如何让getMapping显示数据spring开机

Question

I have a vue application where I am making an axios.get request to my backend. I just want the data which is send from the backend to write to the console but it does not work. There is no value returned. I tried to do a request through postman the response is 200 but there is no json object shown. No errors are shown either I could not find any errors because of that.

Vue axios:

getMeetingTimes(){
      axios.get("http://localhost:8081/api/meetingTime/")
      .then(function(response){
        console.log(response.headers)
      })
}

Spring entities:

MeetingSetting:

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

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

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

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

    @Column(name = "meeting_name")
    private String meeting_name;

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

    @ManyToOne
    @JoinColumn(name = "meeting_name" ,insertable = false, updatable = false, referencedColumnName = "meeting_name")
    private MeetingsSetting meetingName;
}

Service:

@Service
public class MeetingTimeService {

    @Autowired
    MeetingTimeRepository meetingTimeRepository;

    public List<MeetingTime> findAllMeetingTimes(){
    System.out.println("HALLOOO "+meetingTimeRepository.findAll());
        return meetingTimeRepository.findAll();
    }
}

this is the log I am getting from intellj:

Hibernate: select meetingtim0_.id as id1_1_, meetingtim0_.meeting_date as meeting_2_1_, meetingtim0_.end_time as end_time3_1_, meetingtim0_.meeting_name as meeting_4_1_, meetingtim0_.start_time as start_ti5_1_ from meeting_times meetingtim0_
Hibernate: select meetingsse0_.id as id1_0_0_, meetingsse0_.meeting_name as meeting_2_0_0_, meetingsse0_.meeting_pw as meeting_3_0_0_, meetingsse0_.meeting_url as meeting_4_0_0_ from meeting_settings meetingsse0_ where meetingsse0_.meeting_name=?
Hibernate: select meetingsse0_.id as id1_0_0_, meetingsse0_.meeting_name as meeting_2_0_0_, meetingsse0_.meeting_pw as meeting_3_0_0_, meetingsse0_.meeting_url as meeting_4_0_0_ from meeting_settings meetingsse0_ where meetingsse0_.meeting_name=?
HALLOOO [com.cbc.coorporateblinddateservice.entities.dates.MeetingTime@4b385665, com.cbc.coorporateblinddateservice.entities.dates.MeetingTime@5afe0ab6, com.cbc.coorporateblinddateservice.entities.dates.MeetingTime@7a395a1b, com.cbc.coorporateblinddateservice.entities.dates.MeetingTime@22155873, com.cbc.coorporateblinddateservice.entities.dates.MeetingTime@2b17a92a, com.cbc.coorporateblinddateservice.entities.dates.MeetingTime@196ad44, com.cbc.coorporateblinddateservice.entities.dates.MeetingTime@314fd6ef]
Hibernate: select meetingtim0_.id as id1_1_, meetingtim0_.meeting_date as meeting_2_1_, meetingtim0_.end_time as end_time3_1_, meetingtim0_.meeting_name as meeting_4_1_, meetingtim0_.start_time as start_ti5_1_ from meeting_times meetingtim0_

UPDATE

Controller:

@CrossOrigin(origins = "http://localhost:8080")
@RestController
@RequestMapping("api/meetingTime")
public class MeetingTimeController {

    @Autowired
    MeetingTimeService meetingTimeService;

    @GetMapping(value = "/" )
    public void getAllTimes(){
        meetingTimeService.findAllMeetingTimes();
    }



}

Save method for meetingSettings and meetingTime:

    @PostMapping("/")
    public void saveMeeting(@RequestBody MeetingsSetting meetingsSetting){
        meetingsSetting.getMeetingTime()
                .forEach(mt -> mt.setMeeting_name(meetingsSetting.getMeetingName()));
        // ...
        meetingSettingService.saveMeeting(meetingsSetting);

    }


}

this is inside meetingSettingCOntroller

This is the outcome:

{
        "id": 35,
        "date": "2021-06-21",
        "startTime": "11:01",
        "meeting_name": "Testeriuds",
        "endTime": "11:01",
        "meetingName": {
            "id": 17,
            "meetingName": "Testeriuds",
            "meetingUrl": null,
            "meetingPw": "",
            "meetingTime": [
                {
                    "id": 37,
                    "date": "2021-05-31",
                    "startTime": "15:30",
                    "meeting_name": "Testeriuds",
                    "endTime": "16:30",

THis error comes when I make the request from axios. But still shows data on the console:

java.lang.StackOverflowError: null
    at java.base/java.io.IOException.<init>(IOException.java:81) ~[na:na]
    at com.fasterxml.jackson.core.JacksonException.<init>(JacksonException.java:26) ~[jackson-core-2.12.3.jar:2.12.3]
    at com.fasterxml.jackson.core.JsonProcessingException.<init>(JsonProcessingException.java:25) ~[jackson-core-2.12.3.jar:2.12.3]
    at com.fasterxml.jackson.core.JsonProcessingException.<init>(JsonProcessingException.java:38) ~[jackson-core-2.12.3.jar:2.12.3]
    at com.fasterxml.jackson.databind.JsonMappingException.<init>(JsonMappingException.java:245) ~[jackson-databind-2.12.3.jar:2.12.3]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:785) ~[jackson-databind-2.12.3.jar:2.12.3]
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.12.3.jar:2.12.3]
    at com.fasterxml.jackson.databind.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:728) ~[jackson-databind-2.12.3.jar:2.12.3]
    at com.fasterxml.jackson.databind.ser.std.BeanSerializerBase.serializeFields(BeanSerializerBase.java:770) ~[jackson-databind-2.12.3.jar:2.12.3]
    at com.fasterxml.jackson.databind.ser.BeanSerializer.serialize(BeanSerializer.java:178) ~[jackson-databind-2.12.3.jar:2.12.3]

Answer 1

Have your @CrossOrigin match the host requested by axios. Also make your controller endpoint return something, not just call the method:

@CrossOrigin(origins = "http://localhost:8081") // <-- because axios did 8081
@RestController
@RequestMapping("api/meetingTime")
public class MeetingTimeController {

    @Autowired
    MeetingTimeService meetingTimeService;

    @GetMapping(value = "/" )
    public List<MeetingTime> getAllTimes(){             // removed void return type
        return meetingTimeService.findAllMeetingTimes(); // <-- added return here
    }

}

Answer 2

So the final error I had is called infinite recursion and can happen in Bidirectional Entity Relationship. One fix I had found was to put the @JsonManagedReference in the Entity which has the ManytoOne annotation in my case

MeetingSetting was looking like this:

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

And meetingTime is like this:

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

Maye there is a better solution and I would be grateful if someone would tell me if my solution is correct or a bad choice.