How to save a list in an object using Java?

Question

Before saving

After saving

@Entity
@JsonIgnoreProperties({"hibernateLazyInitializer", "handler"})
public class Notification {


  @Id
    @GeneratedValue(strategy = GenerationType.AUTO)
    private Long notificationId;
    private Long businessId;
    private String actionBy;
    private String date;
    private String notification;
    public ArrayList<UserNotification> user;

  //constructor here

  //getters setters here
}

and UserNotification.java is

public class UserNotification {
private Long id;
private String user;
private String notifCount;
//getters setters here
}

I don't know why is it returning null. At what point I made a mistake?

EDIT:

 var usersObj=[];
        BusinessRoleService.getByBusinessId($sessionStorage.businessRole.business).then(function(response){
            if(response.status==200){
                for(var x=0;x<response.data.length;x++){
                    usersObj.push({id: x, user: response.data[x].userId, notifCount: $scope.notification});
                }


            }
        });

        var obj = {
            "businessId": businessId,
            "actionBy": user,
            "date": date,
            "notification": user+" "+action,
            "user": usersObj
        }

then I will pass the obj to my service to save

This is what my database looks like after saving

Your array name is `user`, but it should be `users`, and look at this [answer](https://stackoverflow.com/a/2154640/5686835) — Ron Nabuurs, Apr 25 '18 at 11:10
Update your question and provide the full Notification and UserNotification class definitions (with every annotation) — Guillaume Georges, Apr 25 '18 at 11:21
Why is UserNotification not an @Entity? Also you need to tell JPA what kind of relationship ties Notification to UserNotification. My guess is there's a bunch of annotations missing on both classes. Read this :https://en.wikibooks.org/wiki/Java_Persistence/OneToMany — Guillaume Georges, Apr 25 '18 at 11:29
@Mark https://stackoverflow.com/questions/25713884/jpa-transient-annotation-and-json/25743802 check that question — User4567, Apr 25 '18 at 11:36
I don't want to have a table UserNotification. I just want Notification table only — Mark, Apr 25 '18 at 11:39
How are you going to store a list of UserNotification in your Notification table? Give us your table structure please. — Guillaume Georges, Apr 25 '18 at 11:42
You need to provide the structure of the Notification table. In what kind of field are you storing your `user` property? Otherwise we can't help you. — Guillaume Georges, Apr 25 '18 at 11:49
@RogerC I used JPA so it generated on its own. As I checked my database it is TINYBLOB — Mark, Apr 25 '18 at 11:53

Guillaume Georges · Answer 1 · 2018-04-25T11:46:49.940

2

In your Notification Java object, the user property has the @Transient annotation. Which means it won't be persisted.

So, the property is null in the response of your controller.

As other have said, you also have a difference in your JavaScript and Java structure. In your Notification java object, your list should be named users

After your last edit :

Why is UserNotification not an @Entity? Also you need to tell JPA what kind of relationship ties Notification to UserNotification. My guess is there's a bunch of annotations missing on both classes. Read this :https://en.wikibooks.org/wiki/Java_Persistence/OneToMany

edited Apr 25 '18 at 11:46

answered Apr 25 '18 at 11:10

Guillaume Georges

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what shall I do then? – Mark Apr 25 '18 at 11:10
Remove @Transient – Fatmajk Apr 25 '18 at 11:11
In your IndexController change list name users to user – User4567 Apr 25 '18 at 11:12
it is still null – Mark Apr 25 '18 at 11:13
@Lakshman damn didn't notice that one. it saves now but it is empty – Mark Apr 25 '18 at 11:14
Please check the post again. It saves now but empty – Mark Apr 25 '18 at 11:19
@Mark see this question, it may be helpful https://stackoverflow.com/questions/25713884/jpa-transient-annotation-and-json/25743802 – User4567 Apr 25 '18 at 11:34
I added entity but it still don't save – Mark Apr 25 '18 at 11:37
where are you saving this object, did you checked in your database? – User4567 Apr 25 '18 at 11:42
the second image was returned and save like that. I am saving it in Notification table – Mark Apr 25 '18 at 11:46
Let us [continue this discussion in chat](https://chat.stackoverflow.com/rooms/169756/discussion-between-mark-and-lakshman). – Mark Apr 25 '18 at 11:53

How to save a list in an object using Java?

1 Answers1