com.amazonaws.services.dynamodbv2.datamodeling

Annotation Type DynamoDBTyped

@Inherited
 @Retention(value=RUNTIME)
 @Target(value={TYPE,FIELD,METHOD,ANNOTATION_TYPE})
public @interface DynamoDBTyped

Annotation to override the standard attribute type binding.

 @DynamoDBTyped(DynamoDBAttributeType.S)
 public MyObject getMyObject()
 

Standard Types

Standard types do not require the annotation if applying the default attribute binding for that type.

String/S types,

• Character/char
• String
• URL
• URI
• Calendar
• Currency
• Date
• Locale
• TimeZone
• UUID
• S3Link

Number/N types,

• BigDecimal
• BigInteger
• Boolean/boolean
• Byte/byte
• Double/double
• Float/float
• Integer/int
• Long/long
• Short/short

Binary/B types,

• ByteBuffer
• byte[]

DynamoDBTypeConverter

A custom type-converter maybe applied to any attribute, either by annotation or by overriding the standard type-converter factory.

 DynamoDBMapperConfig config = DynamoDBMapperConfig.builder()
     .withTypeConverterFactory(DynamoDBTypeConverterFactory.standard().override()
         .with(String.class, MyObject.class, new StringToMyObjectConverter())
         .build())
     .build();
 

If the converter being applied is already a supported data type and the conversion is of the same attribute type, for instance, Date to String to S, the annotation may be omited. The annotation is require for all non-standard types or if the attribute type binding is being overriden.

AttributeValue

Direct native conversion is supported by default in all schemas. If the attribute is a primary or index key, it must specify either B, N, or S, otherwise, it may be omited.

Boolean to BOOL

The standard V2 conversion schema will by default serialize booleans natively using the DynamoDB BOOL type.

 @DynamoDBTyped(DynamoDBAttributeType.BOOL)
 public boolean isTesting()
 

Boolean to N

The standard V1 and V2 compatible conversion schemas will by default serialize booleans using the DynamoDB N type, with a value of '1' representing 'true' and a value of '0' representing 'false'.

 @DynamoDBTyped(DynamoDBAttributeType.N)
 public boolean isTesting()
 

Enum to S

The enum type is only supported by override or custom converter. There are some risks in distributed systems when using enumerations as attributes intead of simply using a String. When adding new values to the enumeration, the enum only changes must deployed before the enumeration value can be persisted. This will ensure that all systems have the correct code to map it from the item record in DynamoDB to your objects.

 public enum Status { OPEN, PENDING, CLOSED };

 @DynamoDBTyped(DynamoDBAttributeType.S)
 public Status getStatus()
 

UUID to B

The UUID type will serialize to String/S by default in all conversion schemas. The schemas do support serializing to ByteBuffer/B by override.

 @DynamoDBTyped(DynamoDBAttributeType.B)
 public UUID getKey()
 

Set to L

The standard V1 and V2 compatible conversion schemas do not by default support non-scalar Set types. They are supported in V2. In non-supported schemas, the List/L override may be applied to any Set type.

 @DynamoDBTyped(DynamoDBAttributeType.L)
 public Set<MyObject> getMyObjects()
 

Object to M

Also supported as DynamoDBDocument.

 @DynamoDBTyped(DynamoDBAttributeType.M)
 public MyObject getMyObject()
 

May be combined with DynamoDBTypeConverted.

May be used as a meta-annotation.

See Also:

DynamoDBTypeConverted, DynamoDBTypeConverterFactory

Optional Element Summary

Optional Elements

Modifier and Type	Optional Element and Description
DynamoDBMapperFieldModel.DynamoDBAttributeType	value Use when the type of the attribute as stored in DynamoDB should differ from the standard type assigned by DynamoDBMapper.

Element Detail

value

public abstract DynamoDBMapperFieldModel.DynamoDBAttributeType value

Use when the type of the attribute as stored in DynamoDB should differ from the standard type assigned by DynamoDBMapper.

Default:

com.amazonaws.services.dynamodbv2.datamodeling.DynamoDBMapperFieldModel.DynamoDBAttributeType.NULL