System.out.println("----------------");
        }*/

        // 获取所有参数的map集合
        Map<String, String[]> parameterMap = request.getParameterMap();
        //遍历
        Set<String> keyset = parameterMap.keySet();
        for (String name : keyset) {
            
            //获取键获取值
            String[] values = parameterMap.get(name);
            System.out.println(name);
            for (String value : values) {
                System.out.println(value);
            }

            System.out.println("-----------------");
        }


    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //get 获取请求参数
/*
        //根据参数名称获取参数值
        String username = request.getParameter("username");
        System.out.println("get");
        System.out.println(username);*/

        this.doPost(request,response);
    }
}

标签:请求,System,获取,参数,println,out,String
From: https://www.cnblogs.com/wsfj/p/17099782.html

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