software.amazon.awssdk.extensions.dynamodb.mappingclient

Interface TableMetadata

All Known Implementing Classes:

StaticTableMetadata

public interface TableMetadata

Interface for an object the stores structural information about a DynamoDb table.

Method Summary

Modifier and Type	Method and Description
Collection<String>	allKeys() Returns all the names of attributes associated with any index (primary or secondary) known for this table.
<T> Optional<T>	customMetadataObject(String key, Class<? extends T> objectClass) Returns a custom metadata object.
Collection<String>	indexKeys(String indexName) Returns all the names of attributes associated with the keys of a specified index.
String	indexPartitionKey(String indexName) Returns the attribute name of the partition key for an index.
Optional<String>	indexSortKey(String indexName) Returns the attribute name of the sort key for an index.
static String	primaryIndexName() Returns an arbitrary constant that should be used as the primary index name.
default Collection<String>	primaryKeys() Returns the names of the attributes that make up the primary key for the table.
default String	primaryPartitionKey() Returns the attribute name used as the primary partition key for the table.
default Optional<String>	primarySortKey() Returns the attribute name used as the primary sort key for the table.
Optional<ScalarAttributeType>	scalarAttributeType(String keyAttribute) Returns the DynamoDb scalar attribute type associated with a key attribute if one is applicable.

Method Detail

indexPartitionKey

String indexPartitionKey(String indexName)

Returns the attribute name of the partition key for an index.

Parameters:

indexName - The name of the index.

Returns:

The attribute name representing the partition key for this index.

Throws:

IllegalArgumentException - if the index does not exist in the metadata or does not have a partition key associated with it..

indexSortKey

Optional<String> indexSortKey(String indexName)

Returns the attribute name of the sort key for an index.

Parameters:

indexName - The name of the index.

Returns:

Optional of the attribute name representing the sort key for this index; empty if the index does not have a sort key.

customMetadataObject

<T> Optional<T> customMetadataObject(String key,
                                     Class<? extends T> objectClass)

Returns a custom metadata object. These objects are used by extensions to the library, therefore the type of object stored is flexible and does not need to be known by the interface.

Type Parameters:

T - The flexible type for the object being returned. The compiler will typically infer this.

Parameters:

key - A unique key for the metadata object. This namespace is shared by all extensions, so it is recommended best practice to qualify it with the name of your extension.

objectClass - The java class that the object will be cast to before returning. An exception will be thrown if the stored object cannot be cast to this class.

Returns:

An optional containing custom metadata object or empty if the object was not found.

indexKeys

Collection<String> indexKeys(String indexName)

Returns all the names of attributes associated with the keys of a specified index.

Parameters:

indexName - The name of the index.

Returns:

A collection of all key attribute names for that index.

allKeys

Collection<String> allKeys()

Returns all the names of attributes associated with any index (primary or secondary) known for this table. Additionally any additional attributes that are deemed to be 'key-like' in how they should be treated will also be returned. An example of a 'key-like' attribute that is not actually a key is one tagged as a 'version' attribute when using the versioned record extension.

Returns:

A collection of all key attribute names for the table.

scalarAttributeType

Optional<ScalarAttributeType> scalarAttributeType(String keyAttribute)

Returns the DynamoDb scalar attribute type associated with a key attribute if one is applicable.

Parameters:

keyAttribute - The key attribute name to return the scalar attribute type of.

Returns:

Optional ScalarAttributeType of the attribute, or empty if attribute is a non-scalar type.

Throws:

IllegalArgumentException - if the keyAttribute is not found.

primaryPartitionKey

default String primaryPartitionKey()

Returns the attribute name used as the primary partition key for the table.

Returns:

The primary partition key attribute name.

Throws:

IllegalArgumentException - if the primary partition key is not known.

primarySortKey

default Optional<String> primarySortKey()

Returns the attribute name used as the primary sort key for the table.

Returns:

An optional of the primary sort key attribute name; empty if this key is not known.

primaryKeys

default Collection<String> primaryKeys()

Returns the names of the attributes that make up the primary key for the table.

Returns:

A collection of attribute names that make up the primary key for the table.

primaryIndexName

static String primaryIndexName()

Returns an arbitrary constant that should be used as the primary index name. This pattern creates a common abstraction and simplifies the implementation of operations that also work on secondary indices such as scan() and query().

Returns:

An arbitrary constant that internally represents the primary index name.