How to change JSON representation for single value java object?

Question

I had a class like:

public class EmailAddress {
   public String value;

   public String tld() {...}
   public String host() {...}
   public String mailbox() {...}
}

Now I use this class in an Object / Entity:

@Entity
public class Customer {
    public String name;
    public EmailAddress mail;
}

Now, when I do a rest service for Customer, I get this format:

{
    "id": 1,
    "name": "Test",
    "email": {
        "value": "test@test.de"
    }
}

But I only want "email": "test@test.de"

{
    "id": 1,
    "name": "Test",
    "email": "test@test.de"
}

What I must do? I use Spring Boot and Hibernate Entities.

Thank you for any support

Answer 1

I found an other easier solution, use a JsonSerializer on the entity Property:

@JsonSerialize(using = EmailAddressSerializer.class)
private EmailAddress email;

The serializer class:

public class EmailAddressSerializer extends StdSerializer<EmailAddress> {

    public EmailAddressSerializer() {
        super(EmailAddress.class);
    }

    protected EmailAddressSerializer(Class<EmailAddress> t) {
        super(t);
    }

    @Override
    public void serialize(EmailAddress email,
                          JsonGenerator jsonGenerator,
                          SerializerProvider serializerProvider) throws IOException {
        jsonGenerator.writeString(email.value);
    }
}