class Employee {
private String name;
private List<Employee> members;
}
List<Employee> emps = Arrays.asList(new Employee("A", Arrays.asList(
new Employee("B", null),
new Employee("C", null)
)))
代码用于将
List
展开:List<Employee> total =
emps.stream()
.flatMap(emp -> emp.members.stream())
.collect(Collectors.toList());
总的List
应该有3个元素,但它只有2个。