System.arraycopy()

public static void main(String[] args) {
        /*List l = new ArrayList<String>(10);
        l.add(3, "ed");*/
        int[] src = {1,2,3,4,5,6,7};
        int[] dest = new int[7];
        int srcPos = 0;
        int destPos = 3;
        int length = 3;
        //将src数组的srcPos到srcPos+length-1处的元素移植到src数组的index等于destPos开始的索引处到destPos+length-1处
        //将src数组的0到2处的元素移植到src数组的index等于3开始的索引处
        System.arraycopy(src, srcPos, src, destPos, length);
        for(int i : src){
            System.out.println(i);
        }
        System.out.println("++++++++");
        int[] src2 = {1,2,3,4,5,6,7};
        int[] dest2 = new int[7];
        int srcPos2 = 0;
        int destPos2 = 3;
        int length2 = 3;
        System.arraycopy(src2, srcPos2, dest2, destPos2, length2);
        for(int i : dest2){
            System.out.println(i);
        }
    }