org.springframework.data.util.CustomCollections Maven / Gradle / Ivy
/*
* Copyright 2022-2024 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* https://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License 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 org.springframework.data.util;
import io.vavr.collection.HashMap;
import io.vavr.collection.LinkedHashMap;
import io.vavr.collection.LinkedHashSet;
import io.vavr.collection.Seq;
import io.vavr.collection.Traversable;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.function.BiPredicate;
import java.util.function.Function;
import java.util.function.Supplier;
import java.util.stream.Collectors;
import org.eclipse.collections.api.RichIterable;
import org.eclipse.collections.api.bag.ImmutableBag;
import org.eclipse.collections.api.bag.MutableBag;
import org.eclipse.collections.api.factory.Bags;
import org.eclipse.collections.api.factory.Lists;
import org.eclipse.collections.api.factory.Maps;
import org.eclipse.collections.api.factory.Sets;
import org.eclipse.collections.api.list.ImmutableList;
import org.eclipse.collections.api.list.MutableList;
import org.eclipse.collections.api.map.ImmutableMap;
import org.eclipse.collections.api.map.MapIterable;
import org.eclipse.collections.api.map.MutableMap;
import org.eclipse.collections.api.set.ImmutableSet;
import org.eclipse.collections.api.set.MutableSet;
import org.springframework.core.convert.TypeDescriptor;
import org.springframework.core.convert.converter.ConditionalConverter;
import org.springframework.core.convert.converter.ConditionalGenericConverter;
import org.springframework.core.convert.converter.Converter;
import org.springframework.core.convert.converter.ConverterRegistry;
import org.springframework.core.io.support.SpringFactoriesLoader;
import org.springframework.lang.NonNull;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
/**
* Central API to expose information about custom collections present for Spring Data. Exposes custom collection and map
* types and registers converters to convert them from and to Java-native collections.
*
* @author Oliver Drotbohm
* @since 2.7
* @soundtrack Black Sea Dahu - White Creatures (White Creatures)
*/
public class CustomCollections {
private static final Set> CUSTOM_TYPES, CUSTOM_MAP_TYPES, CUSTOM_COLLECTION_TYPES, PAGINATION_RETURN_TYPES;
private static final Set> COLLECTIONS_AND_MAP = Set.of(Collection.class, List.class, Set.class, Map.class);
private static final SearchableTypes MAP_TYPES, COLLECTION_TYPES;
private static final Collection REGISTRARS;
static {
CUSTOM_TYPES = new HashSet<>();
PAGINATION_RETURN_TYPES = new HashSet<>();
CUSTOM_MAP_TYPES = new HashSet<>();
CUSTOM_COLLECTION_TYPES = new HashSet<>();
REGISTRARS = SpringFactoriesLoader
.loadFactories(CustomCollectionRegistrar.class, CustomCollections.class.getClassLoader())
.stream()
.filter(CustomCollectionRegistrar::isAvailable)
.toList();
REGISTRARS.forEach(it -> {
it.getCollectionTypes().forEach(CustomCollections::registerCollectionType);
it.getMapTypes().forEach(CustomCollections::registerMapType);
it.getAllowedPaginationReturnTypes().forEach(PAGINATION_RETURN_TYPES::add);
});
MAP_TYPES = new SearchableTypes(CUSTOM_MAP_TYPES, Map.class);
COLLECTION_TYPES = new SearchableTypes(CUSTOM_COLLECTION_TYPES, Collection.class);
}
/**
* Returns all custom collection and map types.
*
* @return will never be {@literal null}.
*/
public static Set> getCustomTypes() {
return CUSTOM_TYPES;
}
/**
* Returns all types that are allowed pagination return types.
*
* @return will never be {@literal null}.
*/
public static Set> getPaginationReturnTypes() {
return PAGINATION_RETURN_TYPES;
}
/**
* Returns whether the given type is a map base type.
*
* @param type must not be {@literal null}.
* @return will never be {@literal null}.
*/
public static boolean isMapBaseType(Class type) {
Assert.notNull(type, "Type must not be null");
return MAP_TYPES.has(type);
}
/**
* Returns the map base type for the given type, i.e. the one that's considered the logical map interface ({@link Map}
* for {@link HashMap} etc.).
*
* @param type must not be {@literal null}.
* @return will never be {@literal null}.
* @throws IllegalArgumentException in case we do not find a map base type for the given one.
*/
public static Class getMapBaseType(Class type) throws IllegalArgumentException {
return MAP_TYPES.getSuperType(type);
}
/**
* Returns whether the given type is considered a {@link Map} type.
*
* @param type must not be {@literal null}.
* @return will never be {@literal null}.
*/
public static boolean isMap(Class type) {
return MAP_TYPES.hasSuperTypeFor(type);
}
/**
* Returns whether the given type is considered a {@link Collection} type.
*
* @param type must not be {@literal null}.
* @return will never be {@literal null}.
*/
public static boolean isCollection(Class type) {
return COLLECTION_TYPES.hasSuperTypeFor(type);
}
/**
* Returns all unwrapper functions that transform the custom collections into Java-native ones.
*
* @return will never be {@literal null}.
*/
public static Set> getUnwrappers() {
return REGISTRARS.stream()
.map(CustomCollectionRegistrar::toJavaNativeCollection)
.collect(Collectors.toUnmodifiableSet());
}
/**
* Registers all converters to transform Java-native collections into custom ones and back in the given
* {@link ConverterRegistry}.
*
* @param registry must not be {@literal null}.
*/
public static void registerConvertersIn(ConverterRegistry registry) {
Assert.notNull(registry, "ConverterRegistry must not be null");
REGISTRARS.forEach(it -> it.registerConvertersIn(registry));
}
private static void registerCollectionType(Class type) {
CUSTOM_TYPES.add(type);
CUSTOM_COLLECTION_TYPES.add(type);
}
private static void registerMapType(Class type) {
CUSTOM_TYPES.add(type);
CUSTOM_MAP_TYPES.add(type);
}
private static class SearchableTypes {
private static final BiPredicate, Class> EQUALS = (left, right) -> left.equals(right);
private static final BiPredicate, Class> IS_ASSIGNABLE = (left, right) -> left.isAssignableFrom(right);
private static final Function, Boolean> IS_NOT_NULL = it -> it != null;
private final Collection> types;
public SearchableTypes(Set> types, Class... additional) {
var all = new ArrayList<>(List.of(additional));
all.addAll(types);
this.types = all;
}
public boolean hasSuperTypeFor(Class type) {
Assert.notNull(type, "Type must not be null");
return isOneOf(type, IS_ASSIGNABLE, IS_NOT_NULL);
}
/**
* Returns whether the current's raw type is one of the given ones.
*
* @param type must not be {@literal null}.
* @return
*/
public boolean has(Class type) {
Assert.notNull(type, "Type must not be null");
return isOneOf(type, EQUALS, IS_NOT_NULL);
}
/**
* Returns the super type of the given one from the set of types.
*
* @param type must not be {@literal null}.
* @return will never be {@literal null}.
* @throws IllegalArgumentException in case no base type of the given one can be found.
*/
public Class getSuperType(Class type) {
Assert.notNull(type, "Type must not be null");
Supplier message = () -> String.format("Type %s not contained in candidates %s", type, types);
return isOneOf(type, (l, r) -> l.isAssignableFrom(r), rejectNull(message));
}
/**
* Returns whether the given type matches one of the given candidates given the matcher with the
*
* @param
* @param type the type to match against the current candidates.
* @param matcher how to match the candidates against the given type.
* @param resultMapper a {@link Function} to map the potentially given type to the actual result.
* @return will never be {@literal null}.
*/
private T isOneOf(Class type, BiPredicate, Class> matcher, Function, T> resultMapper) {
for (var candidate : types) {
if (matcher.test(candidate, type)) {
return resultMapper.apply(candidate);
}
}
return resultMapper.apply(null);
}
/**
* Returns a function that rejects the source {@link Class} resolving the given message if the former is
* {@literal null}.
*
* @param message must not be {@literal null}.
* @return will never be {@literal null}.
*/
private static Function, Class> rejectNull(Supplier message) {
Assert.notNull(message, "Message must not be null");
return candidate -> {
if (candidate == null) {
throw new IllegalArgumentException(message.get());
}
return candidate;
};
}
}
static class VavrCollections implements CustomCollectionRegistrar {
private static final TypeDescriptor OBJECT_DESCRIPTOR = TypeDescriptor.valueOf(Object.class);
@Override
public boolean isAvailable() {
return ClassUtils.isPresent("io.vavr.control.Option", VavrCollections.class.getClassLoader());
}
@Override
public Collection> getMapTypes() {
return Set.of(io.vavr.collection.Map.class);
}
@Override
public Collection> getCollectionTypes() {
return List.of(Seq.class, io.vavr.collection.Set.class);
}
@Override
public Collection> getAllowedPaginationReturnTypes() {
return Set.of(Seq.class);
}
@Override
public void registerConvertersIn(ConverterRegistry registry) {
registry.addConverter(JavaToVavrCollectionConverter.INSTANCE);
registry.addConverter(VavrToJavaCollectionConverter.INSTANCE);
}
@Override
@SuppressWarnings("null")
public Function toJavaNativeCollection() {
return source -> source instanceof io.vavr.collection.Traversable
? VavrToJavaCollectionConverter.INSTANCE.convert(source, TypeDescriptor.forObject(source), OBJECT_DESCRIPTOR)
: source;
}
private enum VavrToJavaCollectionConverter implements ConditionalGenericConverter {
INSTANCE;
private static final TypeDescriptor TRAVERSAL_TYPE = TypeDescriptor.valueOf(Traversable.class);
@NonNull
@Override
public Set getConvertibleTypes() {
return COLLECTIONS_AND_MAP.stream()
.map(it -> new ConvertiblePair(Traversable.class, it))
.collect(Collectors.toSet());
}
@Override
public boolean matches(TypeDescriptor sourceType, TypeDescriptor targetType) {
return sourceType.isAssignableTo(TRAVERSAL_TYPE)
&& COLLECTIONS_AND_MAP.contains(targetType.getType());
}
@Nullable
@Override
public Object convert(@Nullable Object source, TypeDescriptor sourceType, TypeDescriptor targetType) {
if (source == null) {
return null;
}
if (source instanceof io.vavr.collection.Seq) {
return ((io.vavr.collection.Seq) source).asJava();
}
if (source instanceof io.vavr.collection.Map) {
return ((io.vavr.collection.Map) source).toJavaMap();
}
if (source instanceof io.vavr.collection.Set) {
return ((io.vavr.collection.Set) source).toJavaSet();
}
throw new IllegalArgumentException("Unsupported Vavr collection " + source.getClass());
}
}
private enum JavaToVavrCollectionConverter implements ConditionalGenericConverter {
INSTANCE;
private static final Set CONVERTIBLE_PAIRS;
static {
Set pairs = new HashSet<>();
pairs.add(new ConvertiblePair(Collection.class, io.vavr.collection.Traversable.class));
pairs.add(new ConvertiblePair(Map.class, io.vavr.collection.Traversable.class));
CONVERTIBLE_PAIRS = Collections.unmodifiableSet(pairs);
}
@NonNull
@Override
public java.util.Set getConvertibleTypes() {
return CONVERTIBLE_PAIRS;
}
@Override
public boolean matches(TypeDescriptor sourceType, TypeDescriptor targetType) {
// Prevent collections to be mapped to maps
if (sourceType.isCollection() && io.vavr.collection.Map.class.isAssignableFrom(targetType.getType())) {
return false;
}
// Prevent maps to be mapped to collections
if (sourceType.isMap() && !(io.vavr.collection.Map.class.isAssignableFrom(targetType.getType())
|| targetType.getType().equals(Traversable.class))) {
return false;
}
return true;
}
@Nullable
@Override
public Object convert(@Nullable Object source, TypeDescriptor sourceDescriptor, TypeDescriptor targetDescriptor) {
var targetType = targetDescriptor.getType();
if (io.vavr.collection.Seq.class.isAssignableFrom(targetType)) {
return io.vavr.collection.List.ofAll((Iterable) source);
}
if (io.vavr.collection.Set.class.isAssignableFrom(targetType)) {
return LinkedHashSet.ofAll((Iterable) source);
}
if (io.vavr.collection.Map.class.isAssignableFrom(targetType)) {
return LinkedHashMap.ofAll((Map) source);
}
// No dedicated type asked for, probably Traversable.
// Try to stay as close to the source value.
if (source instanceof List) {
return io.vavr.collection.List.ofAll((Iterable) source);
}
if (source instanceof Set) {
return LinkedHashSet.ofAll((Iterable) source);
}
if (source instanceof Map) {
return LinkedHashMap.ofAll((Map) source);
}
return source;
}
}
}
static class EclipseCollections implements CustomCollectionRegistrar {
@Override
public boolean isAvailable() {
return ClassUtils.isPresent("org.eclipse.collections.api.list.ImmutableList",
EclipseCollections.class.getClassLoader());
}
@Override
public Collection> getCollectionTypes() {
return List.of(ImmutableList.class, ImmutableSet.class, ImmutableBag.class, MutableList.class, MutableSet.class,
MutableBag.class);
}
@Override
public Collection> getMapTypes() {
return List.of(ImmutableMap.class, MutableMap.class);
}
@Override
public Collection> getAllowedPaginationReturnTypes() {
return List.of(ImmutableList.class, MutableList.class);
}
@Override
public Function toJavaNativeCollection() {
return source -> source instanceof RichIterable
? EclipseToJavaConverter.INSTANCE.convert(source)
: source;
}
@Override
public void registerConvertersIn(ConverterRegistry registry) {
registry.addConverter(EclipseToJavaConverter.INSTANCE);
registry.addConverter(JavaToEclipseConverter.INSTANCE);
}
enum EclipseToJavaConverter implements Converter, ConditionalConverter {
INSTANCE;
private static final TypeDescriptor RICH_ITERABLE_DESCRIPTOR = TypeDescriptor.valueOf(RichIterable.class);
@Override
public boolean matches(TypeDescriptor sourceType, TypeDescriptor targetType) {
return sourceType.isAssignableTo(RICH_ITERABLE_DESCRIPTOR)
&& COLLECTIONS_AND_MAP.contains(targetType.getType());
}
@Nullable
@Override
public Object convert(@Nullable Object source) {
if (source instanceof ImmutableList) {
return ((ImmutableList) source).toList();
}
if (source instanceof ImmutableBag) {
return ((ImmutableBag) source).toList();
}
if (source instanceof ImmutableSet) {
return ((ImmutableSet) source).toSet();
}
if (source instanceof ImmutableMap) {
return ((ImmutableMap) source).toMap();
}
return source;
}
}
enum JavaToEclipseConverter implements ConditionalGenericConverter {
INSTANCE;
private static final Set CONVERTIBLE_PAIRS;
static {
var pairs = new HashSet();
pairs.add(new ConvertiblePair(Collection.class, RichIterable.class));
pairs.add(new ConvertiblePair(Set.class, MutableSet.class));
pairs.add(new ConvertiblePair(Set.class, MutableList.class));
pairs.add(new ConvertiblePair(Set.class, ImmutableSet.class));
pairs.add(new ConvertiblePair(Set.class, ImmutableList.class));
pairs.add(new ConvertiblePair(List.class, MutableList.class));
pairs.add(new ConvertiblePair(List.class, ImmutableList.class));
pairs.add(new ConvertiblePair(Map.class, RichIterable.class));
pairs.add(new ConvertiblePair(Map.class, MutableMap.class));
pairs.add(new ConvertiblePair(Map.class, ImmutableMap.class));
CONVERTIBLE_PAIRS = Collections.unmodifiableSet(pairs);
}
@NonNull
@Override
public Set getConvertibleTypes() {
return CONVERTIBLE_PAIRS;
}
@Override
public boolean matches(TypeDescriptor sourceType, TypeDescriptor targetType) {
// Prevent collections to be mapped to maps
if (sourceType.isCollection() && MapIterable.class.isAssignableFrom(targetType.getType())) {
return false;
}
// Prevent maps to be mapped to collections
if (sourceType.isMap() //
&& !(MapIterable.class.isAssignableFrom(targetType.getType())
|| targetType.getType().equals(RichIterable.class))) {
return false;
}
return true;
}
@Nullable
@Override
public Object convert(@Nullable Object source, TypeDescriptor sourceDescriptor, TypeDescriptor targetDescriptor) {
var targetType = targetDescriptor.getType();
if (ImmutableList.class.isAssignableFrom(targetType)) {
return Lists.immutable.ofAll((Iterable) source);
}
if (ImmutableSet.class.isAssignableFrom(targetType)) {
return Sets.immutable.ofAll((Iterable) source);
}
if (ImmutableBag.class.isAssignableFrom(targetType)) {
return Bags.immutable.ofAll((Iterable) source);
}
if (ImmutableMap.class.isAssignableFrom(targetType)) {
return Maps.immutable.ofAll((Map) source);
}
if (MutableList.class.isAssignableFrom(targetType)) {
return Lists.mutable.ofAll((Iterable) source);
}
if (MutableSet.class.isAssignableFrom(targetType)) {
return Sets.mutable.ofAll((Iterable) source);
}
if (MutableBag.class.isAssignableFrom(targetType)) {
return Bags.mutable.ofAll((Iterable) source);
}
if (MutableMap.class.isAssignableFrom(targetType)) {
return Maps.mutable.ofMap((Map) source);
}
// No dedicated type asked for, probably RichIterable.
// Try to stay as close to the source value.
if (source instanceof List) {
return Lists.mutable.ofAll((Iterable) source);
}
if (source instanceof Set) {
return Sets.mutable.ofAll((Iterable) source);
}
if (source instanceof Map) {
return Maps.mutable.ofMap((Map) source);
}
return source;
}
}
}
}
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