解决全站字符乱码（POST和GET中文编码问题）

1　说明

乱码问题：

• 获取请求参数中的乱码问题；
  •  POST请求：request.setCharacterEncoding(“utf-8”)；
  •  GET请求：new String(request.getParameter(“xxx”).getBytes(“iso-8859-1”), “utf-8”)；
    • Tomcat 8.5.20、Tomcat 9.0.0.M26 默认编码都是utf-8,所有不出现GET请求乱码问题，所以不需处理
• 响应的乱码问题：response.setContextType(“text/html;charset=utf-8”)。

2、当GET请求出现乱码问题时（默认编码为ISO-8859-1时），可采用以下方法解决：

 1 package web.filter;
 2 
 3 import javax.servlet.*;
 4 import javax.servlet.annotation.WebFilter;
 5 import javax.servlet.http.HttpServletRequest;
 6 import java.io.IOException;
 7 
 8 @WebFilter(filterName = "EncodingFilter",urlPatterns = "/*") 9 public class EncodingFilter implements Filter { 10 public void destroy() { } 11 public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws ServletException, IOException { 12 //处理post请求编码问题 13 req.setCharacterEncoding("utf-8"); 14 15 HttpServletRequest request = (HttpServletRequest) req; 16 //处理get请求的编码问题 17 if ( request.getMethod().equals("GET")){ 18 EncodingRequest er = new EncodingRequest(request); 19  chain.doFilter(er, resp); 20 } else { 21  chain.doFilter(req,resp); 22  } 23  } 24 public void init(FilterConfig config) throws ServletException { } 25 }

 1 package web.filter;
 2 
 3 import javax.servlet.http.*;
 4 import java.io.UnsupportedEncodingException;
 5 
 6 /**
 7  * 装饰request
 8  */
 9 public class EncodingRequest extends HttpServletRequestWrapper{
10     private HttpServletRequest request ;
11     public EncodingRequest(HttpServletRequest req) { 12 super(req); 13 this.request = req; 14  } 15 public String getParameter(String s) { 16 String value = request.getParameter("s"); 17 //处理编码问题 18 try { 19 value = new String(value.getBytes("iso-8859-1"),"utf-8"); 20 } catch (UnsupportedEncodingException e) { 21 throw new RuntimeException(e); 22  } 23 return value; 24  } 25 }

 1 package web.servlet;
 2 
 3 import javax.servlet.ServletException;
 4 import javax.servlet.annotation.WebServlet;
 5 import javax.servlet.http.HttpServlet;
 6 import javax.servlet.http.HttpServletRequest;
 7 import javax.servlet.http.HttpServletResponse; 8 import java.io.IOException; 9 10 @WebServlet(name = "AServlet",urlPatterns = "/AServlet") 11 public class AServlet extends HttpServlet { 12 protected void doPost(HttpServletRequest request, HttpServletResponse response) 13 throws ServletException, IOException { 14 response.setContentType("text/html;charset=utf-8"); 15 String username = request.getParameter("username"); 16  response.getWriter().println(username); 17  } 18 19 protected void doGet(HttpServletRequest request, HttpServletResponse response) 20 throws ServletException, IOException { 21 response.setContentType("text/html;charset=utf-8"); 22 String username = request.getParameter("username"); 23  response.getWriter().println(username); 24  } 25 }

 1 <%@ page contentType="text/html;charset=UTF-8" language="java" %>
 2 <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
 3 
 4   
 5     
 6   
 7   
 8   点击这里
 9   

10     用户名：
11     
12   
13   
14 

3、当只有POST请求出现乱码问题时（服务器默认编码为UTF-8时），可采用以下方法解决：

 1 @WebFilter(filterName = "EncodingFilter",urlPatterns = "/*")
 2 public class EncodingFilter implements Filter {
 3     public void destroy() { }
 4     public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain) throws ServletException, IOException {
 5         //处理post请求编码问题
 6         req.setCharacterEncoding("utf-8");
 7  chain.doFilter(req,resp); 8  } 9 public void init(FilterConfig config) throws ServletException {} 10 }

 1 @WebServlet(name = "AServlet",urlPatterns = "/AServlet")
 2 public class AServlet extends HttpServlet {
 3     protected void doPost(HttpServletRequest request, HttpServletResponse response)
 4             throws ServletException, IOException {
 5         response.setContentType("text/html;charset=utf-8");
 6         String username = request.getParameter("username"); 7  response.getWriter().println(username); 8  } 9 10 protected void doGet(HttpServletRequest request, HttpServletResponse response) 11 throws ServletException, IOException { 12 response.setContentType("text/html;charset=utf-8"); 13 String username = request.getParameter("username"); 14  response.getWriter().println(username); 15  } 16 }

 

转载于:https://www.cnblogs.com/gdwkong/p/7623637.html