log4j在eclipse下使用
1、下载log4j***.jar,放到工程lib文件夹下,并使用add external jars导入工程
2、建立配置文件log4j.properties并写入如下内容:
### set log levels ###
log4j.rootLogger = stdout , D, E
### 输出到控制台 ###
log4j.appender.stdout = org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Threshold = DEBUG
log4j.appender.stdout.Target = System.out
log4j.appender.stdout.layout = org.apache.log4j.SimpleLayout
log4j.appender.stdout.layout.ConversionPattern = %d{ABSOLUTE} %5p %c{ 1 }:%L - %m%n
### 输出到日志文件 ###
log4j.appender.D = org.apache.log4j.DailyRollingFileAppender
log4j.appender.D.File = logs/log.log
log4j.appender.D.Append = true
log4j.appender.D.Threshold = DEBUG
log4j.appender.D.layout = org.apache.log4j.PatternLayout
log4j.appender.D.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss} [ %t:%r ] - [ %p ] %m%n
### 保存异常信息到单独文件 ###
log4j.appender.E = org.apache.log4j.DailyRollingFileAppender
log4j.appender.E.File = logs/error.log
log4j.appender.E.Append = true
log4j.appender.E.Threshold = ERROR
log4j.appender.E.layout = org.apache.log4j.PatternLayout
log4j.appender.E.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss} [ %t:%r ] - [ %p ] %m%n
在程序中如下使用:
import org.apache.log4j.Logger; import org.apache.log4j.PropertyConfigurator; public class Log4JTest { public static void main(String[] args){ PropertyConfigurator.configure("bin/log4j.properties"); Logger console = Logger.getLogger(Log4JTest.class); console.debug("debug"); //!!!!注意,这个不论console上的Threshold怎么设置,都无法输出到console!!!! console.warn("warn"); console.info("info"); console.error("error"); console.fatal("fatal"); } }