使用Handler和Runnable做一些轮询请求

实现方法：

private Handler mHandler = new Handler();
    private Runnable runnable;

//第一次调用开始循环

private void getPolling() {
		runnable = new Runnable() {
            @Override
            public void run() {
                mHandler.postDelayed(this, 5 * 1000);
                //需要做轮询的方法
            }
        };
        mHandler.postDelayed(runnable, 5 * 1000);
    }

//记得销毁

@Override
    public void onDestroy() {
        super.onDestroy();
        mHandler.removeCallbacks(runnable);
    }