Jackson deserializer - change null collection to empty one

Question

I have an entity that contains collection as attribute:

public class Entity {

    @JsonProperty(value=\"homes\")
    @JsonDeserialize(as=HashSet.class, cont         


        

Answer 1

What worked for me was simply to remove the setter and make the attribute final. jackson 2 will then use the getter to modify the list.

public class Entity {

  @JsonProperty(value="homes")
  @JsonDeserialize(as=HashSet.class, contentAs=HomeImpl.class)
  private final Collection homes = new ArrayList();

  public List getHomes() {
     return homes;
  }
}

The responsible feature is USE_GETTERS_AS_SETTERS which is turned on by default: https://github.com/FasterXML/jackson-databind/wiki/Mapper-Features