timetrackfilter.java

介绍了j2ee开发常用的学习知识,如servlet,javamail,EJB等知识,并有项目源码.

/*
 * TimeTrackFilter.java
 *
 * Created on 2007年10月17日, 下午9:49
 */

package com.servlet;

import java.io.*;
import java.util.*;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;

/**
 *
 * @author  hyl
 * @version
 */

public class TimeTrackFilter implements Filter {
    private FilterConfig filterConfig = null;
    
    public void init(FilterConfig filterConfig) throws ServletException {
        this.filterConfig = filterConfig;
    }
    
    public void destroy() {
        this.filterConfig = null;
    }
    public void doFilter( ServletRequest request, ServletResponse response, FilterChain chain ) throws IOException, ServletException {
        Date startTime, endTime;
        double totalTime;
        StringWriter sw = new StringWriter();
        System.out.println("我在Filter中");
        
        startTime = new Date();
        chain.doFilter(request, response);
        endTime = new Date();
        totalTime = endTime.getTime() - startTime.getTime();
        totalTime = totalTime ;
        System.out.println("我在Filter中");
        PrintWriter writer = new PrintWriter(sw);
        writer.println("===============");
        writer.println("耗时: " + totalTime + " 毫秒" );
        writer.println("===============");
        filterConfig.getServletContext(). log(sw.getBuffer().toString());
    }
}