Response响应的中文乱码问题

乱码呈现 

乱码解释

乱码解决

初步解决 

改进版 

精华版

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在这里介绍了Request请求参数中文乱码问题，以及Response响应，下面我们介绍Response响应的中文乱码问题

乱码呈现 

先来一个资源路径，不需要手动关闭流，因为响应结束就会自动关闭

字节输出流ServletOutputStream outputStream = response.getOutputStream()和字符输出流PrintWriter writer = response.getWriter()原理是一样的，这里用字符流举例。

IE浏览器访问

中文出现了乱码

乱码解释

因为Response对象时tomcat创建的，tomcat默认使用的是ISO-8859-1字符集，而IE浏览器默认使用的是GB2312字符集,也就是GBK字符集解码，2者的字符集不一样，所以会出现乱码

乱码解决

初步解决 

既然明白了乱码出现的原因，那么我们的解决办法就是在Response写入流对象的时候，就修改其编码字符集。

response.setCharacterEncoding("GBK");

现在我们把Response字符集改为BGK

package com.lingaolu.response;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.*;
import java.io.IOException;
import java.io.PrintWriter;

/**
 * @author 林高禄
 * @create 2020-07-10-22:41
 */
@WebServlet("/responseDemo5")
public class ResponseDemo5 extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setCharacterEncoding("GBK");
        PrintWriter writer = response.getWriter();
        writer.println("Java");
        writer.println("林大帅");

    }
}

浏览器访问

改进版 

现在我们有一款浏览器的默认解码字符集为UTF-8,那么好的，我们就把Response字符集改为UTF-8，但是这时候，IE浏览器访问是不是乱码了，所以呢我们还得该告诉浏览器使用什么字符集编码。

response.setHeader("Content-Type","text/html;charset=utf-8");

package com.lingaolu.response;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.*;
import java.io.IOException;
import java.io.PrintWriter;

/**
 * @author 林高禄
 * @create 2020-07-10-22:41
 */
@WebServlet("/responseDemo5")
public class ResponseDemo5 extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setCharacterEncoding("utf-8");
        response.setHeader("Content-Type","text/html;charset=utf-8");
        PrintWriter writer = response.getWriter();
        writer.println("Java");
        writer.println("林大帅");

    }
}

 

谷歌浏览器访问

IE浏览器访问

再看IE浏览器的解码字符集，变成了utf-8

既然有了response.setHeader("Content-Type","text/html;charset=utf-8");

那么response.setCharacterEncoding("utf-8")就不需要了

因为response.setHeader("Content-Type","text/html;charset=utf-8")已经把response的字符集改为了utf-8

我们删掉response.setCharacterEncoding("utf-8")

package com.lingaolu.response;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.*;
import java.io.IOException;
import java.io.PrintWriter;

/**
 * @author 林高禄
 * @create 2020-07-10-22:41
 */
@WebServlet("/responseDemo5")
public class ResponseDemo5 extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setHeader("Content-Type","text/html;charset=utf-8");
        PrintWriter writer = response.getWriter();
        writer.println("Java");
        writer.println("林大帅");

    }
}

重启访问浏览器

精华版

既然response.setHeader("Content-Type","text/html;charset=utf-8")中，Content-Type是唯一的，那么response就提供了一个更简便的方法

response.setContentType("text/html;charset=utf-8");

我们代码调整下，输出也加多了几个汉子

package com.lingaolu.response;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.*;
import java.io.IOException;
import java.io.PrintWriter;

/**
 * @author 林高禄
 * @create 2020-07-10-22:41
 */
@WebServlet("/responseDemo5")
public class ResponseDemo5 extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        response.setContentType("text/html;charset=utf-8");
        PrintWriter writer = response.getWriter();
        writer.println("Java");
        writer.println("林大帅真帅");

    }
}

重启访问

这就解决了response相应中文乱码问题

另外字节输出流ServletOutputStream outputStream = response.getOutputStream()解决中文乱码问题和字符输出流PrintWriter writer = response.getWriter()是一样的。