NClick.java

long[] mClicks = new long[n];

view.setOnClickListener(new OnClickListener() {
			
 @Override
 public void onClick(View v) {
    System.arraycopy(mClicks, 1, mClicks, 0, mClicks.length - 1);
    mClicks[mClicks.length - 1] = SystemClock.uptimeMillis();
     if(mClicks[0] >= (SystemClock.uptimeMillis() - 500)){
       doSomething();
  }
}