Question

我创建了一个类FolderObserver，它在我的项目中观察一个文件夹以进行更改（文件创建/文件删除）。我的类正在实现Runnable接口（我使用了来自apache commons的FileAlterationObserver，FileAlterationMonitor，FileAlterationListener类）。

在我的主类中，我以FolderObserver对象作为参数启动一个线程。我想知道的是，我如何通知我的线程已发生的变化？例如，在我的文件夹中创建了一个新文件。

这是我的类FolderObserver：

public class FolderObserver implements Runnable {

private final String DIR = "server/scripts/gremlin-groovy/calculations/";

final long pollingInterval = 5000L;
private File folder;
private FileAlterationObserver observer;
private FileAlterationMonitor monitor;
private FileAlterationListener listener;



public FolderObserver()
{

    System.out.println("Creating Runnable");
    folder = new File(DIR);
    observer = new FileAlterationObserver(folder);
    monitor = new FileAlterationMonitor(pollingInterval);
}

@Override
public void run() {

    System.out.println("Thread is running");
    listener = new FileAlterationListenerAdaptor() {
            // Is triggered when a file is created in the monitored folder
            @Override
            public void onFileCreate(File file) {
                try {
                    // "file" is the reference to the newly created file

                    System.out.println("Created file : " + file.getCanonicalPath());

                } catch (IOException e) {

                }
            }

            // Is triggered when a file is deleted from the monitored folder
            @Override
            public void onFileDelete(File file) {

                try {
                    // "file" is the reference to the removed file

                    System.out.println("Removed file : " + file.getCanonicalPath());


                    //logger.log(LogLevel.DEBUG,logId,"File exists in location '{}'",bool);
                } catch (IOException e) {
                    //logger.log(LogLevel.ERROR, "Received IOException '{}' when trying to remove file", e.toString());

                }
            }
        };
        observer.addListener(listener);
        monitor.addObserver(observer);
        try {
            monitor.start();
            System.out.println("Monitor started");
            //logger.log(LogLevel.DEBUG,logId,"Monitor started");
        } catch (Exception e) {
            //logger.log(LogLevel.ERROR, "Received Exception '{}' when trying to start monitor", e.toString());
        }
}

   }

这是我从主类创建和启动线程的方法：

  FolderObserver observer = new FolderObserver();
  Thread t = new Thread(observer);
  t.start();

Answer 1

您在FolderObserver内创建了一个内部界面。

public interface MyTrueObserver(){
   public void notifySmthChanged();
}

现在，您可以通过执行

在主类中实现该类

public class MyMainClass implements MyTrueObserver()

您可以定义界面方法

public void notifySmthChanged(){
// I got called Do smth!
}

最后，您引用主要类的线程。

并在此处致电

@Override
public void onFileCreate(File file) {
               referenceObjectToMainClass.notifySmthChanged();
            }

如何通知线程的变化

1 个答案: