过滤器的使用
Posted jokerzou
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过滤器Filter的工作原理:
过滤前英文登录界面：
过滤前英文登录结果：
过滤后中文登录界面：
过滤后中文登录结果：
项目结构：
1 <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%> 2 <% 3 String path = request.getContextPath(); 4 String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/"; 5 %> 6 7 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 8 <html> 9 <head> 10 <base href="<%=basePath%>"> 11 12 <title>My JSP ‘index.jsp‘ starting page</title> 13 <meta http-equiv="pragma" content="no-cache"> 14 <meta http-equiv="cache-control" content="no-cache"> 15 <meta http-equiv="expires" content="0"> 16 <meta http-equiv="keywords" content="keyword1,keyword2,keyword3"> 17 <meta http-equiv="description" content="This is my page"> 18 <!-- 19 <link rel="stylesheet" type="text/css" href="styles.css"> 20 --> 21 </head> 22 23 <body> 24 <div> 25 请登录 26 <div> 27 <form action="ShowLoginInfo" id="eee" method="get"> 28 <br><br> 29 账号:<input type="text" name="uname"> 30 <br><br><br> 31 密码: <input type="password" name="upassword"> 32 <br><br> 33 <button type="submit" id="btn">登录</button> 34 </form> 35 </div> 36 </div> 37 </body> 38 </html>
1 package com.a; 2 3 import java.io.IOException; 4 import java.io.PrintWriter; 5 6 import javax.servlet.ServletException; 7 import javax.servlet.annotation.WebServlet; 8 import javax.servlet.http.HttpServlet; 9 import javax.servlet.http.HttpServletRequest; 10 import javax.servlet.http.HttpServletResponse; 11 12 /** 13 * Servlet implementation class ShowLoginInfo 14 */ 15 @WebServlet("/ShowLoginInfo") 16 public class ShowLoginInfo extends HttpServlet { 17 private static final long serialVersionUID = 1L; 18 19 /** 20 * @see HttpServlet#HttpServlet() 21 */ 22 public ShowLoginInfo() { 23 super(); 24 // TODO Auto-generated constructor stub 25 } 26 27 /** 28 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) 29 */ 30 protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 31 //从请求对象中获得指定参数的值 32 String strName = request.getParameter("uname"); 33 String strPassWord = request.getParameter("upassword"); 34 PrintWriter out = response.getWriter(); 35 out.println("你的名字是："+strName+"<br>"); 36 out.println("你的密码是："+strPassWord); 37 } 38 39 /** 40 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response) 41 */ 42 protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 43 // TODO Auto-generated method stub 44 doGet(request, response); 45 } 46 47 }
1 package com.b; 2 3 import java.io.IOException; 4 import javax.servlet.Filter; 5 import javax.servlet.FilterChain; 6 import javax.servlet.FilterConfig; 7 import javax.servlet.ServletException; 8 import javax.servlet.ServletRequest; 9 import javax.servlet.ServletResponse; 10 import javax.servlet.annotation.WebFilter; 11 12 /** 13 * Servlet Filter implementation class myFilter 14 */ 15 @WebFilter(filterName="myFilter",urlPatterns="/ShowLoginInfo") 16 public class myFilter implements Filter { 17 18 /** 19 * Default constructor. 20 */ 21 public myFilter() { 22 // TODO Auto-generated constructor stub 23 } 24 25 /** 26 * @see Filter#destroy() 27 */ 28 public void destroy() { 29 // TODO Auto-generated method stub 30 } 31 32 /** 33 * @see Filter#doFilter(ServletRequest, ServletResponse, FilterChain) 34 */ 35 public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { 36 request.setCharacterEncoding("UTF-8"); 37 response.setContentType("text/html; charset=UTF-8"); 38 chain.doFilter(request, response); 39 } 40 41 /** 42 * @see Filter#init(FilterConfig) 43 */ 44 public void init(FilterConfig fConfig) throws ServletException { 45 // TODO Auto-generated method stub 46 } 47 48 }
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