software.amazon.awssdk.extensions.dynamodb.mappingclient

Interface DatabaseOperation<RequestT,ResponseT,ResultT>

Type Parameters:

RequestT - The type of the request object for the DynamoDb call in the low level DynamoDbClient.

ResponseT - The type of the response object for the DynamoDb call in the low level DynamoDbClient.

ResultT - The type of the mapped result object that will be returned by the execution of this operation.

All Known Implementing Classes:

BatchGetItem, BatchWriteItem, TransactGetItems, TransactWriteItems

public interface DatabaseOperation<RequestT,ResponseT,ResultT>

Interface for a single operation that can be executed against a mapped database. These operations do not operate on a specific table or index, and may reference multiple tables and indexes (eg: batch operations). Conceptually an operation maps 1:1 with an actual DynamoDb call. Typically a database operation will be executed by a MappedDatabase which expects a supplier: mappedDatabase.execute(() -> databaseOperation);

Method Summary

Modifier and Type	Method and Description
default ResultT	execute(DynamoDbClient dynamoDbClient, MapperExtension mapperExtension) Default implementation of a complete execution of this operation.
RequestT	generateRequest(MapperExtension mapperExtension) This method generates the request that needs to be sent to a low level DynamoDbClient.
Function<RequestT,ResponseT>	getServiceCall(DynamoDbClient dynamoDbClient) Provides a function for making the low level SDK call to DynamoDb.
ResultT	transformResponse(ResponseT response, MapperExtension mapperExtension) Takes the response object returned by the actual DynamoDb call and maps it into a higher level abstracted result object.

Method Detail

generateRequest

RequestT generateRequest(MapperExtension mapperExtension)

This method generates the request that needs to be sent to a low level DynamoDbClient.

Parameters:

mapperExtension - A MapperExtension that may modify the request of this operation. A null value here will result in no modifications.

Returns:

A request that can be used as an argument to a DynamoDbClient call to perform the operation.

getServiceCall

Function<RequestT,ResponseT> getServiceCall(DynamoDbClient dynamoDbClient)

Provides a function for making the low level SDK call to DynamoDb.

Parameters:

dynamoDbClient - A low level DynamoDbClient to make the call against.

Returns:

A function that calls DynamoDb with a provided request object and returns the response object.

transformResponse

ResultT transformResponse(ResponseT response,
                          MapperExtension mapperExtension)

Takes the response object returned by the actual DynamoDb call and maps it into a higher level abstracted result object.

Parameters:

response - The response object returned by the DynamoDb call for this operation.

mapperExtension - A MapperExtension that may modify the result of this operation. A null value here will result in no modifications.

Returns:

A high level result object as specified by the implementation of this operation.

execute

default ResultT execute(DynamoDbClient dynamoDbClient,
                        MapperExtension mapperExtension)

Default implementation of a complete execution of this operation. It performs three steps: 1) Call generateRequest() to get the request object. 2) Call getServiceCall() and call it using the request object generated in the previous step. 3) Call transformResponse() to convert the response object returned in the previous step to a high level result.

Parameters:

dynamoDbClient - A DynamoDbClient to make the call against.

mapperExtension - A MapperExtension that may modify the request or result of this operation. A null value here will result in no modifications.

Returns:

A high level result object as specified by the implementation of this operation.