给定一个部门，输出当前部门的所有父部门及其自己。如下图：

分析：

1：如果直接就是一级部门,直接返回；

2：如果不是一级部门,就递归查询。同样需要注意去重

代码：

public class AllParentDepartment {

    public static void main(String[] args) {
        AllParentDepartment allDepartment = new AllParentDepartment();
        List<Department> list = allDepartment.initDepartment();
        Department d1 = new Department();
        d1.setParentId(7);
        d1.setId(10);
        d1.setName("高级Java");
        List<Department> myParentList = allDepartment.getMyAllParentDepartmentList(d1, list);
        myParentList.forEach(System.out::println);
    }

    private List<Department> getMyAllParentDepartmentList(Department d1, List<Department> list) {
        List<Department> result = new ArrayList<>();
        Integer parentId = d1.getParentId();
        result.add(d1);
        if (0 == parentId) {
            return result;
        }
        doMyAllParentDepartmentList(d1, list, result);
        return result;
    }

    private void doMyAllParentDepartmentList(Department d1, List<Department> list, List<Department> result) {
        Integer parentId = d1.getParentId();
        if (0 == parentId && !result.contains(d1)) {
            result.add(d1);
            return;
        }
        List<Department> parent0 = list.stream().filter(dep -> dep.getId().equals(parentId)).collect(Collectors.toList());
        if (parent0.isEmpty()) {
            return;
        }
        Department department = parent0.get(0);
        result.add(department);
        doMyAllParentDepartmentList(department, list, result);

    }


    private List<Department> initDepartment() {
        List<Department> list = new ArrayList<>();
        Department d1 = new Department();
        d1.setParentId(0);
        d1.setId(1);
        d1.setName("技术部");

        Department d2 = new Department();
        d2.setParentId(0);
        d2.setId(2);
        d2.setName("人事部");


        Department d3 = new Department();
        d3.setParentId(0);
        d3.setId(3);
        d3.setName("财务部");

        Department d4 = new Department();
        d4.setParentId(1);
        d4.setId(4);
        d4.setName("大前端");

        Department d5 = new Department();
        d5.setParentId(1);
        d5.setId(5);
        d5.setName("后端");


        Department d6 = new Department();
        d6.setParentId(1);
        d6.setId(6);
        d6.setName("产品");


        Department d7 = new Department();
        d7.setParentId(5);
        d7.setId(7);
        d7.setName("Java");

        Department d8 = new Department();
        d8.setParentId(5);
        d8.setId(8);
        d8.setName("PHP");

        Department d9 = new Department();
        d9.setParentId(5);
        d9.setId(9);
        d9.setName("大数据");

        Department d10 = new Department();
        d10.setParentId(7);
        d10.setId(10);
        d10.setName("高级Java");

        Department d11 = new Department();
        d11.setParentId(9);
        d11.setId(11);
        d11.setName("大屏幕");

        Department d12 = new Department();
        d12.setParentId(4);
        d12.setId(12);
        d12.setName("IOS");

        Department d13 = new Department();
        d13.setParentId(2);
        d13.setId(13);
        d13.setName("HRBP");

        list.add(d1);
        list.add(d2);
        list.add(d3);
        list.add(d4);
        list.add(d5);
        list.add(d6);
        list.add(d7);
        list.add(d8);
        list.add(d9);
        list.add(d10);
        list.add(d11);
        list.add(d12);
        list.add(d13);
        return list;
    }
}


@Data
class Department {
    private Integer parentId;

    private Integer id;

    private String name;

}

运行结果：