Jackson JSON serializer for the DynamoDB V2 SDK's AttributeValue

AttributeValueSerializer.java

import java.io.IOException;
import java.math.BigDecimal;
import java.util.List;
import java.util.Map;

import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.JsonSerializer;
import com.fasterxml.jackson.databind.SerializerProvider;

import software.amazon.awssdk.core.SdkBytes;
import software.amazon.awssdk.core.util.DefaultSdkAutoConstructList;
import software.amazon.awssdk.core.util.DefaultSdkAutoConstructMap;
import software.amazon.awssdk.services.dynamodb.model.AttributeValue;

/**
 * <p>Title: AttributeValueSerializer</p>
 * <p>Description: Jackson JSON serializer for the DynamoDB V2 SDK's {@link software.amazon.awssdk.services.dynamodb.model.AttributeValue}</p>
 * <p>Author: Whitehead</p>
 */
public class AttributeValueSerializer extends JsonSerializer<AttributeValue> {
	public static final DefaultSdkAutoConstructMap<?,?> EMPTY_ATTR_MAP = DefaultSdkAutoConstructMap.getInstance();
	public static final DefaultSdkAutoConstructList<?> EMPTY_ATTR_LIST = DefaultSdkAutoConstructList.getInstance();
	
	public static final JsonSerializer<AttributeValue> INSTANCE = new AttributeValueSerializer();
	
	private AttributeValueSerializer() {
		
	}

	@Override
	public void serialize(AttributeValue av, JsonGenerator gen, SerializerProvider serializers) throws IOException {
		if (av == null) {
			gen.writeNull();
		} else {
			if (av.m() != EMPTY_ATTR_MAP) {
				gen.writeStartObject();
				Map<String, AttributeValue> map = av.m();
				for(Map.Entry<String, AttributeValue> entry : map.entrySet()) {
					gen.writeFieldName(entry.getKey());
					serialize(entry.getValue(), gen, serializers);
				}
				gen.writeEndObject();
			} else if (av.l() != EMPTY_ATTR_LIST) {
				List<AttributeValue> list = av.l();
				gen.writeStartArray();
				for(AttributeValue a : list) {
					serialize(a, gen, serializers);
				}
				gen.writeEndArray();
			} else if (av.s() != null) {		
				gen.writeString(av.s());
			} else if (av.n() != null) {
				gen.writeNumber(new BigDecimal(av.n()));
			} else if (av.bool() != null) {
				gen.writeBoolean(av.bool());
			} else if (av.nul() != null && av.nul()) {
				gen.writeNull();
			} else if (av.b() != null) {
				gen.writeBinary(av.b().asByteArray());
			} else if (av.ss() != EMPTY_ATTR_LIST) {
				List<String> list = av.ss();
				int size = list.size();
				gen.writeStartArray(size);
				for(int i = 0; i < size; i++) {
					gen.writeString(list.get(i));
				}
				gen.writeEndArray();				
			} else if (av.bs() != EMPTY_ATTR_LIST) {
				List<SdkBytes> list = av.bs();
				int size = list.size();
				gen.writeStartArray(size);
				for(int i = 0; i < size; i++) {
					gen.writeBinary(list.get(i).asByteArray()); 
				}
				gen.writeEndArray();				
			} else if (av.ns() != EMPTY_ATTR_LIST) {
				List<String> list = av.ns();
				int size = list.size();
				gen.writeStartArray(size);
				for(int i = 0; i < size; i++) {
					gen.writeNumber(new BigDecimal(list.get(i))); 
				}
				gen.writeEndArray();				
			} else if (av.nul() != null) {
				gen.writeNull();
			} 
//			else {
//				System.err.println("MISSED DATA TYPE: " + av);
//			}
		}
	}
}

Thanks for sharing! I also had to add the following override to get it working

   @Override
    public Class<AttributeValue> handledType() {
        return AttributeValue.class;
    }

Thanks !