Java.util.logger new file every day

Question

I am using java.util.logging framework to implement registration in my JSF application. I successfully completed this, but, nevertheless, I have a new requirement to rotate the logs and create a new log file for each day.

I can’t understand how this can be implemented. Any hints of implementation would be much appreciated. Thanks.

Here's how I set up my registrar:

myLogger = Logger.getLogger("info.aio"); fileHandler = new FileHandler("aioinfo.log", 1048576, 100, true); fileHandler.setFormatter(new SimpleFormatter()); myLogger.addHandler(fileHandler); 

Answer 1

Since you are using the code to configure FileHandler, you can add code to close and recreate the FileHandler using "% g".

 public static void main(String[] args) throws Exception { //create aioinfo0.log. install(); //rename aioinfo0.log to aioinfo1.log and create aioinfo0.log. install(); } private static final Logger myLogger = Logger.getLogger("info.aio"); private static volatile FileHandler fileHandler; private static void install() throws IOException { FileHandler fh = fileHandler; if (fh != null) { myLogger.removeHandler(fh); fh.close(); //Release any file lock. } fileHandler = rotate("aioinfo%g.log", 1048576, 100, true); fileHandler.setFormatter(new SimpleFormatter()); myLogger.addHandler(fileHandler); } private static FileHandler rotate(String pattern, int limit, int count, boolean append) throws IOException { if (pattern == null) { LogManager m = LogManager.getLogManager(); String p = FileHandler.class.getName(); pattern = m.getProperty(p + ".pattern"); if (pattern == null) { pattern = "%h/java%u.log"; } } new FileHandler(pattern, 0, count, false).close(); //Trigger rotate. return new FileHandler(pattern, limit, count, append); } 

If you want it to work automatically, you can simply create a proxy handler for FileHandler to handle closing and re-creating files every day.

Answer 2

Java.util.logging does not support rotation on a daily basis, see this bug report: http://bugs.java.com/bugdatabase/view_bug.do?bug_id=6350749

Alternatively, you can use logback, log4j or log4j2 and slf4j for the JUL tunnel (see http://www.slf4j.org/legacy.html#jul-to-slf4j ). All mentioned structures support date-based file rotation.

HTH, Mark

Answer 3

Create a task that runs every day at midnight using the ScheduledThreadPoolExecutor, and in the task, delete and close the current FileHandler, and then create a new one with the updated file name.

Something like this should work:

 public class DailyLogger { private static Logger logger; private static FileHandler fh; public static Logger getLogger() { if(logger == null){ initLogger(); ScheduledThreadPoolExecutor sch = (ScheduledThreadPoolExecutor)Executors.newScheduledThreadPool(1); // Create a task for one-shot execution using schedule() Runnable renameLoggerFile = new Runnable(){ // int countRuns = 0; // For testing only @Override public void run() { fh.flush(); fh.close(); try { fh = createFilehandler(new java.sql.Date(System.currentTimeMillis()).toString()); // fh = createFilehandler(new java.sql.Date(System.currentTimeMillis()).toString()+"_"+countRuns++); // for testing SimpleFormatter formatter = new SimpleFormatter(); fh.setFormatter(formatter); logger.addHandler(fh); logger.warning("Runnable executed, new FileHandler is in use!"); } catch (SecurityException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } }; Calendar c = Calendar.getInstance(); long now = c.getTimeInMillis(); c.set(Calendar.HOUR_OF_DAY, 0); c.set(Calendar.MINUTE, 0); c.set(Calendar.SECOND, 0); c.set(Calendar.MILLISECOND, 0); long passed = now - c.getTimeInMillis(); long secondsPassedToday = passed / 1000; long secondsInDay = 86400; TimeUnit timeUnit = TimeUnit.SECONDS; // sch.scheduleAtFixedRate(renameLoggerFile, 5, 10, timeUnit); // for testing long initialDelay = secondsInDay - secondsPassedToday; long relaunchPeriod = secondsInDay; sch.scheduleAtFixedRate(renameLoggerFile, initialDelay, relaunchPeriod, timeUnit); } return logger; } private static FileHandler createFilehandler(String dateForName) throws SecurityException, IOException{ String folder = "log"; File fileFolder = new File(folder); // Create folder log if it doesn't exist if(!fileFolder.exists()){ fileFolder.mkdirs(); } dateForName = folder + File.separator + dateForName + ".log"; boolean appendToFile = true; return new FileHandler(dateForName, appendToFile); } private static void initLogger(){ String folder = "log"; File fileFolder = new File(folder); // Create folder "log" if it doesn't exist if(!fileFolder.exists()){ fileFolder.mkdirs(); } logger = Logger.getLogger("DailyLogger"); try { // This block configure the logger with handler and formatter boolean appendToFile = true; fh = new FileHandler(folder + File.separator + new java.sql.Date(System.currentTimeMillis()) + ".log", appendToFile); logger.addHandler(fh); SimpleFormatter formatter = new SimpleFormatter(); fh.setFormatter(formatter); // the following statement is used to log any messages logger.info("DailyLogger initialized..."); } catch (SecurityException e) { logger.warning("Problem at initializing logger... " + e.getMessage()); } catch (IOException e) { logger.warning("Problem at initializing logger... " + e.getMessage()); } } }