Log4j2的使用：按时间和大小分割日志，并分包输出

ゝ一纸荒年。 2022-05-14 14:34 256阅读 0赞

1、使用到的jar包

<dependency>
    	<groupId>org.apache.logging.log4j</groupId>
    	<artifactId>log4j-core</artifactId>
    	<version>2.11.0</version>
    </dependency>
    
    <dependency>
    	<groupId>org.apache.logging.log4j</groupId>
    	<artifactId>log4j-api</artifactId>
    	<version>2.11.0</version>
    </dependency>

2、配置文件的设置

将配置文件log4j2.xml放在maven项目的resource路径下。代码如下：

①按时间和大小分割文件

<?xml version="1.0" encoding="UTF-8"?>
    <configuration status="error">
    	
    	<appenders>
    		
    		<RollingFile name="RollingFile" fileName="log4j2/logs/web.log"
    			filePattern="log4j2/logs/$${date:yyyy-MM}/%d{MM-dd-yyyy}-%i.log">
    			
    			<PatternLayout
    				pattern="[ %level{length=1} | %-20class{1} | %-15M | %-2L | %-2t | %X{5} | %d{yyyy-MM-dd HH:mm:ss} ] %msg%n" />
    			<Policies>
    				<TimeBasedTriggeringPolicy interval="2 hour" />			
    				<SizeBasedTriggeringPolicy size="10KB" />		
    			</Policies>
     			<DefaultRolloverStrategy max="20" />   
    		</RollingFile>
    	</appenders>
    	
    	<loggers>
    		
    		<root level="trace">
    			<appender-ref ref="RollingFile" />
    		</root>
    	</loggers>
    </configuration>

②按时间和大小分割，并分包打印日志

<?xml version="1.0" encoding="UTF-8"?>
    <configuration status="error">
    	
    	<appenders>
    		
    		<Console name="Console" target="SYSTEM_OUT">
    			
    			<ThresholdFilter level="debug" onMatch="ACCEPT"
    				onMismatch="DENY" />
    			
    			<PatternLayout
    				pattern="[ %-20class{1} ] %msg%n" />
    		</Console>
    		
    		<RollingFile name="RollingFile-info" fileName="log4j2/info/info.log"
    			filePattern="log4j2/info/$${date:yyyy-MM}/%d{MM-dd-yyyy}-%i.log">
    			
    			<PatternLayout
    				pattern="[ %level{length=1} | %-20class{1} | %-15M | %-2L | %-2t | %X{5} | %d{yyyy-MM-dd HH:mm:ss} ] %msg%n" />
    			<Policies>
    				<TimeBasedTriggeringPolicy interval="2 hour" />			
    				<SizeBasedTriggeringPolicy size="10KB" />		
    			</Policies>
    			<DefaultRolloverStrategy max="20" />   
    		</RollingFile>
    		<RollingFile name="RollingFile-debug" fileName="log4j2/debug/debug.log"
    			filePattern="log4j2/debug/$${date:yyyy-MM}/%d{MM-dd-yyyy}-%i.log">
    			
    			<PatternLayout
    				pattern="[ %level{length=1} | %-20class{1} | %-15M | %-2L | %-2t | %X{5} | %d{yyyy-MM-dd HH:mm:ss} ] %msg%n" />
    			<Policies>
    				<TimeBasedTriggeringPolicy interval="2 hour" />			
    				<SizeBasedTriggeringPolicy size="10KB" />		
    			</Policies>
    			<DefaultRolloverStrategy max="20" />   
    		</RollingFile>
    		<RollingFile name="RollingFile-error" fileName="log4j2/error/error.log"
    			filePattern="log4j2/error/$${date:yyyy-MM}/%d{MM-dd-yyyy}-%i.log">
    			
    			<PatternLayout
    				pattern="[ %level{length=1} | %-20class{1} | %-15M | %-2L | %-2t | %X{5} | %d{yyyy-MM-dd HH:mm:ss} ] %msg%n" />
    			<Policies>
    				<TimeBasedTriggeringPolicy interval="2 hour" />			
    				<SizeBasedTriggeringPolicy size="10KB" />		
    			</Policies>
    			<DefaultRolloverStrategy max="20" />   
    		</RollingFile>
    	</appenders>
    	
    	<loggers>
    		
    		<logger name="com.test.info" level="debug">
    			
    			<appender-ref ref="RollingFile-info"/>
    		</logger>
    		<logger name="com.test.debug" level="debug" >
    			<appender-ref ref="RollingFile-debug"/>
    		</logger>
    		<logger name="com.test.error" level="debug">
    			<appender-ref ref="RollingFile-error"/>
    		</logger>
    		
    		<root level="trace">
    			<appender-ref ref="Console" />
    		</root>
    	</loggers>
    </configuration>

3、在代码中使用

①分别创建包com.test.debug，com.test.info，com.test.error。

②分别在三个包下面创建文件DebugLogging.java，InfoLogging.java，ErrorLogging.java。  
代码如下：

package com.test.debug;
    
    import org.apache.logging.log4j.LogManager;
    import org.apache.logging.log4j.Logger;
    
    public class DebugLogging {
    
    	private static Logger logger = LogManager.getLogger(DebugLogging.class.getName());
    	
    	public static void logMessage() {
    		logger.debug("debug");
    	}
    	
    }

package com.test.error;
    
    import org.apache.logging.log4j.LogManager;
    import org.apache.logging.log4j.Logger;
    
    public class ErrorLogging {
    
    	private static Logger logger = LogManager.getLogger(ErrorLogging.class.getName());
    	
    	public static void logMessage() {
    		logger.error("error");
    	}
    	
    }

package com.test.info;
    
    import org.apache.logging.log4j.LogManager;
    import org.apache.logging.log4j.Logger;
    
    public class InfoLogging {
    
    	private static Logger logger = LogManager.getLogger(InfoLogging.class.getName());
    	
    	public static void logMessage() {
    		logger.info("info");
    	}
    	
    }

③在com.test下创建MainTest.java，代码如下：

package com.test;
    
    import com.test.debug.DebugLogging;
    import com.test.error.ErrorLogging;
    import com.test.info.InfoLogging;
    
    public class MainTest {
    
    	public static void main(String[] args) {
    		DebugLogging.logMessage();
    		ErrorLogging.logMessage();
    		InfoLogging.logMessage();
    	}
    }

④运行结果如下：

log4j2/debug/debug.log:

log4j2/error/error.log:

log4j2/info/info.log:

参考文档：

1、浅谈Log4j和Log4j2的区别：  
https://blog.csdn.net/weixin\_38009266/article/details/78485815

2、Log4j输出格式控制--log4j的PatternLayout参数含义以及详细配置：  
https://blog.csdn.net/reserved\_person/article/details/52849505