使用Tailer和WatchService

时间:2015-07-22 16:26:10

标签: java watchservice apache-tailer

我使用此代码同时使用Tailer和WatchService:

AgentTailerListener listener = new AgentTailerListener();
Tailer tailer;

WatchService watcher = FileSystems.getDefault().newWatchService();
while (true) {
    WatchKey watchKey;
    watchKey = Paths.get("/tmp").register(watcher, ENTRY_CREATE);
    watchKey = watcher.take();

    for (WatchEvent<?> event : watchKey.pollEvents()) {
        if (event.kind() == StandardWatchEventKinds.ENTRY_CREATE) {
            tailSource = event.context().toString();
            System.out.println(tailSource);
            File file = new File("/tmp/" + tailSource);
            String end = "log";

            if (file.getName().endsWith(end)) {
                tailer = TailerFactory.createTailer(file, listener);
                (new Thread(tailer)).start();
            }

        }
    }

    watchKey.reset();
    transport.close();
}

但问题是:我想只检查一个带有tailer的文件(比如停止线程,但是我无法阻止特定于文件的线程),当我通过echo命令写入文件时,并非我写的所有信件都出现了。

当我连续几次用echo写相同的文字时,所有的字母都被写出来。

我看到了这个主题,How to tail -f the latest log file with a given pattern,但我不知道我是否可以将它用于我的问题(我不知道尾巴和尾标之间的区别)。

1 个答案:

答案 0 :(得分:0)

最后,我认为这更好:

AgentTailerListener listener = new AgentTailerListener();
Tailer tailer;
String tailSource;
Thread thread;

WatchService watcher = FileSystems.getDefault().newWatchService();

WatchKey watchKey;
watchKey = Paths.get("/tmp").register(watcher, ENTRY_CREATE);

List<Thread> threadList = new ArrayList<Thread>();
while (true) {
    watchKey = watcher.take();
    for (WatchEvent<?> event : watchKey.pollEvents()) {
    if (event.kind() == StandardWatchEventKinds.ENTRY_CREATE) {

        tailSource = event.context().toString();
        System.out.println(tailSource);
        File file = new File("/tmp/" + tailSource);
        String end = "log";
        if (file.getName().endsWith(end)) {
            tailer= TailerFactory.createTailer(file, listener);
            if(threadList.isEmpty()){}
            else{
                Thread.sleep(1000);
                threadList.get(0).stop();
                threadList.clear();}
            System.out.println(threadList.size());
            threadList.add(thread = new Thread(tailer));
            threadList.get(0).start();
            }
    }
}
watchKey.reset();

} 

但它创建了很多线程,我想我必须使用修复线程池。