package com.loaderman.demo.a_loginFilter; import java.io.IOException; import java.lang.reflect.InvocationHandler; import java.lang.reflect.Method; import java.lang.reflect.Proxy; import javax.servlet.Filter; import javax.servlet.FilterChain; import javax.servlet.FilterConfig; import javax.servlet.ServletException; import javax.servlet.ServletRequest; import javax.servlet.ServletResponse; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; /** * 编码处理统一写到这里(servlet中不需要再处理编码) * */ public class EncodingFilter implements Filter { // 过滤器业务处理方法：处理的公用的业务逻辑操作 @Override public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException { // 转型 final HttpServletRequest request = (HttpServletRequest) req; HttpServletResponse response = (HttpServletResponse) res; // 一、处理公用业务 request.setCharacterEncoding("UTF-8"); // POST提交有效 response.setContentType("text/html;charset=UTF-8"); /* * 出现GET中文乱码，是因为在request.getParameter方法内部没有进行提交方式判断并处理。 * String name = request.getParameter("userName"); * * 解决：对指定接口的某一个方法进行功能扩展，可以使用代理! * 对request对象(目标对象)，创建代理对象！ */ HttpServletRequest proxy = (HttpServletRequest) Proxy.newProxyInstance( request.getClass().getClassLoader(), // 指定当前使用的累加载器 new Class[]{HttpServletRequest.class}, // 对目标对象实现的接口类型 new InvocationHandler() { // 事件处理器 @Override public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { // 定义方法返回值 Object returnValue = null; // 获取方法名 String methodName = method.getName(); // 判断：对getParameter方法进行GET提交中文处理 if ("getParameter".equals(methodName)) { // 获取请求数据值【 <input type="text" name="userName">】 String value = request.getParameter(args[0].toString()); // 调用目标对象的方法 // 获取提交方式 String methodSubmit = request.getMethod(); // 直接调用目标对象的方法 // 判断如果是GET提交，需要对数据进行处理 (POST提交已经处理过了) if ("GET".equals(methodSubmit)) { if (value != null && !"".equals(value.trim())){ // 处理GET中文 value = new String(value.getBytes("ISO8859-1"),"UTF-8"); } } return value; } else { // 执行request对象的其他方法 returnValue = method.invoke(request, args); } return returnValue; } }); // 二、放行 (执行下一个过滤器或者servlet) chain.doFilter(proxy, response); // 传入代理对象 } @Override public void init(FilterConfig filterConfig) throws ServletException { } @Override public void destroy() { } }
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>My JSP 'index.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"> </head> <body> <form name="frmLogin" action="${pageContext.request.contextPath }/login" method="post"> 用户名: <input type="text" name="userName"><br/> <input type="submit" value="POST提交" > </form> <hr/> <form name="frmLogin" action="${pageContext.request.contextPath }/login" method="get"> 用户名: <input type="text" name="userName"><br/> <input type="submit" value="GET提交" > </form> </body> </html>
<!--1. 编码处理过滤器配置 --> <filter> <filter-name>encoding</filter-name> <filter-class>com.loaderman.demo.a_loginFilter.EncodingFilter</filter-class> </filter> <filter-mapping> <filter-name>encoding</filter-name> <url-pattern>/*</url-pattern> </filter-mapping>
package com.loaderman.demo.a_loginFilter; 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 LoginServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { // 获取请求数据 String name = request.getParameter("userName"); System.out.println("用户：" + name); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { this.doGet(request, response); } }