com.amazonaws.services.dynamodbv2.datamodeling

Interface AttributeTransformer

All Known Implementing Classes:

AttributeTransformerChain

public interface AttributeTransformer

A hook allowing a custom transform/untransform of the raw attribute values immediately before writing them into DynamoDB and immediately after reading them out of DynamoDB, but with extra context about the model class not available at the raw AmazonDynamoDB level.

This interface contains both a transform method and a corresponding untransform method. These methods SHOULD be inverses, such that untransform(transform(value)) == value.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	AttributeTransformer.Parameters<T> Parameters for the transform and untransform methods, so we don't have to break the interface in order to add additional parameters.

Method Summary

Modifier and Type	Method and Description
Map<String,AttributeValue>	transform(AttributeTransformer.Parameters<?> parameters) Transforms the input set of attribute values derived from the model object before writing them into DynamoDB.
Map<String,AttributeValue>	untransform(AttributeTransformer.Parameters<?> parameters) Untransform the input set of attribute values read from DynamoDB before creating a model object from them.

Method Detail

transform

Map<String,AttributeValue> transform(AttributeTransformer.Parameters<?> parameters)

Transforms the input set of attribute values derived from the model object before writing them into DynamoDB.

Parameters:

parameters - transformation parameters

Returns:

the transformed attribute value map

untransform

Map<String,AttributeValue> untransform(AttributeTransformer.Parameters<?> parameters)

Untransform the input set of attribute values read from DynamoDB before creating a model object from them.

Parameters:

parameters - transformation parameters

Returns:

the untransformed attribute value map