How to avoid and controll the increment of files app.log.X in JAVA LOGGIN

Question

I am fighting with some thing from yesterday.

I want to log a webapp (WAR) in java.

I create a log, append a FileHandler, and i send log messages. But, like all of us know, the file handler keep the lock over the new file until i call fush() and close(), so, when i redeploy the war (or if i run it in develop, and i continously deploy the app) it create one file per deploy (ugly).

So, I was trying to avoid this behavior, (I am not sure if it is done by a thing of performance this way, maybe open and close file everytime is expensive, i am not sure) but i want to atach the handler and flush/close each time the Logger log a message. (So i have only one file).

But i dont find any way to do this. I try to extends a java.util.Logger class and is so hard... (and -advised against- by some people).

Some one has any clue on how can i aproach this situation?

Thanks in advance!

public class LogUtil {

public static String name = "app%g.log";

public static Logger obtenerLogger(String eid, String path, Level levelToLog) {
    Logger logger = Logger.getLogger(eid);
    if (levelToLog != null) {
        logger.setLevel(levelToLog);
    }

    //I create the folder if not exist
    File dirFile = new File(path);
    if (!dirFile.exists()) {
        dirFile.mkdirs();
    }

    //I remove the handlers and close after each logg call (doing this i can use the same file lof after log)
    for (Handler handler : logger.getHandlers()) {
        logger.removeHandler(handler);
        handler.close();
        handler.flush();
    }

    //I Create the FileHandler 
    FileHandler f;
    try {
        f = new FileHandler(
                path + name, //pattern
                10485760, //limit
                3, // count
                true); //append
        //f.setFormatter(new SimpleFormatter());
        f.setFormatter(new MyFormatter());
        f.setLevel(levelToLog);
    } catch (Exception ex) {
        return null;
    }

    logger.addHandler(new ConsoleHandler());
    logger.addHandler(f);

    return logger;
}

PD1: But at redeploy of the war, i call the logger class, it create a new logger, but the last one keep unclose. And that is what is bothering me (i think)

post your logger setup/configuration please – pleft Sep 19 '17 at 13:29 — pleft, Sep 19 '17 at 13:29

score 0 · Answer 1 · answered Sep 19 '17 at 14:15

The answer is here: How to create the log file for each record in a specific format using java util logging framework

I must extends a Handler and reimplement the publish method. (I was trying to implement the Logger class to close after each log call. DON'T Do That! jeje).

Thanks for your interes!

score 0 · Answer 2 · answered Sep 19 '17 at 14:29

I create a log, append a FileHandler, and i send log messages. But, like all of us know, the file handler keep the lock over the new file until i call fush() and close(), so, when i redeploy the war (or if i run it in develop, and i continously deploy the app) it create one file per deploy (ugly).

If you are programmatically setting up your logger tree and handler you should implement a custom ServletContextListener and register it with your web application. Here is an example.

Also make sure you are you are holding a strong reference to your loggers

How to avoid and controll the increment of files app.log.X in JAVA LOGGIN

2 Answers2