Class MapAttributeConverter<T extends Map<?,?>>

java.lang.Object

software.amazon.awssdk.enhanced.dynamodb.internal.converter.attribute.MapAttributeConverter<T>

All Implemented Interfaces:

AttributeConverter<T>

@ThreadSafe
@Immutable
public class MapAttributeConverter<T extends Map<?,?>>
extends Object
implements AttributeConverter<T>

A converter between a specific Map type and AttributeValue.

This stores values in DynamoDB as a map from string to attribute value. This uses a configured StringAttributeConverter to convert the map keys to a string, and a configured AttributeConverter to convert the map values to an attribute value.

This supports reading maps from DynamoDB. This uses a configured StringAttributeConverter to convert the map keys, and a configured AttributeConverter to convert the map values.

A builder is exposed to allow defining how the map, key and value types are created and converted:

AttributeConverter<Map<MonthDay, String>> mapConverter = MapAttributeConverter.builder(EnhancedType.mapOf(Integer.class, String.class)) .mapConstructor(HashMap::new) .keyConverter(MonthDayStringConverter.create()) .valueConverter(StringAttributeConverter.create()) .build();

For frequently-used types, static methods are exposed to reduce the amount of boilerplate involved in creation: AttributeConverter<Map<MonthDay, String>> mapConverter = MapAttributeConverter.mapConverter(MonthDayStringConverter.create(), StringAttributeConverter.create());

AttributeConverter<SortedMap<MonthDay, String>> sortedMapConverter = MapAttributeConverter.sortedMapConverter(MonthDayStringConverter.create(), StringAttributeConverter.create());

See Also:

• MapAttributeConverter

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static final class	MapAttributeConverter.Builder<T extends Map<K,V>,K,V>

Method Summary

Modifier and Type	Method	Description
AttributeValueType	attributeValueType()	The AttributeValueType that a converter stores and reads values from DynamoDB via the AttributeValue class.
static <T extends Map<K, V>, K, V> MapAttributeConverter.Builder<T,K,V>	builder(EnhancedType<T> mapType)
static <K, V> MapAttributeConverter<ConcurrentMap<K,V>>	concurrentMapConverter(StringConverter<K> keyConverter, AttributeConverter<V> valueConverter)
static <K, V> MapAttributeConverter<Map<K,V>>	mapConverter(StringConverter<K> keyConverter, AttributeConverter<V> valueConverter)
static <K, V> MapAttributeConverter<NavigableMap<K,V>>	navigableMapConverter(StringConverter<K> keyConverter, AttributeConverter<V> valueConverter)
static <K, V> MapAttributeConverter<SortedMap<K,V>>	sortedMapConverter(StringConverter<K> keyConverter, AttributeConverter<V> valueConverter)
AttributeValue	transformFrom(T input)	Convert the provided Java object into an AttributeValue.
T	transformTo(AttributeValue input)	Convert the provided AttributeValue into a Java object.
EnhancedType<T>	type()	The type supported by this converter.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

mapConverter

public static <K,
V>
MapAttributeConverter<Map<K,V>> mapConverter(StringConverter<K> keyConverter,
 AttributeConverter<V> valueConverter)

concurrentMapConverter

public static <K,
V>
MapAttributeConverter<ConcurrentMap<K,V>> concurrentMapConverter(StringConverter<K> keyConverter,
 AttributeConverter<V> valueConverter)

sortedMapConverter

public static <K,
V>
MapAttributeConverter<SortedMap<K,V>> sortedMapConverter(StringConverter<K> keyConverter,
 AttributeConverter<V> valueConverter)

navigableMapConverter

public static <K,
V>
MapAttributeConverter<NavigableMap<K,V>> navigableMapConverter(StringConverter<K> keyConverter,
 AttributeConverter<V> valueConverter)

builder

public static <T extends Map<K,
V>,
K,
V>
MapAttributeConverter.Builder<T,K,V> builder(EnhancedType<T> mapType)

type

public EnhancedType<T> type()

Description copied from interface: AttributeConverter

The type supported by this converter.

Specified by:

type in interface AttributeConverter<T extends Map<?,?>>

attributeValueType

public AttributeValueType attributeValueType()

Description copied from interface: AttributeConverter

The AttributeValueType that a converter stores and reads values from DynamoDB via the AttributeValue class.

Specified by:

attributeValueType in interface AttributeConverter<T extends Map<?,?>>

transformFrom

public AttributeValue transformFrom(T input)

Description copied from interface: AttributeConverter

Convert the provided Java object into an AttributeValue. This will raise a RuntimeException if the conversion fails, or the input is null.

Example:

 
 InstantAsStringAttributeConverter converter = InstantAsStringAttributeConverter.create();
 assertEquals(converter.transformFrom(Instant.EPOCH),
              EnhancedAttributeValue.fromString("1970-01-01T00:00:00Z").toAttributeValue());
 
 

Specified by:

transformFrom in interface AttributeConverter<T extends Map<?,?>>

transformTo

public T transformTo(AttributeValue input)

Description copied from interface: AttributeConverter

Convert the provided AttributeValue into a Java object. This will raise a RuntimeException if the conversion fails, or the input is null.

 Example:
 
 InstantAsStringAttributeConverter converter = InstantAsStringAttributeConverter.create();
 assertEquals(converter.transformTo(EnhancedAttributeValue.fromString("1970-01-01T00:00:00Z").toAttributeValue()),
              Instant.EPOCH);
 
 

Specified by:

transformTo in interface AttributeConverter<T extends Map<?,?>>