每天创建新文件的Java.util.logger

Question

我正在使用java.util.logging框架在我的JSF应用程序中实现日志记录。我已经成功地完成了这个实现，但是我有一个新的需求要轮换日志并为每一天创建一个新的日志文件。

我无法找出如何实现这一点。如果有任何关于实现的提示，将不胜感激。谢谢。

这是我配置日志记录器的方式:

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

- Sirish V

Answer 1

由于您正在使用代码设置FileHandler，因此可以使用“％g”关闭和重新创建FileHandler的{{link1：添加代码}}。

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);
}

如果您希望它自动工作，只需为FileHandler创建一个代理处理程序来处理每天关闭和重新创建文件即可。

- jmehrens

Answer 2

Java.util.logging不支持按日轮换，可以参考这个错误报告：http://bugs.java.com/bugdatabase/view_bug.do?bug_id=6350749 另外，您可以使用logback、log4j或log4j2和slf4j来隧道JUL（请参见http://www.slf4j.org/legacy.html#jul-to-slf4j）。 所有提到的框架都支持基于日期的文件轮换。

希望对您有所帮助，Mark

- mp911de

Answer 3

创建一个任务，使用ScheduledThreadPoolExecutor在每天午夜执行，然后在任务中处理并关闭当前的FileHandler，并创建一个新的FileHandler来更新文件名。类似如下代码可行：

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());
    }  
}

}

- Rok T.