Log4j配置

log4j.properties

log4j.rootLogger=DEBUG,stdout,r
log4j.appender.stdout=org.apache.log4j.ConsoleAppender //控制台
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p (%F:%L) - %m%n
log4j.appender.r=org.apache.log4j.RollingFileAppender //文件
log4j.appender.r.File=log.txt
log4j.appender.r.MaxFileSize=100KB
log4j.appender.r.MaxBackupIndex=1
log4j.appender.r.layout=org.apache.log4j.PatternLayout
log4j.appender.r.layout.ConversionPattern=%d {YYYY MMM DD HH:mm:ss } %-5p%c - %m%n

测试

package com.log4j;import org.apache.log4j.*;public class Logtest {static Logger l=Logger.getLogger(Logtest.class.getName());public static void main(String[] args) {PropertyConfigurator.configure("src/log4j.properties");l.debug("debug...");l.info("info...");l.warn("warn...");l.error("error...");}}