Date format customisation is ignored if custom instantiation is used

[m0mus]

Use case:

import java.time.LocalDate;
import java.util.Locale;

import javax.json.bind.Jsonb;
import javax.json.bind.JsonbBuilder;
import javax.json.bind.JsonbConfig;
import javax.json.bind.annotation.JsonbCreator;
import javax.json.bind.annotation.JsonbDateFormat;
import javax.json.bind.annotation.JsonbProperty;

public class CustomDateFormatSample {
    public static final String JSON_DATE = "{\"localDate\":\"05-09-2017\"}";

    public static final class DateProperty {
        @JsonbDateFormat(value = "dd-MM-yyyy", locale = "nl-NL")
        public LocalDate localDate = LocalDate.now();

        @Override
        public String toString() {
            return String.format("DateProperty[%s]", localDate);
        }
    }

    public static final class DateConstructor {
        @JsonbDateFormat(value = "dd-MM-yyyy", locale = "nl-NL")
        public LocalDate localDate;

        @JsonbCreator
        public DateConstructor(@JsonbProperty("localDate") LocalDate localDate) {
            this.localDate = localDate;
        }

        /*- This has the same error as the constructor without @JsonbDateFormat
        @JsonbCreator
        public DateConstructor(@JsonbProperty("localDate") @JsonbDateFormat(value = "dd-MM-yyyy", locale = "nl-NL") LocalDate localDate) {
            this.localDate = localDate;
        }
        */

        @Override
        public String toString() {
            return String.format("DateConstructor[%s]", localDate);
        }
    }

    public static final class DateFactory {
        public LocalDate localDate;

        private DateFactory(LocalDate localDate) {
            this.localDate = localDate;
        }

        @JsonbCreator
        public static DateFactory withLocalDate(@JsonbProperty("localDate") LocalDate localDate) {
            return new DateFactory(localDate);
        }

        @Override
        public String toString() {
            return String.format("DateFactory[%s]", localDate);
        }
    }

    public static void main(String[] args) {

        try {
            System.out.println("Handle class with plain date field with custom format");
            System.out.println();
            handleClassWithPlainDateField();
            System.out.println();
        } catch (Exception e) {
            System.out.println();
            System.out.println("Exception handling class with plain date field with custom format:");
            e.printStackTrace();
            System.out.println();
        }

        try {
            System.out.println(
                    "Handle class with plain date field with custom format set through JsonbCreator constructor");
            System.out.println();
            handleClassWithPlainDateFieldSetThroughJsonbCreatorConstructor();
            System.out.println();
        } catch (Exception e) {
            System.out.println();
            System.out.println(
                    "Exception handling class with plain date field with custom format set through JsonbCreator constructor:");
            e.printStackTrace();
            System.out.println();
        }

        try {
            System.out.println(
                    "Handle class with plain date field with custom format set through JsonbCreator factory method");
            System.out.println();
            handleClassWithPlainDateFieldSetThroughJsonbCreatorFactoryMethod();
            System.out.println();
        } catch (Exception e) {
            System.out.println();
            System.out.println(
                    "Exception handling class with plain date field with custom format set through JsonbCreator factory method:");
            e.printStackTrace();
            System.out.println();
        }
    }

    private static void handleClassWithPlainDateField() {
        Jsonb jsonb = JsonbBuilder.create();

        DateProperty dateProperty = new DateProperty();
        System.out.println(jsonb.toJson(dateProperty));
        DateProperty datePropertyFromJson = jsonb.fromJson(JSON_DATE, DateProperty.class);
        System.out.println(datePropertyFromJson);
        System.out.println();
    }

    private static void handleClassWithPlainDateFieldSetThroughJsonbCreatorConstructor() {
        Jsonb jsonb = JsonbBuilder.create();

        DateConstructor dateConstructor = new DateConstructor(LocalDate.now());
        System.out.println(jsonb.toJson(dateConstructor));
        /*
         * Exception on the next line. The AbstractDateTimeDeserializer does not use a
         * custom date formatter, and tries to parse JSON_DATE with
         * LocalDateTypeDeserializer.parseDefault as ISO_LOCAL_DATE.
         */
        DateConstructor dateConstructorFromJson = jsonb.fromJson(JSON_DATE, DateConstructor.class);
        System.out.println(dateConstructorFromJson);
        System.out.println();
    }

    private static void handleClassWithPlainDateFieldSetThroughJsonbCreatorFactoryMethod() {
        /*
         * With the custom date format through an annotation on the field fails like in
         * the previous examples. Check here with the custom date format set through the
         * JsonbConfig.
         */
        JsonbConfig config = new JsonbConfig().withDateFormat("dd-MM-yyyy", new Locale("nl", "NL"));
        Jsonb jsonb = JsonbBuilder.create(config);

        DateFactory dateFactory = DateFactory.withLocalDate(LocalDate.now());
        System.out.println(jsonb.toJson(dateFactory));
        /*
         * Exception on the next line. The AbstractDateTimeDeserializer does not use a
         * custom date formatter, and tries to parse JSON_DATE with
         * LocalDateTypeDeserializer.parseDefault as ISO_LOCAL_DATE.
         */
        DateFactory dateFactoryFromJson = jsonb.fromJson(JSON_DATE, DateFactory.class);
        System.out.println(dateFactoryFromJson);
        System.out.println();
    }
}

[bravehorsie]

Fixing introspecting creator parameters in attached pull request, I am not sure though we should also merge customization from property field / getter / setter.