编写一个过滤器链实现如下功能：
1． 编写过滤器程序EncodingFilter，实现POST方式下的中文转码。
2． 编写过滤器程序liuyanfilter，实现将用户输入的用户名“张”转换成“李”，将用户输入的留言内容“剑桥”转换成“****”。
程序其他功能页面：
1． 编写liuyanform.jsp该页面用于完成表单的输入，其中包括：用户名、留言内容、提交按钮。
2． 编写liuyanservlet在该程序中的doPost（）方法中使用请求转发的形式将程序跳转到liuyanresult.jsp
3． 编写liuyanresult.jsp程序，在该页面中输出用户提交的用户名及留言内容。
注：两个过滤器程序均对liuyanservlet程序进行过滤
<%@ page language="java" import="java.util.*" pageEncoding="GBK"%> <html> <head> </head> <body> <form action="MessageServlet" method="post"> <table> <tr> <td> 标题： <input type="text" name="title" size="30"> </td> </tr> <tr> <td> 内容： <textarea rows="5" cols="40" name="content"></textarea> </td> </tr> <tr> <td> <input type="submit" name="submit" value="提交"> </td> </tr> </table> </form> </body> </html>
<%@ page language="java" import="java.util.*" pageEncoding="gbk"%>
<html>
<head>
</head>
<body>
用户名 ：<%=request.getAttribute("title")%><br/>
留言信息：<%=request.getAttribute("content")%>
</body>
</html>
<?xml version="1.0" encoding="UTF-8"?> <web-app version="2.4" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd"> <filter> <filter-name>CharacterFilter</filter-name> <filter-class>com.mars.filter.CharacterFilter</filter-class> </filter> <filter> <filter-name>WordFilter</filter-name> <filter-class>com.mars.filter.WordFilter</filter-class> </filter> <filter-mapping> <filter-name>CharacterFilter</filter-name> <url-pattern>/MessageServlet</url-pattern> </filter-mapping> <filter-mapping> <filter-name>WordFilter</filter-name> <url-pattern>/MessageServlet</url-pattern> </filter-mapping> <servlet> <servlet-name>MessageServlet</servlet-name> <servlet-class>com.mars.servlet.MessageServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>MessageServlet</servlet-name> <url-pattern>/MessageServlet</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>submit.jsp</welcome-file> </welcome-file-list> </web-app>
package com.mars.filter;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
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.HttpServletRequestWrapper;
import javax.servlet.http.HttpServletResponse;
public class CharacterFilter implements Filter {
public void init(FilterConfig arg0) throws ServletException {
System.out.println("调用init");
}
public void destroy() {
System.out.println("调用destroy");
}
// 解决post方式的乱码问题
public void doFilter(ServletRequest req, ServletResponse resp,
FilterChain chain) throws IOException, ServletException {
HttpServletRequest request = (HttpServletRequest) req;
HttpServletResponse response = (HttpServletResponse) resp;
request.setCharacterEncoding("GBK");
response.setCharacterEncoding("GBK");
response.setContentType("text/html;charset=GBK");
chain.doFilter(request, response);
//chain.doFilter(req, resp);
}
}
package com.mars.filter;
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;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import javax.servlet.http.HttpServletResponse;
public class WordFilter implements Filter {
private FilterConfig config = null;
public void init(FilterConfig filterConfig) throws ServletException {
}
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
HttpServletRequest req=(HttpServletRequest)request;
HttpServletResponse resp=(HttpServletResponse)response;
String title = req.getParameter("title");
String content = req.getParameter("content");
title = title.replace("张", "李");
content = content.replace("剑桥", "****");
req.setAttribute("title", title);
req.setAttribute("content", content);
chain.doFilter(request, response);
}
public void destroy() {
config = null;
}
}
package com.mars.servlet;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class MessageServlet extends HttpServlet {
/* public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request, response);
}*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
request.getRequestDispatcher("result.jsp").forward(request,
response);
}
}