Jackson serialize only interface methods

Question

I have one object A with some methods ma, mb, mc and this object implements an interface B with only ma and mb.

When I serialize B I expect only ma and mb as a json response but I get as well mc.

I'd like to automatize this behaviour so that all the classes I serialize get serialized based on the interface and not on the implementation.

How should I do that?

Example:

public interface Interf {
    public boolean isNo();

    public int getCountI();

    public long getLonGuis();
}

Implementation:

public class Impl implements Interf {

    private final String patata = "Patata";

    private final Integer count = 231321;

    private final Boolean yes = true;

    private final boolean no = false;

    private final int countI = 23;

    private final long lonGuis = 4324523423423423432L;

    public String getPatata() {
        return patata;
    }


    public Integer getCount() {
        return count;
    }


    public Boolean getYes() {
        return yes;
    }


    public boolean isNo() {
        return no;
    }


    public int getCountI() {
        return countI;
    }

    public long getLonGuis() {
        return lonGuis;
    }

}

Serialization:

    ObjectMapper mapper = new ObjectMapper();

    Interf interf = new Impl();
    String str = mapper.writeValueAsString(interf);

    System.out.println(str);

Response:

 {
    "patata": "Patata",
    "count": 231321,
    "yes": true,
    "no": false,
    "countI": 23,
    "lonGuis": 4324523423423423500
} 

Expected response:

 {
    "no": false,
    "countI": 23,
    "lonGuis": 4324523423423423500
 } 

Answer 1

Just annotate your interface such that Jackson constructs data fields according to the interface's class and not the underlying object's class.

@JsonSerialize(as=Interf.class)
public interface Interf {
  public boolean isNo();
  public int getCountI();
  public long getLonGuis();
}

Answer 2

You have two options:

1) put @JsonSerialize annotation on your interface (see @broc.seib answer)

2) or use specific writer for the serialization (as of Jackson 2.9.6):

ObjectMapper mapper = new ObjectMapper();
String str = mapper.writerFor(Interf.class).writeValueAsString(interf);