Logger

/LogTest/src/log4j.properties

log4j.rootLogger=INFO,FILE
log4j.addivity.org.apache=true
log4j.appender.FILE=org.apache.log4j.FileAppender
log4j.appender.FILE.File=file.log
log4j.appender.FILE.Append=false
log4j.appender.FILE.layout=org.apache.log4j.PatternLayout
log4j.appender.FILE.layout.ConversionPattern=[%l] %d -%-4r [%t] %-5p %c %x - %m%n


import java.util.Scanner;

import org.apache.log4j.Logger;


public class testLog4 {

public static void main(String[] args){

//获取而不是新建
Logger log = Logger.getLogger(testLog4.class);

Scanner sc = new Scanner(System.in);

int a = sc.nextInt();
int b = sc.nextInt();

log.info("Input a "+a);
log.info("Input b "+b);
try{
System.out.println(a/b);
} catch(ArithmeticException e){
log.error("/ by zero");
}

int c = a+b;
log.info("Sum up "+c);

//log.debug("debug...");
//log.info("info...");
//log.error("error...");
}

}


[testLog4.main(testLog4.java:18)] 2012-04-05 09:12:17,378 -0    [main] INFO  testLog4  - Input a 3
[testLog4.main(testLog4.java:19)] 2012-04-05 09:12:17,389 -11   [main] INFO  testLog4  - Input b 0
[testLog4.main(testLog4.java:23)] 2012-04-05 09:12:17,396 -18   [main] ERROR testLog4  - / by zero
[testLog4.main(testLog4.java:27)] 2012-04-05 09:12:17,396 -18   [main] INFO  testLog4  - Sum up 3