java for循环遍历问题

userList集合里面有两个userid，怎么给他遍历出来？代码应该怎么写？

代码如下：

public static void main(String[] args) {
        List<Long> userList = new ArrayList<>();
        userList.add(1L);
        userList.add(2L);
        for (Long aLong : userList) {
            System.out.println("userId=" + aLong);
        }
    }

执行结果：

userId=1
userId=2

public static void main(String[] args) {
        List<String> list = new ArrayList<String>();

        list.add("string1");

        list.add("string1");

        list.add("string1");

        list.add("string1");

        list.add("string3");

        list.add("string2");

        list.add("string2");

        HashMap<String, Integer> hashMap = new HashMap<String, Integer>();

        for (String string : list) {

            if (hashMap.get(string) != null) {

                Integer value = hashMap.get(string);

                hashMap.put(string, value+1);

                System.out.println("the element:"+string+" is repeat");

            } else {

                hashMap.put(string, 1);

            }

        }

    }