无法获取 spring 启动 hibernate rest Z8A5DA52ED126447D359E70C05721 一个到多个关系

Question

I have modelled a car park with building and floor models. There is a one to many relationship between building and floor. I have built a rest controllers to retrieve the data. I am attempting to retrive the data via a simple get request to api/v1/parkingbuildings/1/ . The issue is that when retrieving a building i do not see a list of floors as per my relation mapping. Any insight into any mistakes i may be making would be appreciated. Below is the json that gets returned;

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

I am expecting to see a collection of floors in the payload and i cannot fathom why, ive written other similar simpler solutions that do the same without issue, ive compared my prior solutions and see little difference that matters in my approach.

Here is my building model

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;
    }


}

And here is my floor model

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;
    }
}

Here is my building controller

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

Not sure how you are retrieving the floors. OneToMany is by default lazy and would not load unless asked.

In your repository, try:

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

Answer 2

The issue was with the @Jsonignore annotations i used. I had to be more specific with the @Jsonignoreproperty annotation to target which properties i did not want to serialise.