Java Web解决解析乱码和响应乱码

package cn.edu.aynu.rjxy.servlet;

import java.io.IOException;
import java.io.PrintWriter;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class AServlet extends HttpServlet {
    /*get方式请求时调用的方法
     * 什么是get请求?
     * 在地址栏输入用户名和密码、超链接、直接在method里面写上get
     * get没有请求体 无法设置请求体
     * 首先需要获取到username和psw
     * 然后把字符串回退为字节数组
     * 使用ISO-8859-1编码方式解码
     * 把字节数组重新组装成字符串,使用UTF-8编码方式
     * 
     */
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        request.setCharacterEncoding("UTF-8");
        //根据参数名获取参数值
        String username = request.getParameter("username");
        String  psw = request.getParameter("psw");
        
        //使用ISO-8859-1把username的值回退成字节数组
        byte[] b = username.getBytes("ISO-8859-1");
        //使用UTF-8把字节数组重新解码
        username = new String(b,"UTF-8");
        //响应输出流的编码方式是UTF-8 客户端、浏览器解码方式也为UTF-8
        response.setContentType("text/html;charset=utf-8");
        //输入到界面上
        response.getWriter().print("username="+username);
        response.getWriter().print("psw="+psw);
        //输入到控制台上
        System.out.println("username="+username);
        System.out.println("psw="+psw);
    }

    //post方式请求调用的方法
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        /*post请求的解码处理   乱码出现的根源是:编码方式和解码方式不一致。
         * tomcat服务器默认的解码方式是ISO-8859-1不支持中文。由于post请求
         * 有请求体,请求参数是放在请求体中的,设置请求体的解码方式,需要调用
         * 方法request.setCharacterEncoding("UTF-8");支持中文
         */
        request.setCharacterEncoding("UTF-8");
        //根据参数名获取参数值
        String username = request.getParameter("username");
        String  psw = request.getParameter("psw");
        //根据参数名获取多个参数值
String[] hobby
= request.getParameterValues("hobby"); //数组的遍历
for (int i = 0; i < hobby.length; i++) { System.out.println(hobby[i]); } //响应输出流的编码方式是UTF-8 客户端、浏览器解码方式也为UTF-8 response.setContentType("text/html;charset=utf-8"); //输入到界面上 response.getWriter().print("username="+username); response.getWriter().print("psw="+psw); //输入到控制台上 System.out.println("username="+username); System.out.println("psw="+psw); } }

AServlet.java

 a.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'a.jsp' starting page</title>
    
    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">    
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">
    <!--
    <link rel="stylesheet" type="text/css" href="styles.css">
    -->

  </head>
  
  <body>
   <form action = "/day9/AServlet" method = "post">
           用户名:<input type = "text" name = "username"/><br/>
           密     码:<input type = "password" name = "psw"/><br/>
           爱好:<input type = "checkbox" name = "hobby" value ="Swimming">游泳
                <input type = "checkbox" name = "hobby" value ="Sing">唱歌
                <input type = "checkbox" name = "hobby" value ="Run">跑步
                <input type = "checkbox" name = "hobby" value ="Read">阅读<br>
           <input type = "submit" value="提交">
   </form>
   <hr>
   <a href="/day9/AServlet?username=李四&psw=123">get方式请求</a>
  </body>
</html>
原文地址:https://www.cnblogs.com/kangyaping/p/5910214.html