Package com.amazonaws.services.dynamodbv2.datamodeling

Class AbstractDynamoDBMapper

  • All Implemented Interfaces:
    IDynamoDBMapper
    Direct Known Subclasses:
    DynamoDBMapper
    public class AbstractDynamoDBMapper
extends Object
implements IDynamoDBMapper
    Abstract implementation of IDynamoDBMapper. Convenient method forms pass through to the corresponding overload that takes a request object, which throws an UnsupportedOperationException.

    • Constructor Detail

      • AbstractDynamoDBMapper

        protected AbstractDynamoDBMapper()

    • Method Detail

      • load

        public <T> T load​(T keyObject,
                  DynamoDBMapperConfig config)
        Description copied from interface: IDynamoDBMapper
        Returns an object whose keys match those of the prototype key object given, or null if no such item exists.
        Specified by:
        load in interface IDynamoDBMapper
        Parameters:
        keyObject - An object of the class to load with the keys values to match.
        config - Configuration for the service call to retrieve the object from DynamoDB. This configuration overrides the default given at construction.

      • load

        public <T> T load​(Class<T> clazz,
                  Object hashKey,
                  Object rangeKey,
                  DynamoDBMapperConfig config)
        Description copied from interface: IDynamoDBMapper
        Returns an object with the given hash key, or null if no such object exists.
        Specified by:
        load in interface IDynamoDBMapper
        Parameters:
        clazz - The class to load, corresponding to a DynamoDB table.
        hashKey - The key of the object.
        rangeKey - The range key of the object, or null for tables without a range key.
        config - Configuration for the service call to retrieve the object from DynamoDB. This configuration overrides the default given at construction.

      • marshallIntoObject

        public <T> T marshallIntoObject​(Class<T> clazz,
                                Map<String,​AttributeValue> itemAttributes)
        Description copied from interface: IDynamoDBMapper
        Creates and fills in the attributes on an instance of the class given with the attributes given.

        This is accomplished by looking for getter methods annotated with an appropriate annotation, then looking for matching attribute names in the item attribute map.

        This method is no longer called by load/scan/query methods. If you are overriding this method, please switch to using an AttributeTransformer

        Specified by:
        marshallIntoObject in interface IDynamoDBMapper
        Parameters:
        clazz - The class to instantiate and hydrate
        itemAttributes - The set of item attributes, keyed by attribute name.

      • save

        public <T> void save​(T object,
                     DynamoDBSaveExpression saveExpression,
                     DynamoDBMapperConfig config)
        Description copied from interface: IDynamoDBMapper
        Saves an item in DynamoDB. The service method used is determined by the DynamoDBMapperConfig.getSaveBehavior() value, to use either AmazonDynamoDB.putItem(PutItemRequest) or AmazonDynamoDB.updateItem(UpdateItemRequest):
        • UPDATE (default) : UPDATE will not affect unmodeled attributes on a save operation and a null value for the modeled attribute will remove it from that item in DynamoDB. Because of the limitation of updateItem request, the implementation of UPDATE will send a putItem request when a key-only object is being saved, and it will send another updateItem request if the given key(s) already exists in the table.
        • UPDATE_SKIP_NULL_ATTRIBUTES : Similar to UPDATE except that it ignores any null value attribute(s) and will NOT remove them from that item in DynamoDB. It also guarantees to send only one single updateItem request, no matter the object is key-only or not.
        • CLOBBER : CLOBBER will clear and replace all attributes, included unmodeled ones, (delete and recreate) on save. Versioned field constraints will also be disregarded.
        Any options specified in the saveExpression parameter will be overlaid on any constraints due to versioned attributes.
        Specified by:
        save in interface IDynamoDBMapper
        Parameters:
        object - The object to save into DynamoDB
        saveExpression - The options to apply to this save request
        config - The configuration to use, which overrides the default provided at object construction.
        See Also:
        DynamoDBMapperConfig.SaveBehavior

      • delete

        public void delete​(Object object)
        Description copied from interface: IDynamoDBMapper
        Deletes the given object from its DynamoDB table using the default configuration.
        Specified by:
        delete in interface IDynamoDBMapper

      • delete

        public <T> void delete​(T object,
                       DynamoDBDeleteExpression deleteExpression,
                       DynamoDBMapperConfig config)
        Description copied from interface: IDynamoDBMapper
        Deletes the given object from its DynamoDB table using the provided deleteExpression and provided configuration. Any options specified in the deleteExpression parameter will be overlaid on any constraints due to versioned attributes.
        Specified by:
        delete in interface IDynamoDBMapper
        deleteExpression - The options to apply to this delete request
        config - Config override object. If DynamoDBMapperConfig.SaveBehavior.CLOBBER is supplied, version fields will not be considered when deleting the object.

      • batchSave

        public List<DynamoDBMapper.FailedBatch> batchSave​(Object... objectsToSave)
        Description copied from interface: IDynamoDBMapper
        Saves the objects given using one or more calls to the AmazonDynamoDB.batchWriteItem(BatchWriteItemRequest) API. No version checks are performed, as required by the API.

        This method ignores any SaveBehavior set on the mapper, and always behaves as if SaveBehavior.CLOBBER was specified, as the AmazonDynamoDB.batchWriteItem() request does not support updating existing items. *

        This method fails to save the batch if the size of an individual object in the batch exceeds 400 KB. For more information on batch restrictions see, http://docs.aws.amazon .com/amazondynamodb/latest/APIReference/API_BatchWriteItem.html

        Specified by:
        batchSave in interface IDynamoDBMapper
        See Also:
        DynamoDBMapper.batchWrite(Iterable, Iterable)

      • batchWrite

        public List<DynamoDBMapper.FailedBatch> batchWrite​(Iterable<? extends Object> objectsToWrite,
                                                   Iterable<? extends Object> objectsToDelete)
        Description copied from interface: IDynamoDBMapper
        Saves and deletes the objects given using one or more calls to the AmazonDynamoDB.batchWriteItem(BatchWriteItemRequest) API. No version checks are performed, as required by the API.

        This method ignores any SaveBehavior set on the mapper, and always behaves as if SaveBehavior.CLOBBER was specified, as the AmazonDynamoDB.batchWriteItem() request does not support updating existing items.

        This method fails to save the batch if the size of an individual object in the batch exceeds 400 KB. For more information on batch restrictions see, http://docs.aws.amazon .com/amazondynamodb/latest/APIReference/API_BatchWriteItem.html

        If one of the write requests is for a table that is not present, this method does not throw a ResourceNotFoundException but returns a FailedBatch which includes this exception and the unprocessed items.

        Specified by:
        batchWrite in interface IDynamoDBMapper
        See Also:
        DynamoDBMapper.batchWrite(Iterable, Iterable)

      • batchLoad

        public Map<String,​List<Object>> batchLoad​(Iterable<? extends Object> itemsToGet)
        Description copied from interface: IDynamoDBMapper
        Retrieves multiple items from multiple tables using their primary keys.
        Specified by:
        batchLoad in interface IDynamoDBMapper
        Returns:
        A map of the loaded objects. Each key in the map is the name of a DynamoDB table. Each value in the map is a list of objects that have been loaded from that table. All objects for each table can be cast to the associated user defined type that is annotated as mapping that table.
        See Also:
        DynamoDBMapper#batchLoad(List, DynamoDBMapperConfig)

      • batchLoad

        public Map<String,​List<Object>> batchLoad​(Map<Class<?>,​List<KeyPair>> itemsToGet,
                                                DynamoDBMapperConfig config)
        Description copied from interface: IDynamoDBMapper
        Retrieves multiple items from multiple tables using their primary keys. Valid only for tables with a single hash key, or a single hash and range key. For other schemas, use DynamoDBMapper#batchLoad(List, DynamoDBMapperConfig)
        Specified by:
        batchLoad in interface IDynamoDBMapper
        Parameters:
        itemsToGet - Map from class to load to list of primary key attributes.
        config - Only DynamoDBMapperConfig.getTableNameOverride() and DynamoDBMapperConfig.getConsistentReads() are considered.
        Returns:
        A map of the loaded objects. Each key in the map is the name of a DynamoDB table. Each value in the map is a list of objects that have been loaded from that table. All objects for each table can be cast to the associated user defined type that is annotated as mapping that table.

      • scan

        public <T> PaginatedScanList<T> scan​(Class<T> clazz,
                                     DynamoDBScanExpression scanExpression,
                                     DynamoDBMapperConfig config)
        Description copied from interface: IDynamoDBMapper
        Scans through an Amazon DynamoDB table and returns the matching results as an unmodifiable list of instantiated objects. The table to scan is determined by looking at the annotations on the specified class, which declares where to store the object data in Amazon DynamoDB, and the scan expression parameter allows the caller to filter results and control how the scan is executed.

        Callers should be aware that the returned list is unmodifiable, and any attempts to modify the list will result in an UnsupportedOperationException.

        You can specify the pagination loading strategy for this scan operation. By default, the list returned is lazily loaded when possible.

        Specified by:
        scan in interface IDynamoDBMapper
        Type Parameters:
        T - The type of the objects being returned.
        Parameters:
        clazz - The class annotated with DynamoDB annotations describing how to store the object data in Amazon DynamoDB.
        scanExpression - Details on how to run the scan, including any filters to apply to limit results.
        config - The configuration to use for this scan, which overrides the default provided at object construction.
        Returns:
        An unmodifiable list of the objects constructed from the results of the scan operation.
        See Also:
        PaginatedScanList, DynamoDBMapperConfig.PaginationLoadingStrategy

      • parallelScan

        public <T> PaginatedParallelScanList<T> parallelScan​(Class<T> clazz,
                                                     DynamoDBScanExpression scanExpression,
                                                     int totalSegments,
                                                     DynamoDBMapperConfig config)
        Description copied from interface: IDynamoDBMapper
        Scans through an Amazon DynamoDB table on logically partitioned segments in parallel. This method will create a thread pool of the specified size, and each thread will issue scan requests for its assigned segment, following the returned continuation token, until the end of its segment. Callers should be responsible for setting the appropriate number of total segments. More scan segments would result in better performance but more consumed capacity of the table. The results are returned in one unmodifiable list of instantiated objects. The table to scan is determined by looking at the annotations on the specified class, which declares where to store the object data in Amazon DynamoDB, and the scan expression parameter allows the caller to filter results and control how the scan is executed.

        Callers should be aware that the returned list is unmodifiable, and any attempts to modify the list will result in an UnsupportedOperationException.

        You can specify the pagination loading strategy for this parallel scan operation. By default, the list returned is lazily loaded when possible.

        Specified by:
        parallelScan in interface IDynamoDBMapper
        Type Parameters:
        T - The type of the objects being returned.
        Parameters:
        clazz - The class annotated with DynamoDB annotations describing how to store the object data in Amazon DynamoDB.
        scanExpression - Details on how to run the scan, including any filters to apply to limit results.
        totalSegments - Number of total parallel scan segments. Range: 1 - 4096
        config - The configuration to use for this scan, which overrides the default provided at object construction.
        Returns:
        An unmodifiable list of the objects constructed from the results of the scan operation.
        See Also:
        PaginatedParallelScanList, DynamoDBMapperConfig.PaginationLoadingStrategy

      • scanPage

        public <T> ScanResultPage<T> scanPage​(Class<T> clazz,
                                      DynamoDBScanExpression scanExpression,
                                      DynamoDBMapperConfig config)
        Description copied from interface: IDynamoDBMapper
        Scans through an Amazon DynamoDB table and returns a single page of matching results. The table to scan is determined by looking at the annotations on the specified class, which declares where to store the object data in AWS DynamoDB, and the scan expression parameter allows the caller to filter results and control how the scan is executed.
        Specified by:
        scanPage in interface IDynamoDBMapper
        Type Parameters:
        T - The type of the objects being returned.
        Parameters:
        clazz - The class annotated with DynamoDB annotations describing how to store the object data in Amazon DynamoDB.
        scanExpression - Details on how to run the scan, including any filters to apply to limit results.
        config - The configuration to use for this scan, which overrides the default provided at object construction.

      • query

        public <T> PaginatedQueryList<T> query​(Class<T> clazz,
                                       DynamoDBQueryExpression<T> queryExpression,
                                       DynamoDBMapperConfig config)
        Description copied from interface: IDynamoDBMapper
        Queries an Amazon DynamoDB table and returns the matching results as an unmodifiable list of instantiated objects. The table to query is determined by looking at the annotations on the specified class, which declares where to store the object data in Amazon DynamoDB, and the query expression parameter allows the caller to filter results and control how the query is executed.

        When the query is on any local/global secondary index, callers should be aware that the returned object(s) will only contain item attributes that are projected into the index. All the other unprojected attributes will be saved as type default values.

        Callers should also be aware that the returned list is unmodifiable, and any attempts to modify the list will result in an UnsupportedOperationException.

        You can specify the pagination loading strategy for this query operation. By default, the list returned is lazily loaded when possible.

        Specified by:
        query in interface IDynamoDBMapper
        Type Parameters:
        T - The type of the objects being returned.
        Parameters:
        clazz - The class annotated with DynamoDB annotations describing how to store the object data in Amazon DynamoDB.
        queryExpression - Details on how to run the query, including any conditions on the key values
        config - The configuration to use for this query, which overrides the default provided at object construction.
        Returns:
        An unmodifiable list of the objects constructed from the results of the query operation.
        See Also:
        PaginatedQueryList, DynamoDBMapperConfig.PaginationLoadingStrategy

      • queryPage

        public <T> QueryResultPage<T> queryPage​(Class<T> clazz,
                                        DynamoDBQueryExpression<T> queryExpression,
                                        DynamoDBMapperConfig config)
        Description copied from interface: IDynamoDBMapper
        Queries an Amazon DynamoDB table and returns a single page of matching results. The table to query is determined by looking at the annotations on the specified class, which declares where to store the object data in Amazon DynamoDB, and the query expression parameter allows the caller to filter results and control how the query is executed.
        Specified by:
        queryPage in interface IDynamoDBMapper
        Type Parameters:
        T - The type of the objects being returned.
        Parameters:
        clazz - The class annotated with DynamoDB annotations describing how to store the object data in AWS DynamoDB.
        queryExpression - Details on how to run the query, including any conditions on the key values
        config - The configuration to use for this query, which overrides the default provided at object construction.

      • count

        public int count​(Class<?> clazz,
                 DynamoDBScanExpression scanExpression,
                 DynamoDBMapperConfig config)
        Description copied from interface: IDynamoDBMapper
        Evaluates the specified scan expression and returns the count of matching items, without returning any of the actual item data.

        This operation will scan your entire table, and can therefore be very expensive. Use with caution.

        Specified by:
        count in interface IDynamoDBMapper
        Parameters:
        clazz - The class mapped to a DynamoDB table.
        scanExpression - The parameters for running the scan.
        config - The configuration to use for this scan, which overrides the default provided at object construction.
        Returns:
        The count of matching items, without returning any of the actual item data.

      • count

        public <T> int count​(Class<T> clazz,
                     DynamoDBQueryExpression<T> queryExpression,
                     DynamoDBMapperConfig config)
        Description copied from interface: IDynamoDBMapper
        Evaluates the specified query expression and returns the count of matching items, without returning any of the actual item data.
        Specified by:
        count in interface IDynamoDBMapper
        Parameters:
        clazz - The class mapped to a DynamoDB table.
        queryExpression - The parameters for running the scan.
        config - The mapper configuration to use for the query, which overrides the default provided at object construction.
        Returns:
        The count of matching items, without returning any of the actual item data.

      • createS3Link

        public S3Link createS3Link​(String bucketName,
                           String key)
        Description copied from interface: IDynamoDBMapper
        Creates an S3Link with the specified bucket name and key using the default S3 region. This method requires the mapper to have been initialized with the necessary credentials for accessing S3.
        Specified by:
        createS3Link in interface IDynamoDBMapper

      • createS3Link

        public S3Link createS3Link​(Region s3region,
                           String bucketName,
                           String key)
        Description copied from interface: IDynamoDBMapper
        Creates an S3Link with the specified region, bucket name and key. This method requires the mapper to have been initialized with the necessary credentials for accessing S3.
        Specified by:
        createS3Link in interface IDynamoDBMapper

      • generateCreateTableRequest

        public CreateTableRequest generateCreateTableRequest​(Class<?> clazz)
        Description copied from interface: IDynamoDBMapper
        Parse the given POJO class and return the CreateTableRequest for the DynamoDB table it represents. Note that the returned request does not include the required ProvisionedThroughput parameters for the primary table and the GSIs, and that all secondary indexes are initialized with the default projection type - KEY_ONLY.
        Specified by:
        generateCreateTableRequest in interface IDynamoDBMapper