Question

我需要在更新swing组件中的值时更改文件后触发事件。这些值存储在文件中。现在我需要检索更新的值。

Answer 1

查看适用于Java的官方io通知API指南：http://docs.oracle.com/javase/tutorial/essential/io/notification.html

类似的东西：

public class myFileWatcherBean implements ActionListener {

    private Component someComponent;

    public myFileWatcherBean() {
        someComponent.addActionListener(this);
    }

    public void watchForChanges() {
        WatchService watcher = FileSystems.getDefault().newWatchService();
        Path dir = ...;

        try {
            WatchKey key = dir.register(watcher,
                       ENTRY_CREATE,
                       ENTRY_DELETE,
                       ENTRY_MODIFY);
            key = watcher.take();
            for (WatchEvent<?> event: key.pollEvents()) {
                  actionPerformed(new ActionEvent(this, ActionEvent.ACTION_PERFORMED, null) {
      //Nothing need go here, the actionPerformed method (with the
      //above arguments) will trigger the respective listener
});
            }
        } catch (IOException x) {
            System.err.println(x);
        }

    }
}

PS：代码需要一些修改，但我认为你会得到这个想法。

参考文献： Can I watch for single file change with WatchService (not the whole directory)? How do I manually invoke an Action in swing? http://docs.oracle.com/javase/tutorial/essential/io/notification.html#try http://docs.oracle.com/javase/tutorial/uiswing/events/actionlistener.html

如何在java swing应用程序中编写ActionListener事件以进行文件更改？

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