[FIXED] how to save bidrectional entity with dto

Issue

I have two spring boot entities MeetingSetting and MeetingTime, MeetingSetting can have multiple MeetingTimes. I am trying to save these to at the same time with the DTO structure, so I can avoid the circular reference problem when I am getting MeetingTimes. Saving partially works. MeetingSettings has a property called meetingName which is a foreign key in meetingTimes. Everything except meetingName is saved which is for some reason null, but I can not find the reason, could someone maybe look at my code and tell me what I am missing?

MeetingSetting Entity:

@Entity
@Table(name = "meeting_settings")
@Setter
@Getter
public class MeetingsSetting implements Serializable {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @Column(name = "meeting_name", unique = true)
    private String meetingName;

    @Column(name = "meeting_url")
    private String meetingUrl;

    @Column(name = "meeting_pw")
    private String meetingPw;

    @OneToMany(mappedBy = "meetingName", cascade = CascadeType.ALL, fetch = FetchType.LAZY)
    private Set<MeetingTime> meetingTime = new HashSet<>();
}

MeetingSettingDTO:

@Getter
@Setter
public class MeetingSettingDTO {


    private Long id;


    @NotNull
    private String meetingName;

    @NotNull
    private String meetingUrl;

    @NotNull
    private String meetingPw;

    private Set<MeetingTime> meetingTime;
}

MeetingTime Entity:

@Entity
@Table(name = "meeting_times")
@Getter
@Setter
public class MeetingTime implements Serializable {

    @JsonIgnore
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Long id;

    @Column(name = "meeting_date")
    private String date;

    @Column(name = "start_time")
    private String startTime;

    @Column(name = "end_time")
    private String endTime;

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "meeting_name" , referencedColumnName = "meeting_name")
    private MeetingsSetting meetingName;
}

MeetingTimeDTO:

@Getter
@Setter
public class MeetingTimeDTO {


    private Long id;

    @NotNull
    private String date;

    @NotNull
    private String startTime;
    @NotNull
    private String endTime;

    private Set<MeetingSettingDTO> meetingSettings;

}

And finally the controller where I am saving everything (Just save method):

@PostMapping("/")
    public void saveMeeting(@RequestBody MeetingSettingDTO meetingSettingDTO){
       MeetingsSetting meetingsSetting = new MeetingsSetting();
       meetingsSetting.setMeetingName(meetingSettingDTO.getMeetingName());
       meetingsSetting.setMeetingPw(meetingSettingDTO.getMeetingPw());
       meetingsSetting.setMeetingUrl(meetingSettingDTO.getMeetingUrl());
        Set<MeetingTime> meetingTimeSet = meetingSettingDTO.getMeetingTime();
        meetingsSetting.setMeetingTime(meetingTimeSet);
        meetingSettingService.saveMeeting(meetingsSetting);

    }

My service is just implementing a jpaRepository which takes MeetingSetting as parameter

Solution

In your MeetingTime entity class you have a parent:

    @ManyToOne(fetch = FetchType.LAZY)
    @JoinColumn(name = "meeting_name" , referencedColumnName = "meeting_name")
    private MeetingsSetting meetingName;

You have to set it explicitly for each MeetingTime, so add this:

Set<MeetingTime> meetingTimeSet = meetingSettingDTO.getMeetingTime();
meetingTimeSet.forEach(m -> m.meetingName(meetingsSetting));

Answered By - George Lvov