Filter也可以日志记录，在request 之前后， 该filter 使用Apache 日只记录工具，记录客户IP ,访问URI 以及消耗时间。

LogFilter.java

package com.helloweenvsfei.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;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

public class LogFilter implements Filter {

    private Log log = LogFactory.getLog(this.getClass());

    private String filterName;

    public void init(FilterConfig config) throws ServletException {

        // 获取 Filter 的 name，配置在 web.xml 中
        filterName = config.getFilterName();

        log.info("启动 Filter: " + filterName);

    }

    public void doFilter(ServletRequest req, ServletResponse res,
            FilterChain chain) throws IOException, ServletException {

        HttpServletRequest request = (HttpServletRequest) req;
        HttpServletResponse response = (HttpServletResponse) res;

        long startTime = System.currentTimeMillis();
        String requestURI = request.getRequestURI();

        requestURI = request.getQueryString() == null ? requestURI
                : (requestURI + "?" + request.getQueryString());

        chain.doFilter(request, response);

        long endTime = System.currentTimeMillis();

        log.info(request.getRemoteAddr() + " 访问了 " + requestURI + ", 总用时 "
                + (endTime - startTime) + " 毫秒。");

    }

    public void destroy() {
        log.info("关闭 Filter: " + filterName);
    }

}

log4j.properties   使用jar log4j.jar 和 commons-logging.jar

可参考

commmons_logging 和 log4j 之日志笔记一

log4j.rootLogger=INFO, A1

log4j.appender.A1=org.apache.log4j.ConsoleAppender
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=%-d{yyyy-MM-dd HH\:mm\:ss,SSS} [%l]-[%p] %m%n

web.xml

<filter>
    <filter-name>logFilter</filter-name>
    <filter-class>com.helloweenvsfei.filter.LogFilter</filter-class>
</filter>

<filter-mapping>
    <filter-name>logFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

如不需要日志Filter ,可把web.xml 相应注释掉即可。