Jackson use JsonSerialize.Inclusion.NON_NULL except for one class

@user1433372, JsonInclude is an annotation only for Jackson 2.x.

in Jackson 1.9

@JsonSerialize(include=JsonSerialize.Inclusion.NON_EMPTY)

is the same in Jackson 2.x as

@JsonInclude(JsonInclude.Include.NON_EMPTY)

With Jackson 1.9 is used @JsonSerialize(include= JsonSerialize.Inclusion.ALWAYS)

@JsonSerialize(include=Include.ALWAYS) did not compile.

With Jackson 1.x you can use @JsonSerialize(include = Inclusion.ALWAYS) and with Jackson 2.x you can use @JsonInclude(Include.ALWAYS). These annotations will override the default config from your ObjectMapper.