log4j，日志多个文件输出-优快云博客

本文介绍如何使用Log4j配置多个日志文件，包括不同类型的日志输出到不同的文件夹，并通过示例代码展示了如何指定每个日志文件的路径及格式。

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今天配置了log4j中写多个文件的内容，配置了半天才搞出来，为了避免类似问题，写个博客吧。

首先说一下需求，每天要在7个文件夹中生成文件，文件格式为xxx.log.2000.01.01，自己开发个写文件工具也不是不可以，但是一想log4j有现成的功能，何乐而不为呢，思想胜于一切。所以需要一个logger对应一个文件，开始配置，我定义了7个rootLogger，分别是

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charge_log, gold_log, prop_log, register_log, active_log, game_play_log, online_log
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</pre><pre name="code" class="plain">timer_log是错误日志记录。
下面是我的配置文件：

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log4j.rootLogger=INFO,stdout, timer_log, charge_log, gold_log, prop_log, register_log, active_log, game_play_log, online_log

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

log4j.appender.timer_log=org.apache.log4j.DailyRollingFileAppender
log4j.appender.timer_log.Append=true
log4j.appender.timer_log.DatePattern='.'yyyy-MM-dd
log4j.appender.timer_log.File=../logs/timer/timer.log
log4j.appender.timer_log.Threshold=INFO
log4j.appender.timer_log.layout=org.apache.log4j.PatternLayout
log4j.appender.timer_log.layout.ConversionPattern=%d - %c [%t] %-5p %c %x %l - %m%n

log4j.logger.charge_log=INFO, charge_log
log4j.appender.charge_log=org.apache.log4j.DailyRollingFileAppender
log4j.appender.charge_log.Append=true
log4j.appender.charge_log.DatePattern='.'yyyy-MM-dd
log4j.appender.charge_log.File=../logs/charge_log/charge.log
log4j.appender.charge_log.Threshold=INFO
log4j.appender.charge_log.layout=org.apache.log4j.PatternLayout
log4j.appender.charge_log.layout.ConversionPattern=%m%n
log4j.additivity.charge_log=false

log4j.logger.gold_log=INFO, gold_log
log4j.appender.gold_log=org.apache.log4j.DailyRollingFileAppender
log4j.appender.gold_log.Append=true
log4j.appender.gold_log.DatePattern='.'yyyy-MM-dd
log4j.appender.gold_log.File=../logs/gold_log/gold_log.log
log4j.appender.gold_log.Threshold=INFO
log4j.appender.gold_log.layout=org.apache.log4j.PatternLayout
log4j.appender.gold_log.layout.ConversionPattern=%m%n
log4j.additivity.gold_log=false

log4j.logger.prop_log=INFO, prop_log
log4j.appender.prop_log=org.apache.log4j.DailyRollingFileAppender
log4j.appender.prop_log.Append=true
log4j.appender.prop_log.DatePattern='.'yyyy-MM-dd
log4j.appender.prop_log.File=../logs/prop_log/prop_log.log
log4j.appender.prop_log.Threshold=INFO
log4j.appender.prop_log.layout=org.apache.log4j.PatternLayout
log4j.appender.prop_log.layout.ConversionPattern=%m%n
log4j.additivity.prop_log=false

log4j.logger.register_log=INFO, register_log
log4j.appender.register_log=org.apache.log4j.DailyRollingFileAppender
log4j.appender.register_log.Append=true
log4j.appender.register_log.DatePattern='.'yyyy-MM-dd
log4j.appender.register_log.File=../logs/register_log/register_log.log
log4j.appender.register_log.Threshold=INFO
log4j.appender.register_log.layout=org.apache.log4j.PatternLayout
log4j.appender.register_log.layout.ConversionPattern=%m%n
log4j.additivity.register_log=false

log4j.logger.active_log=INFO, active_log
log4j.appender.active_log=org.apache.log4j.DailyRollingFileAppender
log4j.appender.active_log.Append=true
log4j.appender.active_log.DatePattern='.'yyyy-MM-dd
log4j.appender.active_log.File=../logs/active_log/active_log.log
log4j.appender.active_log.Threshold=INFO
log4j.appender.active_log.layout=org.apache.log4j.PatternLayout
log4j.appender.active_log.layout.ConversionPattern=%m%n
log4j.additivity.active_log=false

log4j.logger.game_play_log=INFO, game_play_log
log4j.appender.game_play_log=org.apache.log4j.DailyRollingFileAppender
log4j.appender.game_play_log.Append=true
log4j.appender.game_play_log.DatePattern='.'yyyy-MM-dd
log4j.appender.game_play_log.File=../logs/game_play_log/game_play_log.log
log4j.appender.game_play_log.Threshold=INFO
log4j.appender.game_play_log.layout=org.apache.log4j.PatternLayout
log4j.appender.game_play_log.layout.ConversionPattern=%m%n
log4j.additivity.game_play_log=false

log4j.logger.online_log=INFO, online_log
log4j.appender.online_log=org.apache.log4j.DailyRollingFileAppender
log4j.appender.online_log.Append=true
log4j.appender.online_log.DatePattern='.'yyyy-MM-dd
log4j.appender.online_log.File=../logs/online_log/online_log.log
log4j.appender.online_log.Threshold=INFO
log4j.appender.online_log.layout=org.apache.log4j.PatternLayout
log4j.appender.online_log.layout.ConversionPattern=%m%n
log4j.additivity.online_log=false

配置文件中有几个关键点：
1.log4j.logger.online_log=INFO, online_log

2.log4j.additivity.online_log=false

additivity的含义是子Logger 是否继承父Logger 的输出源（appender）的标志位。具体说，默认情况下子Logger 会继承父Logger 的appender，也就是说子Logger 会在父Logger 的appender里输出。若是additivity设为false，则子Logger 只会在自己的appender里输出，而不会在父Logger 的appender里输出。

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ConversionPattern=%m%n 是我只输出我的内容加个换行。
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</pre><pre name="code" class="plain">测试代码如下：
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<pre name="code" class="java">import java.util.List;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class TestObservable {

Logger chargeLogger = LoggerFactory.getLogger("charge_log");
Logger goldLogger = LoggerFactory.getLogger("gold_log");
Logger propLogger = LoggerFactory.getLogger("prop_log");
Logger registerLogger = LoggerFactory.getLogger("register_log");
Logger activeLogger = LoggerFactory.getLogger("active_log");
Logger gamePlayLogger = LoggerFactory.getLogger("game_play_log");
Logger onlineLogger = LoggerFactory.getLogger("online_log");


public void setSource(List<?> objectList,LoggerType loggerType) throws Exception {

if(objectList == null || objectList.isEmpty()) {
return;
}

for(Object obj : objectList) {

switch(loggerType) {
case CHARGE_LOG :
chargeLogger.info(obj.toString());
break;
case ACTIVE_ACCOUNT :
activeLogger.info(obj.toString());
break;
case GAME_PLAY :
gamePlayLogger.info(obj.toString());
break;
case GOLD_LOG :
goldLogger.info(obj.toString());
break;
case ONLINE_PLAYER :
onlineLogger.info(obj.toString());
break;
case PROP_LOG :
propLogger.info(obj.toString());
break;
case REGISTER_LOG :
registerLogger.info(obj.toString());
break;
default :
throw new Exception("Type not suitable.");
}
}
}

public void setSource(Object obj,LoggerType loggerType) throws Exception {

if(obj == null) {
return;
}

switch(loggerType) {
case CHARGE_LOG :
chargeLogger.info(obj.toString());
break;
case ACTIVE_ACCOUNT :
activeLogger.info(obj.toString());
break;
case GAME_PLAY :
gamePlayLogger.info(obj.toString());
break;
case GOLD_LOG :
goldLogger.info(obj.toString());
break;
case ONLINE_PLAYER :
onlineLogger.info(obj.toString());
break;
case PROP_LOG :
propLogger.info(obj.toString());
break;
case REGISTER_LOG :
registerLogger.info(obj.toString());
break;
default :
throw new Exception("Type not suitable.");
}
}

public static void main(String[] args) {
<pre name="code" class="plain"> TestObservable abservable = new TestObservable();
try {abservable.setSource("gole_log", LoggerType.GOLD_LOG);abservable.setSource("charge_log", LoggerType.CHARGE_LOG);abservable.setSource("active_log", LoggerType.ACTIVE_ACCOUNT);abservable.setSource("game_play_log", LoggerType.GAME_PLAY);abservable.setSource("online_player", LoggerType.ONLINE_PLAYER);abservable.setSource("prop_log", LoggerType.PROP_LOG);abservable.setSource("register_log", LoggerType.REGISTER_LOG);} catch (Exception e) {e.printStackTrace();}}}