方法一：for循环手动拷贝

 private static int[] copyArray(int[] array) {
    
    
       int[] temp = new int[array.length];
        for (int i = 0; i < array.length; i++){
    
    
            temp[i] = array[i];
        }
        return temp;
    }

方法二：Arrays.copyOf

 public static void main(String[] args) {
    
    
        int[] array = {
    
    1,2,3,4,5,6};
        int[] ret =  Arrays.copyOf(array,array.length);
        System.out.println(Arrays.toString(ret));
    }

方法三：System.arraycopy()

public static void main(String[] args) {
    
    
        int[] array = {
    
    1,2,3,4,5,6};
        int[] ret = new int[array.length];
        System.arraycopy(array, 0, ret, 0,array.length);
        System.out.println(Arrays.toString(ret));
    }

方法四：数组名.clone()

 public static void main(String[] args) {
    
    
        int[] array = {
    
    1,2,3,4,5,6};
        int[] ret = array.clone();
        System.out.println(Arrays.toString(ret));
    }