检测data空间大小的工具类

import java.util.Timer;
import java.util.TimerTask;

import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.os.StatFs;
import android.os.SystemProperties;
import android.util.Log;

public class SpaceObserver {
	
	private static SpaceObserver instance = null;
	private boolean startflag;
	private Timer timer;
	private TimerTask timerTask;
	private Handler handler;
	private long size;
	public static final int OBSERVER_DATA_LOG_SIZE = 1;
	public static final String LOG_PATH = "/data";
	public static final int OBSERVER_INTERVAL = 60 * 1000;
	public static final int DATA_LOG_MAX_SIZE = 30 * 1024 * 1024;
	
	public class ObserverTask extends TimerTask{
		
		@Override
		public void run() {
			// TODO Auto-generated method stub
			Log.e("cqupt_chen", "in the timertask");
			Message message = new Message();      
            message.what = SpaceObserver.OBSERVER_DATA_LOG_SIZE;      
            handler.sendMessage(message);  
		}
	}
	private SpaceObserver()
	{
		this.startflag = false;
		this.timer = new Timer();
		this.handler = new Handler(Looper.myLooper()){

			public void handleMessage(Message msg) {
				// TODO Auto-generated method stub
				switch (msg.what) {
				case SpaceObserver.OBSERVER_DATA_LOG_SIZE:
					
					StatFs fileStats = new StatFs(SpaceObserver.LOG_PATH);                
				    size = fileStats.getAvailableBlocks() * fileStats.getBlockSize();
				    Log.e("caupt_chen", "current data/log size " + size);
				    if (size <= SpaceObserver.DATA_LOG_MAX_SIZE) {
						SystemProperties.set(Prefs.SYSTEM_PROPERTY, Prefs.DISABLE_OFFLINE);
					}
					break;

				default:
					break;
				}
				super.handleMessage(msg);
			}
			
		};
	}
	
	
	public static synchronized SpaceObserver getInstance()
	{
		if (instance == null) {
			instance = new SpaceObserver();
			return instance;
		}
		return instance;
	}
	
	public synchronized boolean getStartflag() {
		return startflag;
	}

	private synchronized void setStartflag(boolean startflag) {
		this.startflag = startflag;
	}
	
	public synchronized void start() {
		
		if (this.startflag) {
			return;
		}
		setStartflag(true);
		timerTask = new ObserverTask();
		timer.schedule(timerTask, 0, SpaceObserver.OBSERVER_INTERVAL);
		
	}
}

SpaceObserver简单使用了一下单例模式.设置了一个标志位防止重复start线程来进行observer

import android.os.Looper;
import android.util.Log;

public class SpaceObserverThread extends Thread {

	private SpaceObserver observer;
	@Override
	public void run() {
		// TODO Auto-generated method stub
		Log.e("cqupt_chen", "start observer thread");
		Looper.prepare();
		observer = SpaceObserver.getInstance();
		observer.start();
		super.run();
		Looper.loop();
	}
	
}

加入和handler和looper做了一些消息处理