springMVC乱码问题

2023-09-27 19:49:34

1.首先先写一个表单

<%--
  Created by IntelliJ IDEA.
  User: 邬雨航
  Date: 2022/1/11
  Time: 23:51m
  To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
<%--post方式提交到后台EncodingController--%>
<form action="/e/t1" method="post">
    <input type="text" name="name">
    <input type="submit">
</form>
</body>
</html>

2.然后传到controller中（注意action的路径和method传达方式有没有错）

package com.kuang.controller;

import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.PostMapping;

import javax.servlet.http.HttpServletRequest;
import java.io.UnsupportedEncodingException;

/**
 * @author diao 2022/1/11
 */
@Controller
public class EncodingController {
    //在form页面提交数据后跳到这个Controller中，然后将输入的name传入msg返回到test页面上
    /*
    这里需要注意请求方式，@RequestMapping可以应用于所有
    * */
    @PostMapping("/e/t1")
    public String test1(String name, Model model, HttpServletRequest request) throws UnsupportedEncodingException {
        //乱码是java层面出错误
        request.setCharacterEncoding("utf-8");
        System.out.println(name);
        model.addAttribute("msg", name);
//        model.addAttribute("msg", name);
        //提交请求时，在后台将数据提交到test页面展示
        return "test1";
    }
}

1.第一种解决方式：

request.setCharacterEncoding("utf-8");

reponse.setCharacterEncoding("utf-8");

2.在web.xml中配置一个filter

    <filter>
        <filter-name>encoding</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>utf-8</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>encoding</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

这里注意一下/* ,因为你拦截的话，/对jsp并不起作用，而你乱码的情况是出现在前端页面上(Controller传前端输入的数据到jsp页面)，所以需要/*

3.第三种，大神自定义的一个Filter

/**
* 解决get和post请求 全部乱码的过滤器
*/
public class GenericEncodingFilter implements Filter {

   @Override
   public void destroy() {
  }

   @Override
   public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
       //处理response的字符编码
       HttpServletResponse myResponse=(HttpServletResponse) response;
       myResponse.setContentType("text/html;charset=UTF-8");

       // 转型为与协议相关对象
       HttpServletRequest httpServletRequest = (HttpServletRequest) request;
       // 对request包装增强
       HttpServletRequest myrequest = new MyRequest(httpServletRequest);
       chain.doFilter(myrequest, response);
  }

   @Override
   public void init(FilterConfig filterConfig) throws ServletException {
  }

}

//自定义request对象，HttpServletRequest的包装类
class MyRequest extends HttpServletRequestWrapper {

   private HttpServletRequest request;
   //是否编码的标记
   private boolean hasEncode;
   //定义一个可以传入HttpServletRequest对象的构造函数，以便对其进行装饰
   public MyRequest(HttpServletRequest request) {
       super(request);// super必须写
       this.request = request;
  }

   // 对需要增强方法 进行覆盖
   @Override
   public Map getParameterMap() {
       // 先获得请求方式
       String method = request.getMethod();
       if (method.equalsIgnoreCase("post")) {
           // post请求
           try {
               // 处理post乱码
               request.setCharacterEncoding("utf-8");
               return request.getParameterMap();
          } catch (UnsupportedEncodingException e) {
               e.printStackTrace();
          }
      } else if (method.equalsIgnoreCase("get")) {
           // get请求
           Map<String, String[]> parameterMap = request.getParameterMap();
           if (!hasEncode) { // 确保get手动编码逻辑只运行一次
               for (String parameterName : parameterMap.keySet()) {
                   String[] values = parameterMap.get(parameterName);
                   if (values != null) {
                       for (int i = 0; i < values.length; i++) {
                           try {
                               // 处理get乱码
                               values[i] = new String(values[i]
                                      .getBytes("ISO-8859-1"), "utf-8");
                          } catch (UnsupportedEncodingException e) {
                               e.printStackTrace();
                          }
                      }
                  }
              }
               hasEncode = true;
          }
           return parameterMap;
      }
       return super.getParameterMap();
  }

   //取一个值
   @Override
   public String getParameter(String name) {
       Map<String, String[]> parameterMap = getParameterMap();
       String[] values = parameterMap.get(name);
       if (values == null) {
           return null;
      }
       return values[0]; // 取回参数的第一个值
  }

   //取所有值
   @Override
   public String[] getParameterValues(String name) {
       Map<String, String[]> parameterMap = getParameterMap();
       String[] values = parameterMap.get(name);
       return values;
  }
}

然后在web.xml中配置上去即可;

码农公寓

1.第一种解决方式：

2.在web.xml中配置一个filter

3.第三种，大神自定义的一个Filter

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