bt_click.setOnClickListener(new OnClickListener() {
      @Override
      public void onClick(View v) {
        if(startTime!=0){
          long endTime = System.currentTimeMillis();
          if(endTime-startTime<500){
            Toast.makeText(getApplicationContext(), "点击了两下", 0).show();
          }
        }
        startTime = System.currentTimeMillis();
      }
    });

    //静态初始化两个长度不同的数组
    int src[] = {1,2,3,4,5,6};
    int dest[] = {10,9,8,7,6,5,4,3,2,1};
    //将数组src的4个元素copy到数组dest中
    System.arraycopy(src,1,dest,2,4);

    //输出数组dest
    for(int i=0;i<10;i++)
    {
      System.out.println(dest[i]);
    }

private long[] mHits = new long[3];
    bt_many_click.setOnClickListener(new OnClickListener() {
      @Override
      public void onClick(View v) {
        System.arraycopy(mHits, 1, mHits, 0, mHits.length-1);
        mHits[mHits.length-1] = SystemClock.uptimeMillis();
        if(mHits[mHits.length-1]-mHits[0]<500){
          //响应了一个三击事件
          Toast.makeText(getApplicationContext(), "点击了三下!!!!", 0).show();
        }
      }
    });