java怎么求两个数组的相同元素

如果定义两个数组
int[] a = {1,1,2,3,4,4,5,7,7};
int[] b = {2,5,4,4,4,7,7,7,7};
它们的相同元素应该是2,4,4,5,7,7,

怎么用代码求出相同元素并放到另外一个数组中

 List<String> compareList = Arrays.asList(strArr1);
List<String> baseList = Arrays.asList(strArr2);
baseList.retainAll(compareList);