CODEWITHSUNDEEP
javahibernatepersistence
Razikus
Razikus

Reputation: 146

Entity with associated entity to DTO

I want to ask about a good practice to convert Entity with associated entities to DTO's.

So, for example i have 3 enities:

@Entity
@Table
public class First {
    @Id
    private int id;

    @OneToMany(mappedBy = "first")
    ...
    private List<Second> second;

    @ManyToOne
    ...
    private Third third;


@Entity
@Table
public class Second {
    @Id
    private int id;

    @ManyToOne
    ...
    private First first;

    @OneToMany(mappedBy = "second")
    ...
    private List<Third> third;



@Entity
@Table
public class Third {
    @Id
    private int id;

    @ManyToOne
    ...
    private Second second;

    @OneToMany(mappedBy = "third")
    ...
    private List<First> first;

What is the best practice to convert all of these to DTO's? I don't want to use external libraries.

Like you see the problem is with recurrency of it and nested assotations.

Greetings.

Edit: Can somebody give me the names of libraries for mapping DTO used by himself?

Upvotes: 0

Views: 619

Answers (1)

Ano
Ano

Reputation: 96

This might help:

I recommend to use the custom dto to avoid cycles ( causes StackOverFlowError). Advantage to manage the content you are transferring. Using the entity class above, i constructed the dto below.

I have dependency for lombok like
"org.projectlombok" % "lombok" % lombokVersion

in my build.

Constructed my custom DTO 

@Data
public class FirstDTO implements Jsonable {
   protected String id; 
   protected ThirdDTO third;

   public FirstDTO(){}

   @JsonCreator
   public FirstDTO(@JsonProperty("id") String id,
                     @JsonProperty("third") Third third){
          this.id = id;
          this.third = third;
     }
}

Upvotes: 2

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