简单防止多次点击，例如防止弹出两个相同popwidow

1、调用封装方法

if (ClickFilter.isFastClick()) {
    return;
}

2、具体的封装方法

public class ClickFilter {
    private static long lastClickTime;
    public synchronized static boolean isFastClick() {
        long time = System.currentTimeMillis();
        if ( time - lastClickTime < 500) {
            return true;
        }
        lastClickTime = time;
        return false;
    }
}