android.os.FileObserver#MOVED_FROM源码实例Demo

private void restart() {
    //noinspection ResultOfMethodCallIgnored
    dataDir.mkdirs();

    fileObserver = new FileObserver(dataDir.getAbsolutePath(), FileObserver.CREATE | FileObserver.DELETE_SELF | FileObserver.MOVED_FROM | FileObserver.MOVED_TO) {
        @Override
        public void onEvent(int event, String file) {
            Log.d(Constants.TAG, "Control Directory Changed " + file);

            if ((event & FileObserver.DELETE_SELF) != 0) {
                restart();
            } else {
                file = file.toUpperCase();

                switch (file) {
                    case "STOP":
                    case "START":
                    case "RESTART":
                        callback.onUserControl(file);
                }
            }
        }
    };

    fileObserver.startWatching();
}
 

@Override
public void onEvent(int event, String file) {
    MLog.d(TAG, "qq -> " + event);
    MLog.d(TAG, "qq2 -> " + file);

    if ((FileObserver.CREATE & event) != 0) {
        MLog.d(TAG, "File created [" + PhonkSettings.getBaseDir() + file + "]");
        EventBus.getDefault().postSticky(new Events.ProjectEvent(Events.PROJECT_REFRESH_LIST, null));
    } else if ((FileObserver.DELETE & event) != 0) {
        MLog.d(TAG, "File deleted [" + PhonkSettings.getBaseDir() + file + "]");
        EventBus.getDefault().postSticky(new Events.ProjectEvent(Events.PROJECT_REFRESH_LIST, null));
    } else if ((FileObserver.MOVED_FROM & event) != 0) {
        MLog.d(TAG, "File moved from [" + PhonkSettings.getBaseDir() + file + "]");
        EventBus.getDefault().postSticky(new Events.ProjectEvent(Events.PROJECT_REFRESH_LIST, null));
    } else if ((FileObserver.MOVED_TO & event) != 0) {
        MLog.d(TAG, "File moved to [" + PhonkSettings.getBaseDir() + file + "]");
        EventBus.getDefault().postSticky(new Events.ProjectEvent(Events.PROJECT_REFRESH_LIST, null));
    }
}
 

@Override
public void onEvent(int event, String path) {
    // this will automatically update the directory when an action like this
    // will be performed
    switch (event & FileObserver.ALL_EVENTS) {
        case FileObserver.CREATE:
        case FileObserver.CLOSE_WRITE:
        case FileObserver.MOVE_SELF:
        case FileObserver.MOVED_TO:
        case FileObserver.MOVED_FROM:
        case FileObserver.ATTRIB:
        case FileObserver.DELETE:
        case FileObserver.DELETE_SELF:
            sHandler.removeCallbacks(mLastRunnable);
            sHandler.post(mLastRunnable =
                    new NavigateRunnable((AbstractBrowserActivity) getActivity(), path));
            break;
    }
}
 

private static List<String> getModulesList(final int user) {
    final int index = modulesList.indexOfKey(user);
    if (index >= 0) {
        return modulesList.valueAt(index);
    }

    final String filename = String.format("/data/user_de/%s/%s/conf/enabled_modules.list", user, APPLICATION_ID);
    final FileObserver observer = new FileObserver(filename) {
        @Override
        public void onEvent(int event, @Nullable String path) {
            switch (event) {
                case FileObserver.MODIFY:
                    modulesList.put(user, readModulesList(filename));
                    break;
                case FileObserver.MOVED_FROM:
                case FileObserver.MOVED_TO:
                case FileObserver.MOVE_SELF:
                case FileObserver.DELETE:
                case FileObserver.DELETE_SELF:
                    modulesList.remove(user);
                    modulesListObservers.remove(user);
                    break;
            }
        }
    };
    modulesListObservers.put(user, observer);
    final List<String> list = readModulesList(filename);
    modulesList.put(user, list);
    observer.startWatching();
    return list;
}
 

public static String toString(final int event) {
    switch (event) {
        case FileObserver.ACCESS:
            return "ACCESS";
        case FileObserver.MODIFY:
            return "MODIFY";
        case FileObserver.ATTRIB:
            return "ATTRIB";
        case FileObserver.CLOSE_WRITE:
            return "CLOSE_WRITE";
        case FileObserver.CLOSE_NOWRITE:
            return "CLOSE_NOWRITE";
        case FileObserver.OPEN:
            return "OPEN";
        case FileObserver.MOVED_FROM:
            return "MOVED_FROM";
        case FileObserver.MOVED_TO:
            return "MOVED_TO";
        case FileObserver.CREATE:
            return "CREATE";
        case FileObserver.DELETE:
            return "DELETE";
        case FileObserver.DELETE_SELF:
            return "DELETE_SELF";
        case FileObserver.MOVE_SELF:
            return "MOVE_SELF";
        default:
            return "0x" + Integer.toHexString(event);
    }
}
 

@Override
public void onEvent(int event, final String path) {
	if (path == null) {
		return;
	}
	
	switch (event & FileObserver.ALL_EVENTS) {
	case FileObserver.CLOSE_WRITE:
		// Download complete, or paused when wifi is disconnected. Possibly reported more than once in a row.
		// Useful for noticing when a download has been paused. For completions, register a receiver for 
		// DownloadManager.ACTION_DOWNLOAD_COMPLETE.
		break;
	case FileObserver.OPEN:
		// Called for both read and write modes.
		// Useful for noticing a download has been started or resumed.
		break;
	case FileObserver.DELETE:
	case FileObserver.MOVED_FROM:
		// This video is lost never to return. Remove it.
		handler.post(new Runnable() {
			@Override
			public void run() {
				DatabaseHelper helper = dataService.getHelper();
				helper.removeDownloadFromDownloadManager(helper.getVideoForFilename(path));
			}
		});
		break;
	case FileObserver.MODIFY:
		// Called very frequently while a download is ongoing (~1 per ms).
		// This could be used to trigger a progress update, but that should probably be done less often than this.
		shouldPoll = true;
		break;
	}
}