在log4j中使用FileNamePattern，RollingFileAppender

Question

I have a log file named app.log. When it rolls over (I'm setting it to every minute just for testing purposes), I would like it to be renamed to app-YYYY-MM-dd_HH-mm.log but it's not working. Below is my log4j settings:

log4j.appender.myLog=org.apache.log4j.RollingFileAppender
log4j.appender.myLog.rollingPolicy=TimeBasedRollingPolicy
log4j.appender.myLog.File=logs/app.log
log4j.appender.myLog.rollingPolicy.FileNamePattern=logs/app-%d{yyyy-MM-dd_HH-mm}.log
log4j.appender.myLog.Append=true
log4j.appender.myLog.layout=org.apache.log4j.PatternLayout
log4j.appender.myLog.layout.ConversionPattern=%d %-5p [%t] %-17c{2} (%13F:%L) %3x - %m%n

Does anyone know what's the problem? During the rollover, it just renames the file into app.log.1 .

Answer 1

I assume you're using just log4j. Version 1.2.16 is the newest one. rollingPolicy doesn't exist in its source code; only in log4j.dtd file for xml based configuration.

The only way you'll get what you want to work is to download Apache extras companion for log4j .

---

Eventually if you don't want to use extras You can workaround using:

org.apache.log4j.DailyRollingFileAppender

Minus of this path is that your log files won't be gzipped.

Answer 2

According to the log4j wiki :

Note that TimeBasedRollingPolicy can only be configured with xml, not log4j.properties

The API doesn't mention that, but perhaps that's the problem?

Answer 3

Download log4j extras jar file and put it into lib folder. Also add the rollingPolicy tag a follows:

<rollingPolicy class="org.apache.log4j.rolling.TimeBasedRollingPolicy">
    <param name="FileNamePattern" 
       value="D:/Apps/Enterprise_domain/diagnostics/logs/diagnostics.% d{yyyy-MM-dd_HH-mm}.log"/>
</rollingPolicy>

Answer 4

Please check you have included apache-log4j-extras.jar and using log4j-1.2.16.jar or at least above 2.17 version. here is sample log4j.properties which can be used.

    #Worked with 2.17 version
    #make log files rotate every minute or hour and zip old rotated logs
    log4j.rootLogger=INFO, loggerId
    log4j.appender.loggerId=org.apache.log4j.rolling.RollingFileAppender
    log4j.appender.loggerId.rollingPolicy=org.apache.log4j.rolling.TimeBasedRollingPolicy
    log4j.appender.loggerId.rollingPolicy.ActiveFileName=worker.log
    log4j.appender.loggerId.rollingPolicy.FileNamePattern=worker-.%d{yyyyMMdd-HHmm}.log.gz
    log4j.appender.loggerId.layout=org.apache.log4j.PatternLayout
    log4j.appender.loggerId.layout.ConversionPattern=%d [%t] %-5p (%F:%L) - %m%n

for more details on properties please check here

Answer 5

Try removing logs/ from both .File and .FileNamePattern . I'm reading the code, and it looks like it should work, but it may be worth reducing the problem.

https://svn.apache.org/repos/asf/logging/log4j/companions/extras/trunk/src/main/java/org/apache/log4j/rolling/TimeBasedRollingPolicy.java

Answer 6

System.out.println("Loggers initiallization process started..");
 if(objApploger == null){
     objApploger = new AppLogger();
     String loglevel="ERROR";
     String logPath="E:\\Examples\\applicationLogs";
     String logMaxSize="50000";//in kbs
     int nmaxbackupIndex=20;
     String conversionPattern="%d{yyyy-MM-dd HH:mm:ss:SSS} %-5p  :: %m%n";       
     RollingFileAppender RFAppender= null;
     RFLog =Logger.getLogger("Log");
     RFLog.setLevel(Level.toLevel(loglevel));       
     Calendar cal= Calendar.getInstance();       
     String timeFrame=cal.get(5)+"_"+(cal.get(2)+1)+"_"+cal.get(1);
     logPath=logPath+"TestLog_"+timeFrame+".log";
     RFAppender = new RollingFileAppender(new PatternLayout(conversionPattern),logPath);
     RFAppender.setMaxBackupIndex(nmaxbackupIndex);
     RFAppender.setMaxFileSize(logMaxSize);
     RFLog.addAppender(RFAppender);
     System.out.println("Loggers initiallization process completed..");      
 }