How can I get log4j to delete old rotating log files

Question

How can I get log4j to delete old rotating log files   I know I can set up automated jobs  cron for UNIX and scheduled task for Windows   but I want it cross platform  and I want it in our application s log configuration as a part of our application  rather than in separate code outside in OS specific scripting languages   Our application is not written in OS scripting languages  and I don t want to do this part of it in them

User · Answer

Logs rotate for a reason  so that you only keep so many log files around  In log4j xml you can add this to your  node    lt param name  MaxBackupIndex  value  20   gt    The value tells log4j xml to only keep 20 rotated log files around  You can limit this to 5 if you want or even 1  If your application isn t logging that much data  and you have 20 log files spanning the last 8 months  but you only need a weeks worth of logs  then I think you need to tweak your log4j xml  MaxBackupIndex  and  MaxFileSize  params   Alternatively  if you are using a properties file  instead of the xml  and wish to save 15 files  for example   log4j appender  appenderName  MaxBackupIndex   15

User · Answer

RollingFileAppender does this  You just need to set maxBackupIndex to the highest value for the backup file

User · Answer

There is no default value to control deleting old log files created by DailyRollingFileAppender  But you can write your own custom Appender that deletes old log files in much the same way as setting maxBackupIndex does for RollingFileAppender   Simple instructions found here  From 1    If you are trying to use the Apache Log4J DailyRollingFileAppender for a daily log file  you may need to want to specify the maximum number of files which should be kept  Just like rolling RollingFileAppender supports maxBackupIndex  But the current version of Log4j  Apache log4j 1 2 16  does not provide any mechanism to delete old log files if you are using DailyRollingFileAppender  I tried to make small modifications in the original version of DailyRollingFileAppender to add maxBackupIndex property  So  it would be possible to clean up old log files which may not be required for future usage

User · Answer

You can achieve it using custom log4j appender    MaxNumberOfDays - possibility to set amount of days of rotated log files  CompressBackups - possibility to archive old logs with zip extension   package com example package   import org apache log4j FileAppender  import org apache log4j Layout  import org apache log4j helpers LogLog  import org apache log4j spi LoggingEvent   import java io File  import java io FileFilter  import java io FileInputStream  import java io FileOutputStream  import java io IOException  import java nio file Files  import java text SimpleDateFormat  import java util Calendar  import java util Date  import java util GregorianCalendar  import java util Locale  import java util Optional  import java util TimeZone  import java util zip ZipEntry  import java util zip ZipOutputStream   public class CustomLog4jAppender extends FileAppender        private static final int TOP OF TROUBLE   -1      private static final int TOP OF MINUTE   0      private static final int TOP OF HOUR   1      private static final int HALF DAY   2      private static final int TOP OF DAY   3      private static final int TOP OF WEEK   4      private static final int TOP OF MONTH   5       private String datePattern       yyyy-MM-dd       private String compressBackups    false       private String maxNumberOfDays    7       private String scheduledFilename      private long nextCheck   System currentTimeMillis   - 1      private Date now   new Date        private SimpleDateFormat sdf      private RollingCalendar rc   new RollingCalendar         private static final TimeZone gmtTimeZone   TimeZone getTimeZone  GMT         public CustomLog4jAppender                public CustomLog4jAppender Layout layout  String filename  String datePattern  throws IOException           super layout  filename  true           this datePattern   datePattern          activateOptions               public void setDatePattern String pattern            datePattern   pattern             public String getDatePattern             return datePattern              Override     public void activateOptions             super activateOptions            if  datePattern    null  amp  amp  fileName    null                now setTime System currentTimeMillis                 sdf   new SimpleDateFormat datePattern               int type   computeCheckPeriod                printPeriodicity type               rc setType type               File file   new File fileName               scheduledFilename   fileName   sdf format new Date file lastModified                else               LogLog error  Either File or DatePattern options are not set for appender      name                               private void printPeriodicity int type            String appender    Log4J Appender             switch  type                case TOP OF MINUTE                  LogLog debug appender   name     to be rolled every minute                     break              case TOP OF HOUR                  LogLog debug appender   name     to be rolled on top of every hour                     break              case HALF DAY                  LogLog debug appender   name     to be rolled at midday and midnight                     break              case TOP OF DAY                  LogLog debug appender   name     to be rolled at midnight                     break              case TOP OF WEEK                  LogLog debug appender   name     to be rolled at start of week                     break              case TOP OF MONTH                  LogLog debug appender   name     to be rolled at start of every month                     break              default                  LogLog warn  Unknown periodicity for appender      name                               private int computeCheckPeriod             RollingCalendar rollingCalendar   new RollingCalendar gmtTimeZone  Locale ENGLISH           Date epoch   new Date 0           if  datePattern    null                for  int i   TOP OF MINUTE  i  lt   TOP OF MONTH  i                      SimpleDateFormat simpleDateFormat   new SimpleDateFormat datePattern                   simpleDateFormat setTimeZone gmtTimeZone                   String r0   simpleDateFormat format epoch                   rollingCalendar setType i                   Date next   new Date rollingCalendar getNextCheckMillis epoch                    String r1   simpleDateFormat format next                   if   r0 equals r1                         return i                                                    return TOP OF TROUBLE             private void rollOver   throws IOException           if  datePattern    null                errorHandler error  Missing DatePattern option in rollOver                   return                    String datedFilename   fileName   sdf format now           if  scheduledFilename equals datedFilename                 return                    this closeFile            File target   new File scheduledFilename           if  target exists                  Files delete target toPath                       File file   new File fileName           boolean result   file renameTo target           if  result                LogLog debug fileName     - gt      scheduledFilename             else               LogLog error  Failed to rename      fileName      to      scheduledFilename                            try               this setFile fileName  false  this bufferedIO  this bufferSize             catch  IOException e                errorHandler error  setFile     fileName      false  call failed                       scheduledFilename   datedFilename              Override     protected void subAppend LoggingEvent event            long n   System currentTimeMillis            if  n  gt   nextCheck                now setTime n               nextCheck   rc getNextCheckMillis now               try                   cleanupAndRollOver                  catch  IOException ioe                    LogLog error  cleanupAndRollover   failed    ioe                                   super subAppend event              public String getCompressBackups             return compressBackups             public void setCompressBackups String compressBackups            this compressBackups   compressBackups             public String getMaxNumberOfDays             return maxNumberOfDays             public void setMaxNumberOfDays String maxNumberOfDays            this maxNumberOfDays   maxNumberOfDays             protected void cleanupAndRollOver   throws IOException           File file   new File fileName           Calendar cal   Calendar getInstance            int maxDays   7          try               maxDays   Integer parseInt getMaxNumberOfDays               catch  Exception e                   just leave it at 7                    cal add Calendar DATE  -maxDays           Date cutoffDate   cal getTime            if  file getParentFile   exists                  File   files   file getParentFile   listFiles new StartsWithFileFilter file getName    false                int nameLength   file getName   length                for  File value   Optional ofNullable files  orElse new File 0                      String datePart                  try                       datePart   value getName   substring nameLength                       Date date   sdf parse datePart                       if  date before cutoffDate                             Files delete value toPath                           else if  getCompressBackups   equalsIgnoreCase  YES      getCompressBackups   equalsIgnoreCase  TRUE                              zipAndDelete value                                           catch  Exception pe                           This isn t a file we should touch  it isn t named correctly                                                    rollOver               private void zipAndDelete File file  throws IOException           if   file getName   endsWith   zip                  File zipFile   new File file getParent    file getName       zip                try  FileInputStream fis   new FileInputStream file                    FileOutputStream fos   new FileOutputStream zipFile                    ZipOutputStream zos   new ZipOutputStream fos                     ZipEntry zipEntry   new ZipEntry file getName                     zos putNextEntry zipEntry                   byte   buffer   new byte 4096                   while  true                        int bytesRead   fis read buffer                       if  bytesRead    -1                            break                        else                           zos write buffer  0  bytesRead                                                           zos closeEntry                              Files delete file toPath                          class StartsWithFileFilter implements FileFilter           private String startsWith          private boolean inclDirs           StartsWithFileFilter String startsWith  boolean includeDirectories                super                this startsWith   startsWith toUpperCase                inclDirs   includeDirectories                     public boolean accept File pathname                if   inclDirs  amp  amp  pathname isDirectory                      return false                else                   return pathname getName   toUpperCase   startsWith startsWith                                      class RollingCalendar extends GregorianCalendar           private static final long serialVersionUID   -3560331770601814177L           int type   CustomLog4jAppender TOP OF TROUBLE           RollingCalendar                 super                       RollingCalendar TimeZone tz  Locale locale                super tz  locale                      void setType int type                this type   type                     long getNextCheckMillis Date now                return getNextCheckDate now  getTime                       Date getNextCheckDate Date now                this setTime now                switch  type                    case CustomLog4jAppender TOP OF MINUTE                      this set Calendar SECOND  0                       this set Calendar MILLISECOND  0                       this add Calendar MINUTE  1                       break                  case CustomLog4jAppender TOP OF HOUR                      this set Calendar MINUTE  0                       this set Calendar SECOND  0                       this set Calendar MILLISECOND  0                       this add Calendar HOUR OF DAY  1                       break                  case CustomLog4jAppender HALF DAY                      this set Calendar MINUTE  0                       this set Calendar SECOND  0                       this set Calendar MILLISECOND  0                       int hour   get Calendar HOUR OF DAY                       if  hour  lt  12                            this set Calendar HOUR OF DAY  12                         else                           this set Calendar HOUR OF DAY  0                           this add Calendar DAY OF MONTH  1                                             break                  case CustomLog4jAppender TOP OF DAY                      this set Calendar HOUR OF DAY  0                       this set Calendar MINUTE  0                       this set Calendar SECOND  0                       this set Calendar MILLISECOND  0                       this add Calendar DATE  1                       break                  case CustomLog4jAppender TOP OF WEEK                      this set Calendar DAY OF WEEK  getFirstDayOfWeek                         this set Calendar HOUR OF DAY  0                       this set Calendar MINUTE  0                       this set Calendar SECOND  0                       this set Calendar MILLISECOND  0                       this add Calendar WEEK OF YEAR  1                       break                  case CustomLog4jAppender TOP OF MONTH                      this set Calendar DATE  1                       this set Calendar HOUR OF DAY  0                       this set Calendar MINUTE  0                       this set Calendar SECOND  0                       this set Calendar MILLISECOND  0                       this add Calendar MONTH  1                       break                  default                      throw new IllegalStateException  Unknown periodicity type                               return getTime                            And use this properties in your log4j config file   log4j appender  appenderName  com example package CustomLog4jAppender log4j appender  appenderName  File  logs app-daily log log4j appender  appenderName  Append true log4j appender  appenderName  encoding UTF-8 log4j appender  appenderName  layout org apache log4j EnhancedPatternLayout log4j appender  appenderName  layout ConversionPattern  -5 5p  d  C 1   -  m n log4j appender  appenderName  DatePattern    yyyy-MM-dd log4j appender  appenderName  MaxNumberOfDays 7 log4j appender  appenderName  CompressBackups true

[log4j] How can I get log4j to delete old rotating log files?

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