向Controller传入数组参数，查询多条数据

请求地址：localhost:8989/SmartPush/Users

请求参数：{“department_id”:[41,42]}

1.先定义实体类

@Data
public class PushUser {
    private Integer id;
    private String name;
    private Integer department_id;
    private String phone;
    private Integer height;
    private Integer weight;
    @JsonIgnore //此注解用于隐藏该字段，不向前端返回
    private Date birthday;
    private Integer age;
    private Integer sex;
}

2.再定义一个实体类，用于存放传入的数组型的id

@Data
public class RequestDepartmentID {
    private  ArrayList<Integer> department_id;
}

3.Controller

@Slf4j
@RestController
@RequestMapping("/SmartPush")
public class SmartPushController {
    @Autowired
    private SmartPushService smartPushService;
    @PostMapping("/Users")
    public ResponseData SmartPushUsers(@RequestBody RequestDepartmentID ReqID) {
        ResponseData responseData = new ResponseData();
        ArrayList<Integer> deptid = ReqID.getDepartment_id();
        Collections.sort(deptid);
        if (deptid.size()<=0) {
            responseData.setCode(-1);
            responseData.setMessage("该部门信息有误");
            responseData.setData(null);
            return responseData;
        } else {
            responseData.setData(smartPushService.getUsersByDepartmentid(deptid));
            responseData.setCode(200);
            return responseData;
        }
    }
}

4.Service

@Service
public class SmartPushService {
    @Autowired
    private TaUserDao taUserDao;
    public List<PushUser> getUsersByDepartmentid(ArrayList<Integer> department_id){
        List<PushUser> list = new ArrayList<>();
        if (department_id != null) {
            List<PushUser> users = taUserDao.getUsersByDepartment_id(department_id);
            //lamda表达式，将users集合按人员身高从高到低排序，关键方法：.reversed
            list = users.stream()
                        .sorted(Comparator.comparing(PushUser::getHeight)
                        .reversed()).collect(Collectors.toList());
        }
        return list;
    }
}

5.Dao

@Mapper
public interface TaUserDao {
    List<PushUser> getUsersByDepartment_id(ArrayList<Integer> department_id);
}

6.XML

<!--关键方法：<foreach> 里面的东西不用改，直接复用-->
<select id="getUsersByDepartment_id" resultType="com.jfsystem.manage.dwpc.model.PushUser">
        select id,name,height,department_id,weight,TIMESTAMPDIFF(YEAR, birthday, CURDATE()) as age,phone,sex FROM ta_user where department_id in
        <foreach collection="list" open="(" close=")" separator="," item="item">
            #{item}
        </foreach>
        ORDER BY RAND() LIMIT 6;
</select>

7.返回的数据

{
    "code": 0,
    "message": null,
    "data": [
        {
            "id": 48,
            "name": "李伟",
            "department_id": 42,
            "phone": "18747205204",
            "height": 175,
            "weight": 80,
            "age": 30,
            "sex": 1
        },
        {
            "id": 99,
            "name": "常威",
            "department_id": 41,
            "phone": "13039586119",
            "height": 173,
            "weight": 146,
            "age": 25,
            "sex": 1
        },
        {
            "id": 87,
            "name": "曹操",
            "department_id": 42,
            "phone": "18648467050",
            "height": 171,
            "weight": 74,
            "age": 23,
            "sex": 1
        },
        {
            "id": 69,
            "name": "王凯",
            "department_id": 42,
            "phone": "17604875674",
            "height": 169,
            "weight": 140,
            "age": 24,
            "sex": 1
        },
        {
            "id": 133,
            "name": "刘磊",
            "department_id": 41,
            "phone": "17604854980",
            "height": 166,
            "weight": 72,
            "age": 20,
            "sex": 1
        },
        {
            "id": 123,
            "name": "张讯",
            "department_id": 42,
            "phone": "18586185119",
            "height": 165,
            "weight": 66,
            "age": 24,
            "sex": 1
        }
    ]
}