filterservlet.java

一个javaweb开的小例子

package cn.com.pkusoft.web;

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.HttpServlet;

import org.apache.log4j.Logger;
import org.apache.log4j.xml.DOMConfigurator;


/**
 * 过滤SERVLET，用来设置一些特殊的操作，如转码，开始LOG4G等
 * <p>Title: </p>
 * <p>Description: </p>
 * <p>Copyright: Copyright (c) 2004</p>
 * <p>Company: </p>
 * @author not attributable
 * @version 1.0
 */
public class FilterServlet extends HttpServlet implements Filter
{
    private FilterConfig filterConfig;
    private static Logger logger_ = Logger.getLogger(FilterServlet.class);
    private boolean bInitLog = true;

    //Handle the passed-in FilterConfig
    public void init(FilterConfig filterConfig) throws ServletException
    {
        this.filterConfig = filterConfig;
    }

    //Process the request/response pair
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain)
    {
        try
        {
            /*if (this.bInitLog)
            {
                System.out.println("this is first visit, then we do the initial log4j");
                //DOMConfigurator.configure("G:\\src\\java\\PkuNet\\config\\configLog4j.xml");
                DOMConfigurator.configure("D:\\PkuNet\\config\\configLog4j.xml");

                this.bInitLog = false;
            }

            logger_.debug("here is debug");
            logger_.info("here is info");
            logger_.warn("here is warn");
            logger_.fatal("here is fatal");*/

            System.out.println("ok!");


            filterChain.doFilter(request, response);
        }
        catch(ServletException sx)
        {
            filterConfig.getServletContext().log(sx.getMessage());
        }
        catch(IOException iox)
        {
            filterConfig.getServletContext().log(iox.getMessage());
        }
    }

    //Clean up resources
    public void destroy()
    {
    }
}