log4j的简单配置及使用

Posted 2022-11-25 SSimeng

1. 在java项目中引入log4j.jar这个包

• 提取码：q1vy
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2. 在src根目录下创建log4j.properties文件

### 设置###
log4j.rootLogger = debug,stdout,D,E

### 输出信息到控制台 ###
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 = [%-5p] %dyyyy-MM-dd HH:mm:ss,SSS method:%l%n%m%n

### 输出DEBUG 级别以上的日志到=E://logs/error.log ###
log4j.appender.D = org.apache.log4j.DailyRollingFileAppender
log4j.appender.D.File = E://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 = %-dyyyy-MM-dd HH:mm:ss  [ %t:%r ] - [ %p ]  %m%n

### 输出ERROR 级别以上的日志到=E://logs/error.log ###
log4j.appender.E = org.apache.log4j.DailyRollingFileAppender
log4j.appender.E.File =E://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 = %-dyyyy-MM-dd HH:mm:ss  [ %t:%r ] - [ %p ]  %m%n

3. 创建日志工具类:LogUtil.java

import org.apache.log4j.Logger;

public enum LogUtil 
	INSTANCE;
	public void debug(Object msg,Class<?> clazz) 
		Logger.getLogger(clazz).debug(msg);
	
	public void info(Object msg,Class<?> clazz) 
		Logger.getLogger(clazz).info(msg);
	

4. 在项目中使用日志（简单示例）

public class Test 
    private LogUtil logger=LogUtil.INSTANCE; 
    public static void main(String[] args)   
		logger.info("创建数据源成功...", DbUtil.class);
		//此处的e为实际过程中遇到的exception
		logger.debug(e.getMessage(), DbUtil.class);