software.amazon.awssdk.enhanced.dynamodb.mapper.StaticImmutableTableSchema Maven / Gradle / Ivy
/*
* Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License").
* You may not use this file except in compliance with the License.
* A copy of the License is located at
*
* http://aws.amazon.com/apache2.0
*
* or in the "license" file accompanying this file. This file is distributed
* on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
* express or implied. See the License for the specific language governing
* permissions and limitations under the License.
*/
package software.amazon.awssdk.enhanced.dynamodb.mapper;
import static java.util.Collections.unmodifiableMap;
import static software.amazon.awssdk.enhanced.dynamodb.internal.EnhancedClientUtils.isNullAttributeValue;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.function.BiConsumer;
import java.util.function.Consumer;
import java.util.function.Function;
import java.util.function.Supplier;
import java.util.stream.Stream;
import software.amazon.awssdk.annotations.NotThreadSafe;
import software.amazon.awssdk.annotations.SdkPublicApi;
import software.amazon.awssdk.annotations.ThreadSafe;
import software.amazon.awssdk.enhanced.dynamodb.AttributeConverter;
import software.amazon.awssdk.enhanced.dynamodb.AttributeConverterProvider;
import software.amazon.awssdk.enhanced.dynamodb.DefaultAttributeConverterProvider;
import software.amazon.awssdk.enhanced.dynamodb.EnhancedType;
import software.amazon.awssdk.enhanced.dynamodb.TableSchema;
import software.amazon.awssdk.enhanced.dynamodb.internal.converter.ConverterProviderResolver;
import software.amazon.awssdk.enhanced.dynamodb.internal.mapper.ResolvedImmutableAttribute;
import software.amazon.awssdk.services.dynamodb.model.AttributeValue;
/**
* Implementation of {@link TableSchema} that builds a schema for immutable data objects based on directly declared
* attributes. Just like {@link StaticTableSchema} which is the equivalent implementation for mutable objects, this is
* the most direct, and thus fastest, implementation of {@link TableSchema}.
*
* Example using a fictional 'Customer' immutable data item class that has an inner builder class named 'Builder':-
* {@code
* static final TableSchema CUSTOMER_TABLE_SCHEMA =
* StaticImmutableTableSchema.builder(Customer.class, Customer.Builder.class)
* .newItemBuilder(Customer::builder, Customer.Builder::build)
* .addAttribute(String.class, a -> a.name("account_id")
* .getter(Customer::accountId)
* .setter(Customer.Builder::accountId)
* .tags(primaryPartitionKey()))
* .addAttribute(Integer.class, a -> a.name("sub_id")
* .getter(Customer::subId)
* .setter(Customer.Builder::subId)
* .tags(primarySortKey()))
* .addAttribute(String.class, a -> a.name("name")
* .getter(Customer::name)
* .setter(Customer.Builder::name)
* .tags(secondaryPartitionKey("customers_by_name")))
* .addAttribute(Instant.class, a -> a.name("created_date")
* .getter(Customer::createdDate)
* .setter(Customer.Builder::createdDate)
* .tags(secondarySortKey("customers_by_date"),
* secondarySortKey("customers_by_name")))
* .build();
* }
*/
@SdkPublicApi
@ThreadSafe
public final class StaticImmutableTableSchema implements TableSchema {
private final List> attributeMappers;
private final Supplier newBuilderSupplier;
private final Function buildItemFunction;
private final Map> indexedMappers;
private final StaticTableMetadata tableMetadata;
private final EnhancedType itemType;
private final AttributeConverterProvider attributeConverterProvider;
private final Map> indexedFlattenedMappers;
private final List attributeNames;
private static class FlattenedMapper {
private final Function otherItemGetter;
private final BiConsumer otherItemSetter;
private final TableSchema otherItemTableSchema;
private FlattenedMapper(Function otherItemGetter,
BiConsumer otherItemSetter,
TableSchema otherItemTableSchema) {
this.otherItemGetter = otherItemGetter;
this.otherItemSetter = otherItemSetter;
this.otherItemTableSchema = otherItemTableSchema;
}
public TableSchema getOtherItemTableSchema() {
return otherItemTableSchema;
}
private B mapToItem(B thisBuilder,
Supplier thisBuilderConstructor,
Map attributeValues) {
T1 otherItem = this.otherItemTableSchema.mapToItem(attributeValues);
if (otherItem != null) {
if (thisBuilder == null) {
thisBuilder = thisBuilderConstructor.get();
}
this.otherItemSetter.accept(thisBuilder, otherItem);
}
return thisBuilder;
}
private Map itemToMap(T item, boolean ignoreNulls) {
T1 otherItem = this.otherItemGetter.apply(item);
if (otherItem == null) {
return Collections.emptyMap();
}
return this.otherItemTableSchema.itemToMap(otherItem, ignoreNulls);
}
private AttributeValue attributeValue(T item, String attributeName) {
T1 otherItem = this.otherItemGetter.apply(item);
if (otherItem == null) {
return null;
}
AttributeValue attributeValue = this.otherItemTableSchema.attributeValue(otherItem, attributeName);
return isNullAttributeValue(attributeValue) ? null : attributeValue;
}
}
private StaticImmutableTableSchema(Builder builder) {
StaticTableMetadata.Builder tableMetadataBuilder = StaticTableMetadata.builder();
this.attributeConverterProvider =
ConverterProviderResolver.resolveProviders(builder.attributeConverterProviders);
// Resolve declared attributes and find converters for them
Stream> attributesStream = builder.attributes == null ?
Stream.empty() : builder.attributes.stream().map(a -> a.resolve(this.attributeConverterProvider));
// Merge resolved declared attributes
List> mutableAttributeMappers = new ArrayList<>();
Map> mutableIndexedMappers = new HashMap<>();
Set mutableAttributeNames = new LinkedHashSet<>();
Stream.concat(attributesStream, builder.additionalAttributes.stream()).forEach(
resolvedAttribute -> {
String attributeName = resolvedAttribute.attributeName();
if (mutableAttributeNames.contains(attributeName)) {
throw new IllegalArgumentException(
"Attempt to add an attribute to a mapper that already has one with the same name. " +
"[Attribute name: " + attributeName + "]");
}
mutableAttributeNames.add(attributeName);
mutableAttributeMappers.add(resolvedAttribute);
mutableIndexedMappers.put(attributeName, resolvedAttribute);
// Merge in metadata associated with attribute
tableMetadataBuilder.mergeWith(resolvedAttribute.tableMetadata());
}
);
Map> mutableFlattenedMappers = new HashMap<>();
builder.flattenedMappers.forEach(
flattenedMapper -> {
flattenedMapper.otherItemTableSchema.attributeNames().forEach(
attributeName -> {
if (mutableAttributeNames.contains(attributeName)) {
throw new IllegalArgumentException(
"Attempt to add an attribute to a mapper that already has one with the same name. " +
"[Attribute name: " + attributeName + "]");
}
mutableAttributeNames.add(attributeName);
mutableFlattenedMappers.put(attributeName, flattenedMapper);
}
);
tableMetadataBuilder.mergeWith(flattenedMapper.getOtherItemTableSchema().tableMetadata());
}
);
// Apply table-tags to table metadata
if (builder.tags != null) {
builder.tags.forEach(staticTableTag -> staticTableTag.modifyMetadata().accept(tableMetadataBuilder));
}
this.attributeMappers = Collections.unmodifiableList(mutableAttributeMappers);
this.indexedMappers = Collections.unmodifiableMap(mutableIndexedMappers);
this.attributeNames = Collections.unmodifiableList(new ArrayList<>(mutableAttributeNames));
this.indexedFlattenedMappers = Collections.unmodifiableMap(mutableFlattenedMappers);
this.newBuilderSupplier = builder.newBuilderSupplier;
this.buildItemFunction = builder.buildItemFunction;
this.tableMetadata = tableMetadataBuilder.build();
this.itemType = EnhancedType.of(builder.itemClass);
}
/**
* Creates a builder for a {@link StaticImmutableTableSchema} typed to specific immutable data item class.
* @param itemClass The immutable data item class object that the {@link StaticImmutableTableSchema} is to map to.
* @param builderClass The builder class object that can be used to construct instances of the immutable data item.
* @return A newly initialized builder
*/
public static Builder builder(Class itemClass, Class builderClass) {
return new Builder<>(itemClass, builderClass);
}
/**
* Builder for a {@link StaticImmutableTableSchema}
* @param The immutable data item class object that the {@link StaticImmutableTableSchema} is to map to.
* @param The builder class object that can be used to construct instances of the immutable data item.
*/
@NotThreadSafe
public static final class Builder {
private final Class itemClass;
private final Class builderClass;
private final List> additionalAttributes = new ArrayList<>();
private final List> flattenedMappers = new ArrayList<>();
private List> attributes;
private Supplier newBuilderSupplier;
private Function buildItemFunction;
private List tags;
private List attributeConverterProviders =
Collections.singletonList(ConverterProviderResolver.defaultConverterProvider());
private Builder(Class itemClass, Class builderClass) {
this.itemClass = itemClass;
this.builderClass = builderClass;
}
/**
* Methods used to construct a new instance of the immutable data object.
* @param newBuilderMethod A method to create a new builder for the immutable data object.
* @param buildMethod A method on the builder to build a new instance of the immutable data object.
*/
public Builder newItemBuilder(Supplier newBuilderMethod, Function buildMethod) {
this.newBuilderSupplier = newBuilderMethod;
this.buildItemFunction = buildMethod;
return this;
}
/**
* A list of attributes that can be mapped between the data item object and the database record that are to
* be associated with the schema. Will overwrite any existing attributes.
*/
@SafeVarargs
public final Builder attributes(ImmutableAttribute... immutableAttributes) {
this.attributes = Arrays.asList(immutableAttributes);
return this;
}
/**
* A list of attributes that can be mapped between the data item object and the database record that are to
* be associated with the schema. Will overwrite any existing attributes.
*/
public Builder attributes(Collection> immutableAttributes) {
this.attributes = new ArrayList<>(immutableAttributes);
return this;
}
/**
* Adds a single attribute to the table schema that can be mapped between the data item object and the database
* record.
*/
public Builder addAttribute(EnhancedType attributeType,
Consumer> immutableAttribute) {
ImmutableAttribute.Builder builder =
ImmutableAttribute.builder(itemClass, builderClass, attributeType);
immutableAttribute.accept(builder);
return addAttribute(builder.build());
}
/**
* Adds a single attribute to the table schema that can be mapped between the data item object and the database
* record.
*/
public Builder addAttribute(Class attributeClass,
Consumer> immutableAttribute) {
return addAttribute(EnhancedType.of(attributeClass), immutableAttribute);
}
/**
* Adds a single attribute to the table schema that can be mapped between the data item object and the database
* record.
*/
public Builder addAttribute(ImmutableAttribute immutableAttribute) {
if (this.attributes == null) {
this.attributes = new ArrayList<>();
}
this.attributes.add(immutableAttribute);
return this;
}
/**
* Associate one or more {@link StaticTableTag} with this schema. See documentation on the tags themselves to
* understand what each one does. This method will overwrite any existing table tags.
*/
public Builder tags(StaticTableTag... staticTableTags) {
this.tags = Arrays.asList(staticTableTags);
return this;
}
/**
* Associate one or more {@link StaticTableTag} with this schema. See documentation on the tags themselves to
* understand what each one does. This method will overwrite any existing table tags.
*/
public Builder tags(Collection staticTableTags) {
this.tags = new ArrayList<>(staticTableTags);
return this;
}
/**
* Associates a {@link StaticTableTag} with this schema. See documentation on the tags themselves to understand
* what each one does. This method will add the tag to the list of existing table tags.
*/
public Builder addTag(StaticTableTag staticTableTag) {
if (this.tags == null) {
this.tags = new ArrayList<>();
}
this.tags.add(staticTableTag);
return this;
}
/**
* Flattens all the attributes defined in another {@link TableSchema} into the database record this schema
* maps to. Functions to get and set an object that the flattened schema maps to is required.
*/
public Builder flatten(TableSchema otherTableSchema,
Function otherItemGetter,
BiConsumer otherItemSetter) {
if (otherTableSchema.isAbstract()) {
throw new IllegalArgumentException("Cannot flatten an abstract TableSchema. You must supply a concrete " +
"TableSchema that is able to create items");
}
FlattenedMapper flattenedMapper =
new FlattenedMapper<>(otherItemGetter, otherItemSetter, otherTableSchema);
this.flattenedMappers.add(flattenedMapper);
return this;
}
/**
* Extends the {@link StaticImmutableTableSchema} of a super-class, effectively rolling all the attributes modelled by
* the super-class into the {@link StaticImmutableTableSchema} of the sub-class. The extended immutable table schema
* must be using a builder class that is also a super-class of the builder being used for the current immutable
* table schema.
*/
public Builder extend(StaticImmutableTableSchema superTableSchema) {
Stream> attributeStream =
upcastingTransformForAttributes(superTableSchema.attributeMappers);
attributeStream.forEach(this.additionalAttributes::add);
return this;
}
/**
* Specifies the {@link AttributeConverterProvider}s to use with the table schema.
* The list of attribute converter providers must provide {@link AttributeConverter}s for all types used
* in the schema. The attribute converter providers will be loaded in the strict order they are supplied here.
*
* Calling this method will override the default attribute converter provider
* {@link DefaultAttributeConverterProvider}, which provides standard converters for most primitive
* and common Java types, so that provider must included in the supplied list if it is to be
* used. Providing an empty list here will cause no providers to get loaded.
*
* Adding one custom attribute converter provider and using the default as fallback:
* {@code
* builder.attributeConverterProviders(customAttributeConverter, AttributeConverterProvider.defaultProvider())
* }
*
* @param attributeConverterProviders a list of attribute converter providers to use with the table schema
*/
public Builder attributeConverterProviders(AttributeConverterProvider... attributeConverterProviders) {
this.attributeConverterProviders = Arrays.asList(attributeConverterProviders);
return this;
}
/**
* Specifies the {@link AttributeConverterProvider}s to use with the table schema.
* The list of attribute converter providers must provide {@link AttributeConverter}s for all types used
* in the schema. The attribute converter providers will be loaded in the strict order they are supplied here.
*
* Calling this method will override the default attribute converter provider
* {@link DefaultAttributeConverterProvider}, which provides standard converters
* for most primitive and common Java types, so that provider must included in the supplied list if it is to be
* used. Providing an empty list here will cause no providers to get loaded.
*
* Adding one custom attribute converter provider and using the default as fallback:
* {@code
* List providers = new ArrayList<>(
* customAttributeConverter,
* AttributeConverterProvider.defaultProvider());
* builder.attributeConverterProviders(providers);
* }
*
* @param attributeConverterProviders a list of attribute converter providers to use with the table schema
*/
public Builder attributeConverterProviders(List attributeConverterProviders) {
this.attributeConverterProviders = new ArrayList<>(attributeConverterProviders);
return this;
}
/**
* Builds a {@link StaticImmutableTableSchema} based on the values this builder has been configured with
*/
public StaticImmutableTableSchema build() {
return new StaticImmutableTableSchema<>(this);
}
private static Stream>
upcastingTransformForAttributes(Collection> superAttributes) {
return superAttributes.stream().map(attribute -> attribute.transform(x -> x, x -> x));
}
}
@Override
public StaticTableMetadata tableMetadata() {
return tableMetadata;
}
@Override
public T mapToItem(Map attributeMap, boolean preserveEmptyObject) {
B builder = null;
// Instantiate the builder right now if preserveEmtpyBean is true, otherwise lazily instantiate the builder once
// we have an attribute to write
if (preserveEmptyObject) {
builder = constructNewBuilder();
}
Map, Map> flattenedAttributeValuesMap = new LinkedHashMap<>();
for (Map.Entry entry : attributeMap.entrySet()) {
String key = entry.getKey();
AttributeValue value = entry.getValue();
if (!isNullAttributeValue(value)) {
ResolvedImmutableAttribute attributeMapper = indexedMappers.get(key);
if (attributeMapper != null) {
if (builder == null) {
builder = constructNewBuilder();
}
attributeMapper.updateItemMethod().accept(builder, value);
} else {
FlattenedMapper flattenedMapper = this.indexedFlattenedMappers.get(key);
if (flattenedMapper != null) {
Map flattenedAttributeValues =
flattenedAttributeValuesMap.get(flattenedMapper);
if (flattenedAttributeValues == null) {
flattenedAttributeValues = new HashMap<>();
}
flattenedAttributeValues.put(key, value);
flattenedAttributeValuesMap.put(flattenedMapper, flattenedAttributeValues);
}
}
}
}
for (Map.Entry, Map> entry :
flattenedAttributeValuesMap.entrySet()) {
builder = entry.getKey().mapToItem(builder, this::constructNewBuilder, entry.getValue());
}
return builder == null ? null : buildItemFunction.apply(builder);
}
@Override
public T mapToItem(Map attributeMap) {
return mapToItem(attributeMap, false);
}
@Override
public Map itemToMap(T item, boolean ignoreNulls) {
Map attributeValueMap = new HashMap<>();
attributeMappers.forEach(attributeMapper -> {
String attributeKey = attributeMapper.attributeName();
AttributeValue attributeValue = attributeMapper.attributeGetterMethod().apply(item);
if (!ignoreNulls || !isNullAttributeValue(attributeValue)) {
attributeValueMap.put(attributeKey, attributeValue);
}
});
indexedFlattenedMappers.forEach((name, flattenedMapper) -> {
attributeValueMap.putAll(flattenedMapper.itemToMap(item, ignoreNulls));
});
return unmodifiableMap(attributeValueMap);
}
@Override
public Map itemToMap(T item, Collection attributes) {
Map attributeValueMap = new HashMap<>();
attributes.forEach(key -> {
AttributeValue attributeValue = attributeValue(item, key);
if (attributeValue == null || !isNullAttributeValue(attributeValue)) {
attributeValueMap.put(key, attributeValue);
}
});
return unmodifiableMap(attributeValueMap);
}
@Override
public AttributeValue attributeValue(T item, String key) {
ResolvedImmutableAttribute attributeMapper = indexedMappers.get(key);
if (attributeMapper == null) {
FlattenedMapper flattenedMapper = indexedFlattenedMappers.get(key);
if (flattenedMapper == null) {
throw new IllegalArgumentException(String.format("TableSchema does not know how to retrieve requested "
+ "attribute '%s' from mapped object.", key));
}
return flattenedMapper.attributeValue(item, key);
}
AttributeValue attributeValue = attributeMapper.attributeGetterMethod().apply(item);
return isNullAttributeValue(attributeValue) ? null : attributeValue;
}
@Override
public EnhancedType itemType() {
return this.itemType;
}
@Override
public List attributeNames() {
return this.attributeNames;
}
@Override
public boolean isAbstract() {
return this.buildItemFunction == null;
}
/**
* The table schema {@link AttributeConverterProvider}.
* @see Builder#attributeConverterProvider
*/
public AttributeConverterProvider attributeConverterProvider() {
return this.attributeConverterProvider;
}
private B constructNewBuilder() {
if (newBuilderSupplier == null) {
throw new UnsupportedOperationException("An abstract TableSchema cannot be used to map a database record "
+ "to a concrete object. Add a 'newItemBuilder' to the "
+ "TableSchema to give it the ability to create mapped objects.");
}
return newBuilderSupplier.get();
}
@Override
public AttributeConverter converterForAttribute(Object key) {
ResolvedImmutableAttribute resolvedImmutableAttribute = indexedMappers.get(key);
if (resolvedImmutableAttribute != null) {
return resolvedImmutableAttribute.attributeConverter();
}
// If no resolvedAttribute is found look through flattened attributes
FlattenedMapper flattenedMapper = indexedFlattenedMappers.get(key);
if (flattenedMapper != null) {
return (AttributeConverter) flattenedMapper.getOtherItemTableSchema().converterForAttribute(key);
}
return null;
}
}