过滤器的一些配置细节

来源：互联网发布：小米5x和小米max2知乎编辑：程序博客网时间：2024/05/16 06:20

如何过滤转发、包含、异常的资源。
1。FilterCfgDemo.java:

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 FilterCfgDemo implements Filter {    @Override    public void init(FilterConfig filterConfig) throws ServletException {    }    @Override    public void doFilter(ServletRequest request, ServletResponse response,            FilterChain chain) throws IOException, ServletException {        System.out.println("过滤了");        chain.doFilter(request, response);    }    @Override    public void destroy() {        // TODO Auto-generated method stub    }}

2.web.xml文件：

<?xml version="1.0" encoding="UTF-8"?><web-app version="3.0"    xmlns="http://java.sun.com/xml/ns/javaee"    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"><filter>    <filter-name>FilterDemo1</filter-name>    <filter-class>FilterCfgDemo</filter-class></filter><filter-mapping>    <filter-name>FilterDemo1</filter-name>    <url-pattern>/*</url-pattern>    <dispatcher>REQUEST</dispatcher>    <dispatcher>FORWARD</dispatcher>    <dispatcher>INCLUDE</dispatcher>    <dispatcher>ERROR</dispatcher></filter-mapping><error-page>    <exception-type>java.lang.Exception</exception-type>    <location>/error.jsp</location></error-page></web-app>

3。1.jsp文件：

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>    <title>title</title>    <meta http-equiv="pragma" content="no-cache">    <meta http-equiv="cache-control" content="no-cache">    <meta http-equiv="expires" content="0">    <!--    <link rel="stylesheet" type="text/css" href="styles.css">    -->  </head>  <body>    1111111111  </body></html>

4。2.jsp文件：

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>    <title>title</title>    <meta http-equiv="pragma" content="no-cache">    <meta http-equiv="cache-control" content="no-cache">    <meta http-equiv="expires" content="0">    <!--    <link rel="stylesheet" type="text/css" href="styles.css">    -->  </head>  <body>    222222  </body></html>

5。3.jsp文件：

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html>  <head>    <title>title</title>    <meta http-equiv="pragma" content="no-cache">    <meta http-equiv="cache-control" content="no-cache">    <meta http-equiv="expires" content="0">    <!--    <link rel="stylesheet" type="text/css" href="styles.css">    -->  </head>  <body>   333333  </body></html>

6。运行：http://localhost:8080/Filter_project/3.jsp
结果：服务器端输出“过滤了”，页面输出“333333”
运行：http://localhost:8080/Filter_project/2.jsp
结果：服务器端输出“过滤了”，页面输出“222222”

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