Log4j

代码：

package com.logTest;

 

 

import java.io.BufferedReader;

 

import java.io.FileNotFoundException;

 

import java.io.FileReader;

 

import java.io.IOException;

 

import org.apache.log4j.Logger;

 

public class Log4jDemo {

privatestatic Loggerlogger = Logger.getLogger(Log4jDemo.class);

publicstaticvoid main(String[] args) {

String content;

try {

FileReader fileReader = new FileReader("d:\\a.txt");

BufferedReader bufferdReader = new BufferedReader(fileReader);

while((content = bufferdReader.readLine()) !=null){

logger.info(content);

}

} catch (FileNotFoundException e) {

logger.warn("file is not fined!");

//e.printStackTrace();

 

} catch (IOException e) {

logger.warn("read file error!");

//e.printStackTrace();

 

}

}

}

 

 

出现：

 

log4j:WARN No appenders could be found for logger (com.logTest.Log4jDemo).

log4j:WARN Please initialize the log4j system properly.

 

 

解决办法：

log4j.properties文件需要放到web-inf/class目录下面,在eclipse里面放到src目录下面，会自动拷贝到class目录下面去。文件里面的内容如下即可：

 

###set output encoding###

 

log4j.appender.logfile.encoding=UTF-8

 

### set log levels ###

 

log4j.rootLogger = debug,stdout,D,E

 

 

### out print at console ###

 

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

 

log4j.appender.stdout.Target = System.out

 

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

 

log4j.appender.stdout.layout.ConversionPattern = %d{ABSOLUTE}%5p[%c{1}]:%L-%m%n

 

 

### write in log ###

 

log4j.appender.D = org.apache.log4j.DailyRollingFileAppender

 

log4j.appender.D.File = c:/test.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-ddHH:mm:ss}[%t:%r]-[%p]%m%n

 

 

### save error log ###

 

log4j.appender.E = org.apache.log4j.DailyRollingFileAppender

 

log4j.appender.E.File = c:/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-ddHH\:mm\:ss}[%t\:%r]-[%p]%m%n