log4j的容易学习

log4j的简单学习

1.LOG4J的配置：采用log4j.properties文件

log4j.rootCategory=warn,A1
log4j.appender.A1=org.apache.log4j.DailyRollingFileAppender

#log4j.appender.A1=org.apache.log4j.RollingFileAppender
log4j.appender.A1.File=? 日志文件的路径

#log4j.appender.A1.MaxFileSize=1024KB
#log4j.appender.A1.MaxBackupIndex=1
log4j.appender.A1.layout=org.apache.log4j.PatternLayout
log4j.appender.A1.layout.ConversionPattern=%-5p: %c{2}? %d{yyyy-MM-dd HH:mm:ss} %m%n

log4j.logger.log=debug

?

2.LOG4J的初始化：用一个Servlet来实现它的初始化

package servlet;

import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;

import org.apache.log4j.PropertyConfigurator;

public class Log4jInit extends HttpServlet
{
?public void init() throws ServletException
?{?
??// 从Servlet参数读取log4j的配置文件
??PropertyConfigurator.configure(Log4jInit.class.getResource("log4j.properties"));
?}

?public void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException, ServletException
?{
?}

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

?web.xml中增加：

<servlet>
??<servlet-name>Log4jInit</servlet-name>
??<servlet-class>servlet.Log4jInit</servlet-class>
??<init-param>
???<param-name>log4j-config-file</param-name>
???<param-value>log4j.properties</param-value>
??</init-param>
??<load-on-startup>1</load-on-startup>

?</servlet>

3.使用LOG4J:

package log;

import org.apache.log4j.*;

public class Log
{
?
?private Logger log = Logger.getLogger(Log.class);
?
?public void testLog()
?{
??try
??{
???log.info("info test");
???log.warn("warn test");
??}
??catch (Exception e)
??{
???e.printStackTrace();
??}
?}
?
}