requset获取post提交的请求参数

1.请求体的内容通常是通过post来提交的，格式是

username=zhansan&password=123&hobby=football||&hobby=basketball

key--------------------------------value

username [zhangsan]

password [123]

hobby [football,basketball]

2.定义和用法

// 1.获取单个表单中的value值

        String usernam = request.getParameter("usernam");

        String password = request.getParameter("password");

// 2.获取多个表单的value值

        String[] parameterValues = request.getParameterValues("hobby");

        System.out.print("hobby.values:");

// 3.获得所有参数的name

            Enumeration<String> parameterNames = request.getParameterNames();

            for (String string2 : parameterValues) {

                System.out.println(parameterNames.nextElement());

            }

// 4.将获得的所有参数封装到一个Map<String,String[]>
    Map<String, String[]> parameterMap = request.getParameterMap();
        for (Map.Entry<String, String[]> entry : parameterMap.entrySet()) {
            System.out.println(entry.getKey());
            for (String string : entry.getValue()) {
                System.out.println(string);
            }
            System.out.println("----------------");
        }

3.实例结果

4.完整代码

package com.hdh.requesd;

import java.io.IOException;

import java.util.Enumeration;

import java.util.Map;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

public class ContentServlet extends HttpServlet {

    protected void doGet(HttpServletRequest request, HttpServletResponse response)

            throws ServletException, IOException {

        // 1.获取单个表单中的value值

        String usernam = request.getParameter("usernam");

        String password = request.getParameter("password");

        System.out.println("usernam.value:" + usernam);

        System.out.println("password.value:" + password);

        // 2.获取多个表单的value值

        String[] parameterValues = request.getParameterValues("hobby");

        System.out.print("hobby.values:");

        for (String string : parameterValues) {

            System.err.print(string + "  ");

        }

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

        // 3.获得所有参数的name

        Enumeration<String> parameterNames = request.getParameterNames();

        for (String string2 : parameterValues) {

            System.out.println(parameterNames.nextElement());

        }

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

        // 4.将获得的所有参数封装到一个Map<String,String[]>中

        Map<String, String[]> parameterMap = request.getParameterMap();

        for (Map.Entry<String, String[]> entry : parameterMap.entrySet()) {

            System.out.println(entry.getKey());

            for (String string : entry.getValue()) {

                System.out.println(string);

            }

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

        }

    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response)

            throws ServletException, IOException {

        doGet(request, response);

    }

}

form.html

<!DOCTYPE html>

<html>

<head>

<meta charset="UTF-8">

<title>Insert title here</title>

</head>

<body>

    <hr>

    <form action="/WEB15/content" method="post">

    姓名：<input type="text" name="username"><br>

    密码：<input type="password" name="password"><br>

    <input type="checkbox" name="hobby" value="zq">足球

    <input type="checkbox" name="hobby" value="lq">篮球

    <input type="checkbox" name="hobby" value="ppq">乒乓球

    <input type="submit" value="提交">

    </form>

</body>

</html>