software.amazon.awssdk.extensions.dynamodb.mappingclient

Interface CommonOperation<ItemT,RequestT,ResponseT,ResultT>

Type Parameters:

ItemT - The modelled object that this table maps records to.

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 Subinterfaces:

IndexOperation<ItemT,RequestT,ResponseT,ResultT>, TableOperation<ItemT,RequestT,ResponseT,ResultT>

All Known Implementing Classes:

CreateTable, DeleteItem, GetItem, PutItem, Query, Scan, UpdateItem

public interface CommonOperation<ItemT,RequestT,ResponseT,ResultT>

Common interface for a single operation that can be executed against a mapped database table. These operations can be made against either the primary index of a table or a secondary index, although some implementations of this interface do not support secondary indices and will throw an exception when executed against one. Conceptually an operation maps 1:1 with an actual DynamoDb call. This interface is extended by TableOperation and IndexOperation which contain implementations of the behavior to actually execute the operation in the context of a table or secondary index and are used by MappedTable and MappedIndex respectively. By sharing this common interface operations are able to re-use code regardless of whether they are executed in the context of a primary or secondary index.

Method Summary

Modifier and Type	Method and Description
default ResultT	execute(TableSchema<ItemT> tableSchema, OperationContext context, MapperExtension mapperExtension, DynamoDbClient dynamoDbClient) Default implementation of a complete execution of this operation against either the primary or a secondary index.
RequestT	generateRequest(TableSchema<ItemT> tableSchema, OperationContext context, 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, TableSchema<ItemT> tableSchema, OperationContext context, 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(TableSchema<ItemT> tableSchema,
                         OperationContext context,
                         MapperExtension mapperExtension)

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

Parameters:

tableSchema - A TableSchema that maps the table to a modelled object.

context - An object containing the context, or target, of the command execution.

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,
                          TableSchema<ItemT> tableSchema,
                          OperationContext context,
                          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.

tableSchema - A TableSchema that maps the table to a modelled object.

context - An object containing the context, or target, of the command execution.

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(TableSchema<ItemT> tableSchema,
                        OperationContext context,
                        MapperExtension mapperExtension,
                        DynamoDbClient dynamoDbClient)

Default implementation of a complete execution of this operation against either the primary or a secondary index. 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:

tableSchema - A TableSchema that maps the table to a modelled object.

context - An object containing the context, or target, of the command execution.

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.