Log4j 的使用

1.下载

http://logging.apache.org/log4j/1.2/

2.工程

3.详解

1）代码中使用

package com.wicresoft.demo;

import java.util.Properties;
import org.apache.log4j.Logger;
import org.apache.log4j.PropertyConfigurator;

public class Hello {

	Logger logger = Logger.getLogger(Hello.class);
	
	public Hello(){
		logger.warn("Hello constructed.");
		logger.warn("Hello constructed.");
	}
	
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		PropertyConfigurator.configure("log4j.properties");
		//initLog4j();
		Hello hello = new Hello();
	}
	
	/*
	 * Initialize configuration of log4j
	 * you do not need file log4j.properties
	 * */
	private static void initLog4j() {
		Properties prop = new Properties();
		prop.setProperty("log4j.rootLogger", "DEBUG, CONSOLE");
		prop.setProperty("log4j.appender.CONSOLE", "org.apache.log4j.ConsoleAppender");
		prop.setProperty("log4j.appender.CONSOLE.layout", "org.apache.log4j.PatternLayout");
		prop.setProperty("log4j.appender.CONSOLE.layout.ConversionPattern", "%d{HH:mm:ss,SSS} [%t] %-5p %C{1} : %m%n");
		PropertyConfigurator.configure(prop);
	}
}

2）配置文件

log4j.rootLogger=info, ServerDailyRollingFile, stdout 
log4j.appender.ServerDailyRollingFile=org.apache.log4j.DailyRollingFileAppender 
log4j.appender.ServerDailyRollingFile.DatePattern='.'yyyy-MM-dd 
log4j.appender.ServerDailyRollingFile.File=C\://logs/notify-subscription.log 
log4j.appender.ServerDailyRollingFile.layout=org.apache.log4j.PatternLayout 
log4j.appender.ServerDailyRollingFile.layout.ConversionPattern=%d - %m%n 
log4j.appender.ServerDailyRollingFile.Append=true
log4j.appender.stdout=org.apache.log4j.ConsoleAppender 
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout 
log4j.appender.stdout.layout.ConversionPattern=%d{yyyy-MM-dd HH\:mm\:ss} %p [%c] %m%n

4.输出

5.问题解决

如果报文件找不到异常,则文件路径不对，bin目录应使用

PropertyConfigurator.configure("/bin/log4j.properties");

通常放在项目的根目录下