log4j的初步使用

1、java文件：

import org.apache.log4j.Logger;


public class testLog {

    private static Logger logger = Logger.getLogger(testLog.class);
    //创建一个属于testLog类的日志文件
    
    public static void main(String[] args) {
        // TODO Auto-generated method stub
        //System.out.print("123");
        System.out.println(testLog.class.getName());
        
        logger.debug("this is debug message.");
        logger.info("this is info .");
        logger.error("this is error");
    }

}

 

2、log4j.properties 配置文件主要是修改日志打印的格式，是否打印，是否记录到文件

#### Use one appender to log to console

log4j.rootCategory=DEBUG,stdout,RR
###log4j.rootCategory=OFF,stdout,RR ###就不打印

#### Appender writes to console

log4j.appender.stdout=org.apache.log4j.ConsoleAppender

log4j.appender.stdout.layout=org.apache.log4j.PatternLayout

log4j.appender.stdout.layout.ConversionPattern=%d{yyyy MMM dd HH:mm:ss} %-5p %c - %m%n

#### Appender writes to file

log4j.appender.RR=org.apache.log4j.RollingFileAppender

log4j.appender.RR.File=log12345.txt

log4j.appender.RR.MaxFileSize=100KB

log4j.appender.RR.MaxBackupIndex=1

log4j.appender.RR.layout=org.apache.log4j.PatternLayout

log4j.appender.RR.layout.ConversionPattern=%d{yyyy MMM dd HH:mm:ss} %-5p %c - %m%n

 

参考：http://blog.csdn.net/doodoofish/article/details/17921