Question

I have an object “A” which extends object “B” when object “A” gets serialized the fields from object “B” do not get serialized into JSON. Any Ideas? Here are my objects involved.

public class CreateNewPlayerAndLoginResponse extends EPNetResponse{
    private PlayerSession playerSession;

    public CreateNewPlayerAndLoginResponse() {
    }

    public CreateNewPlayerAndLoginResponse(Integer playerId, String playerSessionId) {
        this.playerSession = new PlayerSession(playerId, playerSessionId);
    }

    public CreateNewPlayerAndLoginResponse(EPNetErrorEnum error) {
        super(error);
    }

    public CreateNewPlayerAndLoginResponse(EPNetError error) {
        super(error);
    }

    public PlayerSession getPlayerSession() {
        return playerSession;
    }

    public void setPlayerSession(PlayerSession playerSession) {
        this.playerSession = playerSession;
    }

    @Override
    public String toString() {
        return "CreateNewPlayerAndLoginResponse{" + "playerSession=" + playerSession + '}';
    }

}

public class EPNetResponse implements Serializable{

    private EPNetError error;

    public EPNetResponse() {
    }

    public EPNetResponse(EPNetError error) {
        this.error = error;
    }

    public EPNetResponse(EPNetErrorEnum error){
        this.error = new EPNetError(error);
    }

    public EPNetError getError() {
        return error;
    }

    public void setError(EPNetError error) {
        this.error = error;
    }

    @JsonIgnore
    public boolean isError(){
        if(error == null){
            return false;
        }

        return true;
    }
}

public class EPNetError implements Serializable{
    private static final int UNEXPECTED_ERROR = 5417;
    private Integer code;
    private String message;

    public EPNetError() {
    }

    public EPNetError(EPNetErrorEnum error){
        this.code = error.getCode();
        this.message = error.getMessage();
    }

    public EPNetError(EPNetErrorEnum error, String message){
        this.code = error.getCode();
        this.message = message;
    }

    public EPNetError(String message){
        this.code = EPNetError.UNEXPECTED_ERROR;
        this.message = message;
    }

    public EPNetError(Integer code, String message) {
        this.code = code;
        this.message = message;
    }

    public Integer getCode() {
        return code;
    }

    public void setCode(Integer code) {
        this.code = code;
    }

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

}

All I get as the serialized response is

{"playerSession":null}

Even though I am 100% sure there is an error message part of the object before serialization.

Also worth mentioning I am using Jackson 1.9.2 and Jersey 1.13

Answer 1

If you are expecting ‘error’ to be included, problem is that @JsonIgnore in isError(), without any other annotations. So, add @JsonProperty next to getError() and it should be included. You may also need to add it to setError().

The problem here is that Jackson consider @JsonIgnore here to mean “ignore property ‘error'”, whereas you are probably only hoping to ignore that particular accessor.