List集合保存对象，存储的是对象的地址

下面是先创建对象后，不断改变对象的名称保存到集合里

public static void test() {
        List<Employee> nameList = new ArrayList<>();
        Employee employee = new Employee();
        for (int i = 0; i < 3; i++) {
            employee.setName("张"+i);
            nameList.add(employee);
        }
        nameList.forEach(System.out::println);
    }

结果如下，全是相同的姓名

List集合保存对象，存储的是对象的地址

public static void test2() {
        List<Employee> nameList = new ArrayList<>();
        for (int i = 0; i < 3; i++) {
            Employee employee = new Employee();
            employee.setName("张"+i);
            nameList.add(employee);
        }
    }