I have a type which is extending HashMap<String, String>. As per the documentation here, it is possible to add a custom converter for the type. But it seems not working. The contents of the hashMap doesn't get converted, output looks like below;
"summary": {
"en": null
},
Any idea how to convert Label and its fields along with it's hashmap's contents?
Parent
@DynamoDbBean(converterProviders = {
CustomAttributeConverterProvider.class,
DefaultAttributeConverterProvider.class})
public class Summary extends BaseEntry {
private @Valid Label summary = null;
}
Child
@DynamoDbBean(converterProviders = {
CustomAttributeConverterProvider.class,
DefaultAttributeConverterProvider.class})
public class Label extends HashMap<String, String> {
private @Valid String en = null;
}
HashMapAttributeConverter
public class HashMapAttributeConverter implements AttributeConverter<Map<String, String>> {
private static AttributeConverter<Map<String, String>> mapConverter;
/** Default constructor. */
public HashMapAttributeConverter() {
mapConverter =
MapAttributeConverter.builder(EnhancedType.mapOf(String.class, String.class))
.mapConstructor(HashMap::new)
.keyConverter(StringStringConverter.create())
.valueConverter(StringAttributeConverter.create())
.build();
}
@Override
public AttributeValue transformFrom(Map<String, String> input) {
return mapConverter.transformFrom(input);
}
@Override
public Map<String, String> transformTo(AttributeValue input) {
return mapConverter.transformTo(input);
}
@Override
public EnhancedType<Map<String, String>> type() {
return mapConverter.type();
}
@Override
public AttributeValueType attributeValueType() {
return mapConverter.attributeValueType();
}
}
CustomAttributeConverterProvider
public class CustomAttributeConverterProvider implements AttributeConverterProvider {
private final List<AttributeConverter<?>> customConverters =
Arrays.asList(new HashMapAttributeConverter());
private final Map<EnhancedType<?>, AttributeConverter<?>> customConvertersMap;
private final AttributeConverterProvider defaultProvider =
DefaultAttributeConverterProvider.create();
public CustomAttributeConverterProvider() {
customConvertersMap =
customConverters.stream().collect(Collectors.toMap(AttributeConverter::type, c -> c));
}
@Override
public <T> AttributeConverter<T> converterFor(EnhancedType<T> enhancedType) {
return (AttributeConverter<T>)
customConvertersMap.computeIfAbsent(enhancedType, defaultProvider::converterFor);
}
}