Class com.fasterxml.jackson.datatype.joda.deser.DateTimeDeserializer has no default (no arg) constructor

Question

I am getting an error - 'Class com.fasterxml.jackson.datatype.joda.deser.DateTimeDeserializer has no default (no arg) constructor' while I am trying to call restangular for post request. When I call the method it goes in the error block.

Restangular.all('tests').post($scope.test).then(function (data) {
                    $scope.test.id = data.id;
                    $location.path($location.path() + data.id).replace();
                }, function (error) {
                    $scope.exceptionDetails = validationMapper(error);
                });

I am using jackson-datatype-joda - 2.6.5

The entity class used in this method as follows -

@Data
@JsonInclude(JsonInclude.Include.NON_NULL)
@Entity
@Table(name = "Test")
@EqualsAndHashCode(of = "id", callSuper = false)
@ToString(exclude = {"keywords", "relevantObjectIds"})
public class Test {
    @Id
    @Column(unique = true, length = 36)
    private String id;

    @NotBlank
    @NotNull
    private String name;

    @Transient
    private List<Testabc> Testabcs = new ArrayList<>();

}

The entity class used in above entity Testabc class as follows

@Data
@JsonInclude(JsonInclude.Include.NON_NULL)
@Slf4j
@Entity
@Table(name = "Test_abc")
@EqualsAndHashCode(of = "id", callSuper = false)
public class Testabc{
    @Id
    @Column(unique = true, length = 36)
    @NotNull
    private String id = UUID.randomUUID().toString();

 @Type(type = "org.jadira.usertype.dateandtime.joda.PersistentDateTime")
    @JsonDeserialize(using = DateTimeDeserializer.class)
    @JsonSerialize(using = DateTimeSerializer.class)
    private DateTime createdOn;

    @ManyToOne(fetch = FetchType.EAGER)
    @JoinColumn(name = "Id")
    @NotNull
    private t1 pid;

    private long originalSize;
}

Finally resource class where I am requesting to create test data -

@ApiOperation(value = "Create new Test", notes = "Create a new Test and return with its unique id", response = Test.class)
    @POST
    @Timed
    public Test create(Test newInstance) {
        return super.create(newInstance);
    }

I have tried to add this @JsonIgnoreProperties(ignoreUnknown = true) annotation on entity class, but it doesn't work.

Can anyone help to resolve this problem?

Answer 1

Looking at the latest sources of DateTimeDeserializer you can easily see that it does not have a no-arg constructor, which seems to be required by the framework. This is also indicated in both the linked questions: joda.time.DateTime deserialization error & Jackson, Retrofit, JodaTime deserialization

Since you want to use only an annotation based solution, a possible workaround would be to create your own deserializer which extends the DateTimeDeserializer and provides a nor-arg constructor.

1) MyDateTimeSerializer

import com.fasterxml.jackson.datatype.joda.cfg.FormatConfig;
import com.fasterxml.jackson.datatype.joda.deser.DateTimeDeserializer;
import org.joda.time.DateTime;

public class MyDateTimeDeserializer extends DateTimeDeserializer {
    public MyDateTimeDeserializer() {
        // no arg constructor providing default values for super call
        super(DateTime.class, FormatConfig.DEFAULT_DATETIME_PARSER);
    }
}

2) AClass using the custom deserializer

import com.fasterxml.jackson.databind.annotation.JsonDeserialize;
import com.fasterxml.jackson.databind.annotation.JsonSerialize;
import com.fasterxml.jackson.datatype.joda.ser.DateTimeSerializer;
import org.joda.time.DateTime;
import org.joda.time.DateTimeZone;

public class AClass {

    @JsonSerialize(using = DateTimeSerializer.class) // old serializer
    @JsonDeserialize(using = MyDateTimeDeserializer.class) // new deserializer
    private DateTime createdOn = DateTime.now(DateTimeZone.UTC); // some dummy data for the sake of brevity

    public DateTime getCreatedOn() {
        return createdOn;
    }

    public void setCreatedOn(DateTime createdOn) {
        this.createdOn = createdOn;
    }
}

3) Unit test

import com.fasterxml.jackson.databind.ObjectMapper;
import org.junit.Test;

import static org.hamcrest.CoreMatchers.equalTo;
import static org.hamcrest.CoreMatchers.is;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertThat;

public class ATest {
    @Test
    public void testSomeMethod() throws Exception {
        // Jackson object mapper to test serialization / deserialization
        ObjectMapper objectMapper = new ObjectMapper();

        // our object
        AClass initialObject = new AClass();

        // serialize it
        String serializedObject = objectMapper.writeValueAsString(initialObject);

        // deserialize it
        AClass deserializedObject = objectMapper.readValue(serializedObject, AClass.class);

        // check that the dates are equal (no equals implementation on the class itself...)
        assertThat(deserializedObject.getCreatedOn(), is(equalTo(initialObject.getCreatedOn())));
    }
}

Answer 2

This deserializer was never meant to be used by annotations; and as others have mentioned, cannot. In general you really should just add/register JodaModule and serializer/deserializer gets added as expected.

I am not sure why you would not want to go that route; it might be worth expanding on why this solution (or registering deserializer you get by DateTimeDeserializer.forType(ReadableDateTime.class) through your custom module) is not applicable.