CODEWITHSUNDEEP
javajsonhibernatejpa
Thadeu Melo
Thadeu Melo

Reputation: 991

Hibernate mapping internal class, Error "Could not determine type for: timeStamps"

I have Entity "Task" that needs to have an internal component called "timestamps" that holds values for when the task was submitted, started and completed. 

@Entity
public class Task {
    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    private Integer Id;
    private String Status;
    private Timestamps timestamps;
    // getters setters
}

Then I created the Timestamps class

public class Timestamps {
 private Timestamp submitted;
 private Timestamp started;
 private Timestamp completed;
 //getter and setters
}

How do I make this mapping so when I retrieve the information in JSON format I have something like this?

# task
{
    "task": # ASCII string
    "status": # one of "submitted", "started", "completed"
    "timestamps": {
    "submitted": # unix/epoch time
    "started": # unix/epoch time or null if not started
    "completed": # unix/epoch time or null if not completed
    }
}

Upvotes: 0

Views: 60

Answers (2)

John Camerin
John Camerin

Reputation: 722

You can put the @Embeddable annotation on Timestamps. Hibernate will map the fields as columns in the same table. You might also need an @Embedded on the Timestamps field in Task (I cant remeber for certain if both sides need an annotation).

Upvotes: 1

Mohsen
Mohsen

Reputation: 4643

If you don't want to persist Timestamps in DB and just use it In DTO This will helps you:

@Transient annotation is used to indicate that a field is not to be persisted in the database.

@Entity
public class Task {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer Id;
private String Status;
@Transient
private Timestamps timestamps;
// getters setters
}

If you want to persist Timestamps as a relation you should do something like this:

@Entity
public class Timestamps {
 @Id
 @GeneratedValue(strategy = GenerationType.IDENTITY)
 private Integer Id;
 private Timestamp submitted;
 private Timestamp started;
 private Timestamp completed;
 //getter and setters
}

@Entity
public class Task {
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
private Integer Id;
private String Status;
@ManyToOne
private Timestamps timestamps;
// getters setters
}

Upvotes: 1

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