1 package lee;
2
3 import javax.servlet.*;
4 import javax.servlet.http.*;
5 import javax.servlet.annotation.*;
6
7 import java.io.*;
8
9 /**
10 * Description:
11 * <br/>网站: <a href="http://www.crazyit.org">疯狂Java联盟</a>
12 * <br/>Copyright (C), 2001-2016, Yeeku.H.Lee
13 * <br/>This program is protected by copyright laws.
14 * <br/>Program Name:
15 * <br/>Date:
16 * @author Yeeku.H.Lee kongyeeku@163.com
17 * @version 1.0
18 */
19
20 @WebFilter(filterName="log"
21 ,urlPatterns={"/*"})
22 public class LogFilter implements Filter
23 {
24 // FilterConfig可用于访问Filter的配置信息
25 private FilterConfig config;
26 // 实现初始化方法
27 public void init(FilterConfig config)
28 {
29 this.config = config;
30 }
31 // 实现销毁方法
32 public void destroy()
33 {
34 this.config = null;
35 }
36 // 执行过滤的核心方法
37 public void doFilter(ServletRequest request,
38 ServletResponse response, FilterChain chain)
39 throws IOException,ServletException
40 {
41 // ---------下面代码用于对用户请求执行预处理---------
42 // 获取ServletContext对象，用于记录日志
43 ServletContext context = this.config.getServletContext();
44 long before = System.currentTimeMillis();
45 System.out.println("开始过滤...");
46 // 将请求转换成HttpServletRequest请求
47 HttpServletRequest hrequest = (HttpServletRequest)request;
48 // 输出提示信息
49 System.out.println("Filter已经截获到用户的请求的地址： " +
50 hrequest.getServletPath());
51 // Filter只是链式处理，请求依然放行到目的地址
52 chain.doFilter(request, response);
53 // ---------下面代码用于对服务器响应执行后处理---------
54 long after = System.currentTimeMillis();
55 // 输出提示信息
56 System.out.println("过滤结束");
57 // 输出提示信息
58 System.out.println("请求被定位到" + hrequest.getRequestURI() +
59 " 所花的时间为: " + (after - before));
60 }
61 }
