无法让spring boot hibernate rest api返回一对多关系

Question

我用建筑模型和地板模型为停车场建模。建筑物和楼层之间存在一对多的关系。我已经建立了一个休息控制器来检索数据。我正在尝试通过对api/v1/parkingbuildings/1/ 的简单获取请求来检索数据。问题是，在检索建筑物时，根据我的关系映射，我没有看到楼层列表。对我可能犯的任何错误的任何见解将不胜感激。下面是返回的json；

{"building_id":1,"building_name":"Labadiestad","postcode":"SA78BQ","max_floors":14,"owner_name":"Schaefer, Gutmann and Braun"}

我希望在有效载荷中看到一系列楼层，但我无法理解为什么，我编写了其他类似的更简单的解决方案，它们可以毫无问题地做同样的事情，我比较了我以前的解决方案，发现我的方法没有什么不同。

这是我的建筑模型

package com.admiral.reslink.models;

import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.annotation.JsonIgnoreProperties;

import javax.persistence.*;
import java.util.ArrayList;
import java.util.List;

@Entity(name = "parking_buildings")
@JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
public class ParkingBuilding {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private long building_id;

    private String building_name;
    private String postcode;
    private int max_floors;
    private String owner_name;

    // ToDo sort the relationships

    @OneToMany(mappedBy = "parkingBuilding")
    @JsonIgnore
    private List<ParkingFloor> parkingFloors;

    public ParkingBuilding() {
    }

    public long getBuilding_id() {
        return building_id;
    }

    public void setBuilding_id(long building_id) {
        this.building_id = building_id;
    }

    public String getBuilding_name() {
        return building_name;
    }

    public void setBuilding_name(String building_name) {
        this.building_name = building_name;
    }

    public String getPostcode() {
        return postcode;
    }

    public void setPostcode(String postcode) {
        this.postcode = postcode;
    }

    public int getMax_floors() {
        return max_floors;
    }

    public void setMax_floors(int max_floors) {
        this.max_floors = max_floors;
    }

    public String getOwner_name() {
        return owner_name;
    }

    public void setOwner_name(String owner_name) {
        this.owner_name = owner_name;
    }

    public List<ParkingFloor> getParkingFloors() {
        return parkingFloors;
    }

    public void setParkingFloors(List<ParkingFloor> parkingFloors) {
        this.parkingFloors = parkingFloors;
    }


}

这是我的地板模型

package com.admiral.reslink.models;

import com.fasterxml.jackson.annotation.JsonIgnore;
import com.fasterxml.jackson.annotation.JsonIgnoreProperties;

import javax.persistence.*;
import java.util.List;

@Entity
@Table(name = "parking_floors")
@JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})

public class ParkingFloor {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private long floor_id;

    private int floor_number;
    private int max_height_inches;
    private boolean is_covered;
    private boolean is_disabled_access;

    // ToDo sort the relationships
    @ManyToOne
    @JoinColumn(name="building_id", nullable=false)
    private ParkingBuilding parkingBuilding;

    @OneToMany(mappedBy = "parkingFloor")
    @JsonIgnore
    private List<ParkingSpace> parkingSpace;

    public ParkingFloor() {
    }

    public long getFloor_id() {
        return floor_id;
    }

    public void setFloor_id(long floor_id) {
        this.floor_id = floor_id;
    }

    public int getFloor_number() {
        return floor_number;
    }

    public void setFloor_number(int floor_number) {
        this.floor_number = floor_number;
    }

    public int getMax_height_inches() {
        return max_height_inches;
    }

    public void setMax_height_inches(int max_height_inches) {
        this.max_height_inches = max_height_inches;
    }

    public boolean isIs_covered() {
        return is_covered;
    }

    public void setIs_covered(boolean is_covered) {
        this.is_covered = is_covered;
    }

    public boolean isIs_disabled_access() {
        return is_disabled_access;
    }

    public void setIs_disabled_access(boolean is_disabled_access) {
        this.is_disabled_access = is_disabled_access;
    }

    public ParkingBuilding getParkingBuilding() {
        return parkingBuilding;
    }

    public void setParkingBuilding(ParkingBuilding parkingBuilding) {
        this.parkingBuilding = parkingBuilding;
    }

    public List<ParkingSpace> getParkingSpace() {
        return parkingSpace;
    }

    public void setParkingSpace(List<ParkingSpace> parkingSpace) {
        this.parkingSpace = parkingSpace;
    }
}

这是我的建筑控制器

package com.admiral.reslink.controllers;

import com.admiral.reslink.models.ParkingBuilding;
import com.admiral.reslink.models.ParkingFloor;
import com.admiral.reslink.repositories.ParkingBuildingRepository;
import com.admiral.reslink.repositories.ParkingFloorRepository;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;

@RestController
@RequestMapping("/api/v1/parkingbuildings")
public class ParkingBuildingController {

    @Autowired
    private ParkingBuildingRepository parkingBuildingRepository;

    @GetMapping
    public List<ParkingBuilding> list() {return parkingBuildingRepository.findAll();}

    @GetMapping
    @RequestMapping("{id}")
    public ParkingBuilding get(@PathVariable Long id) {return  parkingBuildingRepository.getById(id);}

    @PostMapping
    public ParkingBuilding create(@RequestBody final ParkingBuilding parkingBuilding) {
        return parkingBuildingRepository.saveAndFlush(parkingBuilding);
    }

    @RequestMapping(value="{id}", method = RequestMethod.DELETE)
    public void delete(@PathVariable Long id) {
        parkingBuildingRepository.deleteById(id);
    }

    @RequestMapping(value="{id}", method = RequestMethod.PUT)
    public ParkingBuilding update(@PathVariable Long id, @RequestBody ParkingBuilding parkingBuilding) {
        ParkingBuilding existingParkingBuilding = parkingBuildingRepository.getById(id);
        BeanUtils.copyProperties(parkingBuilding, existingParkingBuilding, "building_id");
        return parkingBuildingRepository.saveAndFlush(existingParkingBuilding);
    }
}

Answer 1

不确定您是如何检索地板的。 OneToMany 默认为lazy，除非被询问，否则不会加载。

在您的存储库中，尝试：

@EntityGraph(attributePaths = "parkingFloors")
ParkingBuilding findById(long id);