如何使用过滤器处理中文乱码

若是浏览器提交数据给Servlet的时候含中文参数，那么在Servlet中就要处理中文乱码。若是有多个Servlet都要同时接收中文参数，那么在Servlet中处理中文乱码就比较麻烦。html

解决办法：使用过滤器处理中文乱码。java

处理post请求的乱码web

index.jsp代码浏览器

<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>Insert title here</title>
</head>
<body>
  <form action="${pageContext.request.contextPath }/AddUserServlet" method="post"> 用户名:<input type="text" name="userName" /><br>
    <input type="submit" value="提交" />
  </form>
  <hr>
  <form action="${pageContext.request.contextPath }/AddProductServlet" method="post"> 产品名:<input type="text" name="productName" /><br>
    <input type="submit" value="提交" />
  </form>

</body>
</html>

AddUserServlet.java类代码（Servlet 业务处理）jsp

import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; /** * Servlet implementation class AddUserServlet */ @WebServlet("/AddUserServlet") public class AddUserServlet extends HttpServlet { protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //获取文本框输入参数
        String userName=request.getParameter("userName"); System.out.println("userName="+userName); } /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub
 doGet(request, response); } }

AddProductServlet.java类代码（Servlet 业务处理）ide

import java.io.IOException; import javax.servlet.ServletException; import javax.servlet.annotation.WebServlet; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; /** * Servlet implementation class AddProductServlet */ @WebServlet("/AddProductServlet") public class AddProductServlet extends HttpServlet { protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //获取文本框输入参数
        String productName=request.getParameter("productName"); System.out.println("productName="+productName); } /** * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // TODO Auto-generated method stub
 doGet(request, response); } }

建立一个CharacterEncodingFilter类来实现Filter接口，并实现Filter全部方法post

import java.io.IOException; import javax.servlet.Filter; import javax.servlet.FilterChain; import javax.servlet.FilterConfig; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; public class CharacterEncodingFilter implements Filter { @Override public void destroy() { // TODO Auto-generated method stub
 } @Override public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { request.setCharacterEncoding("utf-8"); chain.doFilter(request, response); } @Override public void init(FilterConfig arg0) throws ServletException { // TODO Auto-generated method stub
 } }

web.xml配置:ui

结果:spa

若是要处理Get请求的中文乱码，这时候须要对request对象进行加强处理。code