Java帮助ArrayList的ArrayList不是唯一的

Question

我有一小部分只是半功能的代码。有人可以向我解释为什么我的ArrayList＆gt; ALL_PIXELS为每个位置保持相同的值？

//为什么这不会使每行的ALL_PIXELS唯一.............

    for (int i = 0; i < FRAME_HEIGHT; i++) {

        HashMap<String, Double> t = boundsHistory.get(zoomNum);
        PI task = new PI(i, t);
        //this is the problem. some where 
        ArrayList<Integer> temp = new ArrayList<Integer>();
        temp = task.execute();
        //System.out.println(temp);
        ALL_PIXELS.add(temp);
        //System.out.println(ALL_PIXELS.get(i));     //still unique here....WHYYYYYYY
        //System.out.println(temp);     //this shows that temp is a unique array each row

    }// end for loop    



    //why is all pixels seting the same vales to all of its sub arrays
    //System.out.println(ALL_PIXELS.get(3));
    //System.out.println(ALL_PIXELS.get(300));

当我在for循环后打印出来时，如何确保ALL_PIXELS数组列表保持唯一，那么任何建议都会很好。