Java冒泡

public sortNode[] sort() {
        boolean flag = true;
        for (int i = 0, len = arr.length-1; i < len; i++) {
            for (int j = 0; j < len - i - 1; j++) {
                if (((sortNode)arr[j]).getIndex() > ((sortNode)arr[j + 1]).getIndex()) {
                    sortNode temp = (sortNode)arr[j + 1];
                    arr[j + 1] = arr[j];
                    arr[j] = (T) temp;
                    flag = false;
                }
            }
            if(flag)break;
        }
        return (sortNode[]) arr;
    }