amazon-dynamodb - 没有自定义编组器或 @DynamoDBDocument 注释，无法解组到类型 d

Question

我正在尝试实现自定义类型转换器，但由于上面的错误消息而未能这样做。使用 - deprecated - marshallers 按预期工作

我想知道是否有办法使用@DynamoDBTypeConverted 实现转换，或者我是否被@DynamoDBMarshalling 困住了。

package com.acme;

import com.amazonaws.services.dynamodbv2.datamodeling.*;
import com.amazonaws.services.dynamodbv2.datamodeling.marshallers.ObjectToMapMarshaller;
import com.amazonaws.services.dynamodbv2.datamodeling.unmarshallers.ObjectUnmarshaller;
import com.amazonaws.services.dynamodbv2.model.AttributeValue;

import java.util.Objects;

@DynamoDBDocument
public class MyDynamoDBEntity {
    @DynamoDBTypeConverted(converter = Id.Converter.class)
    //@DynamoDBMarshalling(marshallerClass = Id.Marshaller.class)
    protected Id id;

    public Id getId() {
        return id;
    }

    public void setId(final Id id) {
        this.id = id;
    }

    public static class Converter implements DynamoDBTypeConverter<AttributeValue, MyDynamoDBEntity> {
        private ItemConverter itemConverter = ConversionSchemas.V2.getConverter(new ConversionSchema.Dependencies());

        @Override
        public AttributeValue convert(final MyDynamoDBEntity object) {
            if (object == null) {
                return null;
            }

            return new ObjectToMapMarshaller(itemConverter).marshall(object);
        }

        @Override
        public MyDynamoDBEntity unconvert(AttributeValue value) {
            try {
                // non empty object
                if (value.getM() != null && value.getM().size() > 0) {
                    final ObjectUnmarshaller unmarshaller = new ObjectUnmarshaller(itemConverter, MyDynamoDBEntity.class);

                    return (MyDynamoDBEntity) unmarshaller.unmarshall(value);
                } else {
                    return null;
                }
            } catch (Exception e) {
                throw new RuntimeException(e);
            }
        }
    }

    public static class Id {
        private String value;

        public Id(final String value) {
            this.value = value;
        }

        public String toValue() {
            return value;
        }

        public static Id of(String s) {
            return new Id(s);
        }

        public static class Converter implements DynamoDBTypeConverter<String, Id> {
            @Override
            public String convert(final Id value) {
                return value.toValue();
            }

            @Override
            public Id unconvert(final String value) {
                return Id.of(value);
            }
        }

        public static class Marshaller implements DynamoDBMarshaller<Id> {
            @Override
            public String marshall(final Id value) {
                return value.toValue();
            }

            @Override
            public Id unmarshall(final Class<Id> clazz, final String value) {
                return Id.of(value);
            }
        }

        @Override
        public boolean equals(final Object o) {
            if (this == o) return true;
            if (o == null || getClass() != o.getClass()) return false;
            final Id id = (Id) o;
            return Objects.equals(value, id.value);
        }

        @Override
        public int hashCode() {
            return Objects.hash(value);
        }
    }
}

感谢您为我指明正确的方向。

标签： amazon-dynamodbaws-sdk