我试图编写一个文件监视器，它将检查文件是否添加了新行，该监视器实际上是一个线程，它将始终由randomaccessfile读取该行。

这是监视器的核心代码：

public class Monitor {
    public static Logger                                    log             = Logger.getLogger(Monitor.class);
    public static final Monitor             instance        = new Monitor();
    private static final ArrayList<Listener>    registers       = new ArrayList<Listener>();

    private Runnable                                        task            = new MonitorTask();
    private Thread                                          monitorThread   = new Thread(task);
    private boolean                                         beStart         = true;

    private static RandomAccessFile                         raf             = null;
    private File                                            monitoredFile   = null;
    private long                                            lastPos;

    public void register(File f, Listener listener) {
        this.monitoredFile = f;
        registers.add(listener);
        monitorThread.start();
    }

    public void replaceFile(File newFileToBeMonitored) {
        this.monitoredFile = newFileToBeMonitored;

        // here,how to restart the monitorThread?
    }

    private void setRandomFile() {
        if (!monitoredFile.exists()) {
            log.warn("File [" + monitoredFile.getAbsolutePath()
                    + "] not exist,will try again after 30 seconds");
            try {
                Thread.sleep(30 * 1000);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
            setRandomFile();
            return;
        }
        try {
            if (raf != null) {
                raf.close();
                lastPos = 0;
            }
            raf = new RandomAccessFile(monitoredFile, "r");
            log.info("monitor file " + monitoredFile.getAbsolutePath());
        } catch (FileNotFoundException e) {
            // The file must exist now
        } catch (IOException e) {}
    }

    private void startRead() {
        beStart = true;
        String line;
        while (beStart) {
            try {
                raf.seek(lastPos);
                while ((line = raf.readLine()) != null) {
                    fireEvent(new FileEvent(monitoredFile.getAbsolutePath(),
                            line));
                }
                lastPos = raf.getFilePointer();
            } catch (IOException e1) {}
        }
    }

    private void stopRead() {
        this.beStart = false;
    }

    private void fireEvent(FileEvent event) {
        for (Listener lis : registers) {
            lis.lineAppended(event);
        }
    }

    private class MonitorTask implements Runnable {
        @Override
        public void run() {
            stopRead();

            //why putting the resetReandomAccessFile in this thread method is that it will sleep if the file not exist.
            setRandomFile();
            startRead();
        }

    }

}

这是一些帮助类：

public interface Listener {
    void lineAppended(FileEvent event);
}


public class FileEvent {
    private String  line;
    private String  source;

    public FileEvent(String filepath, String addedLine) {
        this.line = addedLine;
        this.source = filepath;
    }
    //getter and setter

}

这是调用监视器的示例：

public class Client implements Listener {
    private static File f   = new File("D:/ab.txt");

    public static void main(String[] args) {
        Monitor.instance.register(f, new Client());
        System.out.println(" I am done in the main method");
        try {
            Thread.sleep(5000);
            Monitor.instance.replaceFile(new File("D:/new.txt"));
        } catch (InterruptedException e) {
            System.out.println(e.getMessage());
        }
    }

    @Override
    public void lineAppended(FileEvent event) {
        String line = event.getLine();
        if (line.length() <= 0)
            return;
        System.err.println("found in listener:" + line + ":" + line.length());
    }
}

现在，我的问题是，如果我仅调用以下代码，代码就可以很好地工作：

Monitor.instance.register(file,listener);

这将监视文件的行追加，并通知侦听器。

但是，当我致电：

Monitor.instance.replaceFile(anotherfile);

这意味着我想监视另一个文件而不是之前。

因此，在Monitor中，我必须重新启动线程，该怎么做？

我已经尝试过：

monitorThread.interruppt();

它不会扭曲。

任何人都可以为我修复它或告诉我该怎么做？

谢谢。

在我询问之前，我已经搜索了“重新启动Java线程”，因此我知道一个无法重新启动死线程，但是我的线程不返回，因此我认为可以重新启动它。