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【web】赵雅智_Filter常见使用

热度：503   发布时间：2012-12-27 10:17:10.0
【web】赵雅智_Filter常见应用

统一全站字符编码的过滤器

  • 通过配置参数encoding指明使用何种字符编码,以处理Html Form请求参数的中文问题

没配置过滤器：

CharseterEncodingFilter.java

package com.hbsi.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;

public class CharseterEncodingFilter implements Filter {

	private FilterConfig config = null;
	private String defaultCharset = "UTF-8";
	public void destroy() {
		// TODO Auto-generated method stub

	}

	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		// TODO Auto-generated method stub
		String charset = config.getInitParameter("charset");
		if(charset==null){
			charset = defaultCharset;
		}
		request.setCharacterEncoding(charset);
		
		//如果是servlet进行相应设置
		response.setCharacterEncoding("UTF-8");
		response.setContentType("text/html;charset="+charset);
		
		chain.doFilter(request, response);
	}

	public void init(FilterConfig filterConfig) throws ServletException {
		// TODO Auto-generated method stub
		this.config = filterConfig;
	}

}

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
	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_2_5.xsd">
	<!--  
	<filter>
		<filter-name>FilterChain</filter-name>
		<filter-class>com.hbsi.filter.FilterChain</filter-class>
	</filter>
	<filter-mapping>
		<filter-name>FilterChain</filter-name>
		<url-pattern>*.jsp</url-pattern>
	</filter-mapping>
	
	<filter>
		<filter-name>FilterDemo1</filter-name>
		<filter-class>com.hbsi.filter.FilterDemo1</filter-class>
	</filter>
	<filter-mapping>
		<filter-name>FilterDemo1</filter-name>
		<url-pattern>*.html</url-pattern>
	</filter-mapping>
	
	<filter>
		<filter-name>FilterShengZhou</filter-name>
		<filter-class>com.hbsi.filter.FilterShengZhou</filter-class>
		<init-param>
			<param-name>abc</param-name>
			<param-value>aaaaa</param-value>
		</init-param>
	</filter>
	<filter-mapping>
		<filter-name>FilterShengZhou</filter-name>
		<url-pattern>*.jsp</url-pattern>
	</filter-mapping>
	-->

  
  <servlet>
    <description>This is the description of my J2EE component</description>
    <display-name>This is the display name of my J2EE component</display-name>
    <servlet-name>LuanMaServlet</servlet-name>
    <servlet-class>com.hbsi.servlet.LuanMaServlet</servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>LuanMaServlet</servlet-name>
    <url-pattern>/servlet/luanMa.do</url-pattern>
  </servlet-mapping>
	
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>

LuanMaServlet.java 

package com.hbsi.servlet;

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 LuanMaServlet extends HttpServlet {
	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		String city = request.getParameter("city");
		response.getWriter().write(city);

	}

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		doGet(request, response);
	}
}

luanMa.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'luanMa.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">    
	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
	<meta http-equiv="description" content="This is my page">
	<!--
	<link rel="stylesheet" type="text/css" href="styles.css">
	-->

  </head>
  
  <body>
  <form action="servlet/luanMa.do" method="post">
     城市:<input type="text" name="city"/>
     <input type="submit" value="提交"/>
  </form>
  </body>
</html>


配置过滤器：

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
	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_2_5.xsd">
	<!--  
	<filter>
		<filter-name>FilterChain</filter-name>
		<filter-class>com.hbsi.filter.FilterChain</filter-class>
	</filter>
	<filter-mapping>
		<filter-name>FilterChain</filter-name>
		<url-pattern>*.jsp</url-pattern>
	</filter-mapping>
	
	<filter>
		<filter-name>FilterDemo1</filter-name>
		<filter-class>com.hbsi.filter.FilterDemo1</filter-class>
	</filter>
	<filter-mapping>
		<filter-name>FilterDemo1</filter-name>
		<url-pattern>*.html</url-pattern>
	</filter-mapping>
	
	<filter>
		<filter-name>FilterShengZhou</filter-name>
		<filter-class>com.hbsi.filter.FilterShengZhou</filter-class>
		<init-param>
			<param-name>abc</param-name>
			<param-value>aaaaa</param-value>
		</init-param>
	</filter>
	<filter-mapping>
		<filter-name>FilterShengZhou</filter-name>
		<url-pattern>*.jsp</url-pattern>
	</filter-mapping>
	-->
	<filter>
		<filter-name>CharseterEncodingFilter</filter-name>
    	<filter-class>com.hbsi.filter.CharseterEncodingFilter</filter-class>
    	<init-param>
    		<param-name>charset</param-name>
    		<param-value>UTF-8</param-value>
		</init-param>
	</filter>
	<filter-mapping>
		<filter-name>CharseterEncodingFilter</filter-name>
		<url-pattern>*.jsp</url-pattern>
	</filter-mapping>
	<filter-mapping>
		<filter-name>CharseterEncodingFilter</filter-name>
		<url-pattern>/servlet/*</url-pattern>
	</filter-mapping>
  
  <servlet>
    <description>This is the description of my J2EE component</description>
    <display-name>This is the display name of my J2EE component</display-name>
    <servlet-name>LuanMaServlet</servlet-name>
    <servlet-class>com.hbsi.servlet.LuanMaServlet</servlet-class>
  </servlet>


  <servlet-mapping>
    <servlet-name>LuanMaServlet</servlet-name>
    <url-pattern>/servlet/luanMa.do</url-pattern>
  </servlet-mapping>
	
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>




禁止浏览器缓存所有动态页面的过滤器

  • 有 3 个 HTTP 响应头字段都可以禁止浏览器缓存当前页面，它们在 Servlet 中的示例代码如下：
    • response.setDateHeader("Expires",-1);
    • response.setHeader("Cache-Control","no-cache"); 
    • response.setHeader("Pragma","no-cache"); 
  • 并不是所有的浏览器都能完全支持上面的三个响应头，因此最好是同时使用上面的三个响应头。
  • Expires数据头：值为GMT时间值，为-1指浏览器不要缓存页面
  • Cache-Control响应头有两个常用值： 
    • no-cache指浏览器不要缓存当前页面。
    • max-age:xxx指浏览器缓存页面xxx秒。

允许缓存:不编写过滤器

NoCacheFilter.java

package com.hbsi.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.HttpServletResponse;

public class NoCacheFilter implements Filter {

	public void destroy() {
		// TODO Auto-generated method stub
		
	}

	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		// TODO Auto-generated method stub
		HttpServletRequest req = (HttpServletRequest) request;
		HttpServletResponse resp = (HttpServletResponse) response;
		resp.setDateHeader("expires",-1);
		resp.setHeader("Cache-Control", "no-cache");
		resp.setHeader("Pragma", "no-cache");
		
		chain.doFilter(req,resp);
		
	}

	public void init(FilterConfig filterConfig) throws ServletException {
		// TODO Auto-generated method stub
		
	}
}

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
	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_2_5.xsd">
	<!--  
	<filter>
		<filter-name>FilterChain</filter-name>
		<filter-class>com.hbsi.filter.FilterChain</filter-class>
	</filter>
	<filter-mapping>
		<filter-name>FilterChain</filter-name>
		<url-pattern>*.jsp</url-pattern>
	</filter-mapping>
	
	<filter>
		<filter-name>FilterDemo1</filter-name>
		<filter-class>com.hbsi.filter.FilterDemo1</filter-class>
	</filter>
	<filter-mapping>
		<filter-name>FilterDemo1</filter-name>
		<url-pattern>*.html</url-pattern>
	</filter-mapping>
	
	<filter>
		<filter-name>FilterShengZhou</filter-name>
		<filter-class>com.hbsi.filter.FilterShengZhou</filter-class>
		<init-param>
			<param-name>abc</param-name>
			<param-value>aaaaa</param-value>
		</init-param>
	</filter>
	<filter-mapping>
		<filter-name>FilterShengZhou</filter-name>
		<url-pattern>*.jsp</url-pattern>
	</filter-mapping>
	-->
	<filter>
		<filter-name>CharseterEncodingFilter</filter-name>
    	<filter-class>com.hbsi.filter.CharseterEncodingFilter</filter-class>
    	<init-param>
    		<param-name>charset</param-name>
    		<param-value>UTF-8</param-value>
		</init-param>
	</filter>
	<filter-mapping>
		<filter-name>CharseterEncodingFilter</filter-name>
		<url-pattern>*.jsp</url-pattern>
	</filter-mapping>
	<filter-mapping>
		<filter-name>CharseterEncodingFilter</filter-name>
		<url-pattern>/servlet/*</url-pattern>
	</filter-mapping>
	
  
  <servlet>
    <description>This is the description of my J2EE component</description>
    <display-name>This is the display name of my J2EE component</display-name>
    <servlet-name>LuanMaServlet</servlet-name>
    <servlet-class>com.hbsi.servlet.LuanMaServlet</servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>LuanMaServlet</servlet-name>
    <url-pattern>/servlet/luanMa.do</url-pattern>
  </servlet-mapping>
	
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>


访问luanMa.jsp



编写过滤器禁止缓存：

NoCacheFilter.java

package com.hbsi.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.HttpServletResponse;

public class NoCacheFilter implements Filter {

	public void destroy() {
		// TODO Auto-generated method stub
		
	}

	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		// TODO Auto-generated method stub
		HttpServletRequest req = (HttpServletRequest) request;
		HttpServletResponse resp = (HttpServletResponse) response;
		resp.setDateHeader("expires",-1);
		resp.setHeader("Cache-Control", "no-cache");
		resp.setHeader("Pragma", "no-cache");
		
		chain.doFilter(req,resp);
		
	}

	public void init(FilterConfig filterConfig) throws ServletException {
		// TODO Auto-generated method stub
		
	}
}

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
	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_2_5.xsd">
	<!--  
	<filter>
		<filter-name>FilterChain</filter-name>
		<filter-class>com.hbsi.filter.FilterChain</filter-class>
	</filter>
	<filter-mapping>
		<filter-name>FilterChain</filter-name>
		<url-pattern>*.jsp</url-pattern>
	</filter-mapping>
	
	<filter>
		<filter-name>FilterDemo1</filter-name>
		<filter-class>com.hbsi.filter.FilterDemo1</filter-class>
	</filter>
	<filter-mapping>
		<filter-name>FilterDemo1</filter-name>
		<url-pattern>*.html</url-pattern>
	</filter-mapping>
	
	<filter>
		<filter-name>FilterShengZhou</filter-name>
		<filter-class>com.hbsi.filter.FilterShengZhou</filter-class>
		<init-param>
			<param-name>abc</param-name>
			<param-value>aaaaa</param-value>
		</init-param>
	</filter>
	<filter-mapping>
		<filter-name>FilterShengZhou</filter-name>
		<url-pattern>*.jsp</url-pattern>
	</filter-mapping>
	-->
	<filter>
		<filter-name>CharseterEncodingFilter</filter-name>
    	<filter-class>com.hbsi.filter.CharseterEncodingFilter</filter-class>
    	<init-param>
    		<param-name>charset</param-name>
    		<param-value>UTF-8</param-value>
		</init-param>
	</filter>
	<filter-mapping>
		<filter-name>CharseterEncodingFilter</filter-name>
		<url-pattern>*.jsp</url-pattern>
	</filter-mapping>
	<filter-mapping>
		<filter-name>CharseterEncodingFilter</filter-name>
		<url-pattern>/servlet/*</url-pattern>
	</filter-mapping>
	
	<filter>
    	<filter-name>NoCahceFilter</filter-name>
    	<filter-class>com.hbsi.filter.NoCacheFilter</filter-class>
    </filter>
	<filter-mapping>
		<filter-name>NoCahceFilter</filter-name>
		<url-pattern>*.jsp</url-pattern>
	</filter-mapping>
	<filter-mapping>
		<filter-name>NoCahceFilter</filter-name>
		<url-pattern>/servlet/*</url-pattern>
	</filter-mapping>
  
  <servlet>
    <description>This is the description of my J2EE component</description>
    <display-name>This is the display name of my J2EE component</display-name>
    <servlet-name>LuanMaServlet</servlet-name>
    <servlet-class>com.hbsi.servlet.LuanMaServlet</servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>LuanMaServlet</servlet-name>
    <url-pattern>/servlet/luanMa.do</url-pattern>
  </servlet-mapping>
	
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>


控制浏览器缓存页面中的静态资源的过滤器：

  • 场景：有些动态页面中引用了一些图片或css文件以修饰页面效果，这些图片和css文件经常是不变化的，所以为减轻服务器的压力，可以使用filter控制浏览器缓存这些文件，以提升服务器的性能。

ExpiresFilter.java

package com.hbsi.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.HttpServletResponse;
//控制浏览器可以缓存js，css，jpg。
public class ExpiresFilter implements Filter {

	private FilterConfig config;
	public void destroy() {
		// TODO Auto-generated method stub

	}

	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		// TODO Auto-generated method stub
		HttpServletRequest req = (HttpServletRequest) request;
		HttpServletResponse resp = (HttpServletResponse) response;
		
		String uri = req.getRequestURI();
		if(uri.endsWith(".css")){
			long time = Integer.parseInt(config.getInitParameter("css"))*1000;
			resp.setDateHeader("expires",System.currentTimeMillis()+time);
		}else if(uri.endsWith(".js")){
			long time = Integer.parseInt(config.getInitParameter("js"))*1000;
			resp.setDateHeader("expires",System.currentTimeMillis()+time);
		}else if(uri.endsWith(".jpg")){
			long time = Integer.parseInt(config.getInitParameter("jpg"))*1000;
			resp.setDateHeader("expires",System.currentTimeMillis()+time);
		}
		chain.doFilter(req, resp);
	}

	public void init(FilterConfig filterConfig) throws ServletException {
		// TODO Auto-generated method stub
		this.config = filterConfig;
	}

}


web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
	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_2_5.xsd">
	<!--  
	<filter>
		<filter-name>FilterChain</filter-name>
		<filter-class>com.hbsi.filter.FilterChain</filter-class>
	</filter>
	<filter-mapping>
		<filter-name>FilterChain</filter-name>
		<url-pattern>*.jsp</url-pattern>
	</filter-mapping>
	
	<filter>
		<filter-name>FilterDemo1</filter-name>
		<filter-class>com.hbsi.filter.FilterDemo1</filter-class>
	</filter>
	<filter-mapping>
		<filter-name>FilterDemo1</filter-name>
		<url-pattern>*.html</url-pattern>
	</filter-mapping>
	
	<filter>
		<filter-name>FilterShengZhou</filter-name>
		<filter-class>com.hbsi.filter.FilterShengZhou</filter-class>
		<init-param>
			<param-name>abc</param-name>
			<param-value>aaaaa</param-value>
		</init-param>
	</filter>
	<filter-mapping>
		<filter-name>FilterShengZhou</filter-name>
		<url-pattern>*.jsp</url-pattern>
	</filter-mapping>
	-->
	<filter>
		<filter-name>CharseterEncodingFilter</filter-name>
    	<filter-class>com.hbsi.filter.CharseterEncodingFilter</filter-class>
    	<init-param>
    		<param-name>charset</param-name>
    		<param-value>UTF-8</param-value>
		</init-param>
	</filter>
	<filter-mapping>
		<filter-name>CharseterEncodingFilter</filter-name>
		<url-pattern>*.jsp</url-pattern>
	</filter-mapping>
	<filter-mapping>
		<filter-name>CharseterEncodingFilter</filter-name>
		<url-pattern>/servlet/*</url-pattern>
	</filter-mapping>
	
	<filter>
    	<filter-name>NoCahceFilter</filter-name>
    	<filter-class>com.hbsi.filter.NoCacheFilter</filter-class>
    </filter>
	<filter-mapping>
		<filter-name>NoCahceFilter</filter-name>
		<url-pattern>*.jsp</url-pattern>
	</filter-mapping>
	<filter-mapping>
		<filter-name>NoCahceFilter</filter-name>
		<url-pattern>/servlet/*</url-pattern>
	</filter-mapping>
	
	<filter>
		<filter-name>ExpiresFilter</filter-name>
		<filter-class>com.hbsi.filter.ExpiresFilter</filter-class>
	    <init-param>
			<param-name>css</param-name>
			<param-value>120</param-value>
	    </init-param>
		<init-param>
			<param-name>jpg</param-name>
			<param-value>120</param-value>
		</init-param>
		<init-param>
			<param-name>js</param-name>
			<param-value>120</param-value>
	    </init-param> 
	</filter>
	<filter-mapping>
		<filter-name>ExpiresFilter</filter-name>
		<url-pattern>*.css</url-pattern>
	</filter-mapping>
	<filter-mapping>
		<filter-name>ExpiresFilter</filter-name>
		<url-pattern>*.jpg</url-pattern>
	</filter-mapping>
	<filter-mapping>
		<filter-name>ExpiresFilter</filter-name>
		<url-pattern>*.js</url-pattern>
	</filter-mapping>
  
  <servlet>
    <description>This is the description of my J2EE component</description>
    <display-name>This is the display name of my J2EE component</display-name>
    <servlet-name>LuanMaServlet</servlet-name>
    <servlet-class>com.hbsi.servlet.LuanMaServlet</servlet-class>
  </servlet>

  <servlet-mapping>
    <servlet-name>LuanMaServlet</servlet-name>
    <url-pattern>/servlet/luanMa.do</url-pattern>
  </servlet-mapping>
	
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>


expiresFilter.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>
    <base href="<%=basePath%>">
    
    <title>My JSP 'expiresFilter.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">    
	<meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
	<meta http-equiv="description" content="This is my page">
	<!--
	<link rel="stylesheet" type="text/css" href="styles.css">
	-->

  </head>
  
  <body>
  	<img src="tu.jpg">
  </body>
</html>



实现用户自动登陆的过滤器

  • 在用户登陆成功后，发送一个名称为user的cookie给客户端，cookie的值为用户名和md5加密后的密码。
  • 编写一个AutoLoginFilter，这个filter检查用户是否带有名称为user的cookie来，如果有，则调用dao查询cookie的用户名和密码是否和数据库匹配，匹配则向session中存入user对象（即用户登陆标记），以实现程序完成自动登陆。

login.jsp

建表：


DBUtils连接数据库倒包

c3p0_config.xml

<?xml version="1.0" encoding="UTF-8"?>


<c3p0-config>
	<default-config>
		<property name="driverClass">com.mysql.jdbc.Driver</property>
		<property name="jdbcUrl">jdbc:mysql://localhost:3306/filter</property>
		<property name="user">root</property>
		<property name="password">123456</property>
		
		<property name="acquireIncrement">5</property>
		<property name="initialPoolSize">10</property>
		<property name="minPoolSize">5</property>
		<property name="maxPoolSize">20</property>
		
		
	</default-config>

	<named-config name="mysql">
		<property name="driverClass">com.mysql.jdbc.Driver</property>
		<property name="jdbcUrl">jdbc:mysql://localhost:3306/filter</property>
		<property name="user">root</property>
		<property name="password">123456</property>
		<property name="acquireIncrement">5</property>
		<property name="initialPoolSize">10</property>
		<property name="minPoolSize">5</property>
		<property name="maxPoolSize">20</property>
	</named-config>

</c3p0-config>
DBManger.java

package com.hbsi.util;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import javax.sql.DataSource;

import com.mchange.v2.c3p0.ComboPooledDataSource;
public class DBManager {
	private static ComboPooledDataSource ds = null;
	static{
		try{
			//创建连接池			
			ds = new ComboPooledDataSource("mysql");
		}catch(Exception e){
			e.printStackTrace();
		}
	}

	//获取链接
	public static DataSource getDataSource(){
		return ds;
	}

}

User.java

package com.hbsi.domain;

public class User {
	private String username;
	private String password;
	public String getPassword() {
		return password;
	}
	public void setPassword(String password) {
		this.password = password;
	}
	public void setUsername(String username) {
		this.username = username;
	}
	public String getUsername() {
		return username;
	}
}


UserDao.java

package com.hbsi.dao;

import java.util.List;

import com.hbsi.domain.User;

public interface UserDao {
	
	public List<User> getAll();
	
	public User find(String username,String password);
	
	public User find(String username);
}


UserDaoImpl.java

package com.hbsi.dao;

import java.util.List;

import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanHandler;
import org.apache.commons.dbutils.handlers.BeanListHandler;

import com.hbsi.domain.User;
import com.hbsi.util.DBManager;

public class UserDaoImpl implements UserDao {
	
	public List<User> getAll(){
		try{
			QueryRunner runner = new QueryRunner(DBManager.getDataSource());
			String sql = "select * from user";
			
			return (List<User>) runner.query(sql,new BeanListHandler(User.class));
			
		}catch(Exception e){
			throw new RuntimeException();
		}
	}
	
	public User find(String username,String password){
		try{
			QueryRunner runner = new QueryRunner(DBManager.getDataSource());
			
			String sql = "select * from user where username=? and password=?";
			Object[] params = {username,password};
			
			return (User) runner.query(sql, params, new BeanHandler(User.class));
			
		}catch(Exception e){
			e.printStackTrace();
			throw new RuntimeException(e);
		}
	}
	
	public User find(String username){
		try{
			QueryRunner runner = new QueryRunner(DBManager.getDataSource());
			
			String sql = "select * from user where username=?";
			
			
			return (User) runner.query(sql, username, new BeanHandler(User.class));
			
		}catch(Exception e){
			throw new RuntimeException();
		}
	}

}


LoginServlet.java

package com.hbsi.servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;

import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import sun.misc.BASE64Encoder;

import com.hbsi.dao.UserDao;
import com.hbsi.dao.UserDaoImpl;
import com.hbsi.domain.User;

public class LoginServlet extends HttpServlet {

	public void doGet(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {
		
		String username = request.getParameter("username");
		String password = request.getParameter("password");
		int autoLoginTime =Integer.parseInt(request.getParameter("autoLoginTime"));
		
		UserDao dao = new UserDaoImpl();
		User user = dao.find(username, password);
		
		if(user != null){
			//放到session域
			request.getSession().setAttribute("user",user);

			Cookie cookie1 = new Cookie("username",user.getUsername());
			Cookie cookie2 = new Cookie("password",user.getPassword());
			
			cookie1.setMaxAge(autoLoginTime);
			cookie2.setMaxAge(autoLoginTime);
			
			cookie1.setPath("/Filter");
			cookie2.setPath("/Filter");
			
			response.addCookie(cookie1);
			response.addCookie(cookie2);
			
			//重定向
			response.sendRedirect("../ChangJianYingYong/welcome.jsp");
			
		}else{
			request.setAttribute("message","用户名密码错");
			request.getRequestDispatcher("../ChangJianYingYong/message.jsp").forward(request, response);
		}
		
	}
	
	private String md5(String input){
		try {
			MessageDigest md = MessageDigest.getInstance("md5");
			byte[] result = md.digest(input.getBytes());
			BASE64Encoder encoder = new BASE64Encoder();
			return encoder.encode(result);
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
			throw new RuntimeException(e);
		}
		
	}
	

	public void doPost(HttpServletRequest request, HttpServletResponse response)
			throws ServletException, IOException {

		doGet(request, response);
	}

}


AutoLoginFilter.java

package com.hbsi.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.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.hbsi.dao.UserDao;
import com.hbsi.dao.UserDaoImpl;
import com.hbsi.domain.User;

public class AutoLoginFilter implements Filter {

	public void destroy() {
		// TODO Auto-generated method stub
		
	}

	public void doFilter(ServletRequest request, ServletResponse response,
			FilterChain chain) throws IOException, ServletException {
		// TODO Auto-generated method stub
		HttpServletRequest req = (HttpServletRequest) request;
		HttpServletResponse resp = (HttpServletResponse) response;
		
		//1.检查用户是否登录
		User user = (User) req.getSession().getAttribute("user");
		if(user!=null){
			chain.doFilter(req,resp);
			return;
		}
		
		//2.检查用户是否带cookie来
		String username = null;
		String password = null;
		Cookie[] cookies = req.getCookies();
		for(int i=0;cookies!=null && i<cookies.length;i++){
			if(cookies[i].getName().equals("username")){
				username = cookies[i].getValue();
			}
			if(cookies[i].getName().equals("password")){
				password = cookies[i].getValue();
			}
		}
		if(username==null && password==null){
			chain.doFilter(req, resp);
			return;
		}
		
		UserDao dao = new UserDaoImpl();
		User user1 = dao.find(username);
		String save_password = user1.getPassword();
		if(!password.equals(save_password)){
			chain.doFilter(req, resp);
			return;
		}
		req.getSession().setAttribute("user",user1);
		chain.doFilter(req, resp);
	}

	public void init(FilterConfig filterConfig) throws ServletException {
		// TODO Auto-generated method stub
		
	}

}

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
	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_2_5.xsd">
	<!--  
	<filter>
		<filter-name>FilterChain</filter-name>
		<filter-class>com.hbsi.filter.FilterChain</filter-class>
	</filter>
	<filter-mapping>
		<filter-name>FilterChain</filter-name>
		<url-pattern>*.jsp</url-pattern>
	</filter-mapping>
	
	<filter>
		<filter-name>FilterDemo1</filter-name>
		<filter-class>com.hbsi.filter.FilterDemo1</filter-class>
	</filter>
	<filter-mapping>
		<filter-name>FilterDemo1</filter-name>
		<url-pattern>*.html</url-pattern>
	</filter-mapping>
	
	<filter>
		<filter-name>FilterShengZhou</filter-name>
		<filter-class>com.hbsi.filter.FilterShengZhou</filter-class>
		<init-param>
			<param-name>abc</param-name>
			<param-value>aaaaa</param-value>
		</init-param>
	</filter>
	<filter-mapping>
		<filter-name>FilterShengZhou</filter-name>
		<url-pattern>*.jsp</url-pattern>
	</filter-mapping>
	-->
	<filter>
		<filter-name>CharseterEncodingFilter</filter-name>
    	<filter-class>com.hbsi.filter.CharseterEncodingFilter</filter-class>
    	<init-param>
    		<param-name>charset</param-name>
    		<param-value>UTF-8</param-value>
		</init-param>
	</filter>
	<filter-mapping>
		<filter-name>CharseterEncodingFilter</filter-name>
		<url-pattern>*.jsp</url-pattern>
	</filter-mapping>
	<filter-mapping>
		<filter-name>CharseterEncodingFilter</filter-name>
		<url-pattern>/servlet/*</url-pattern>
	</filter-mapping>
	
	<filter>
    	<filter-name>NoCahceFilter</filter-name>
    	<filter-class>com.hbsi.filter.NoCacheFilter</filter-class>
    </filter>
	<filter-mapping>
		<filter-name>NoCahceFilter</filter-name>
		<url-pattern>*.jsp</url-pattern>
	</filter-mapping>
	<filter-mapping>
		<filter-name>NoCahceFilter</filter-name>
		<url-pattern>/servlet/*</url-pattern>
	</filter-mapping>
	
	<filter>
		<filter-name>ExpiresFilter</filter-name>
		<filter-class>com.hbsi.filter.ExpiresFilter</filter-class>
	    <init-param>
			<param-name>css</param-name>
			<param-value>120</param-value>
	    </init-param>
		<init-param>
			<param-name>jpg</param-name>
			<param-value>120</param-value>
		</init-param>
		<init-param>
			<param-name>js</param-name>
			<param-value>120</param-value>
	    </init-param> 
	</filter>
	<filter-mapping>
		<filter-name>ExpiresFilter</filter-name>
		<url-pattern>*.css</url-pattern>
	</filter-mapping>
	<filter-mapping>
		<filter-name>ExpiresFilter</filter-name>
		<url-pattern>*.jpg</url-pattern>
	</filter-mapping>
	<filter-mapping>
		<filter-name>ExpiresFilter</filter-name>
		<url-pattern>*.js</url-pattern>
	</filter-mapping>
  
  <servlet>
    <description>This is the description of my J2EE component</description>
    <display-name>This is the display name of my J2EE component</display-name>
    <servlet-name>LuanMaServlet</servlet-name>
    <servlet-class>com.hbsi.servlet.LuanMaServlet</servlet-class>
  </servlet>
  <servlet>
    <description>This is the description of my J2EE component</description>
    <display-name>This is the display name of my J2EE component</display-name>
    <servlet-name>LoginServlet</servlet-name>
    <servlet-class>com.hbsi.servlet.LoginServlet</servlet-class>
  </servlet>

  <filter>
    <filter-name>AutoLoginFilter</filter-name>
    <filter-class>com.hbsi.filter.AutoLoginFilter</filter-class>
  </filter>
  <filter-mapping>
     <filter-name>AutoLoginFilter</filter-name>
     <url-pattern>/*</url-pattern>
     
  </filter-mapping>
  
  <servlet-mapping>
    <servlet-name>LuanMaServlet</servlet-name>
    <url-pattern>/servlet/luanMa.do</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
    <servlet-name>LoginServlet</servlet-name>
    <url-pattern>/servlet/LoginServlet</url-pattern>
  </servlet-mapping>
	
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>

welcome.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>   
    <title>My JSP 'welcome.jsp' starting page</title> 	
  </head>
  
  <body>
    欢迎您：${user.username} <br>
  </body>
</html>


message.jsp

<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
  <head>   
    <title>My JSP 'message.jsp' starting page</title> 	
  </head>
  
  <body>
   ${message}<br>
  </body>
</html>







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