KeyValuePartTreeQuery.java
/*
* Copyright 2014-2024 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.keyvalue.repository.query;
import java.lang.reflect.Constructor;
import org.springframework.beans.BeanUtils;
import org.springframework.data.domain.PageImpl;
import org.springframework.data.domain.Pageable;
import org.springframework.data.domain.Sort;
import org.springframework.data.keyvalue.core.IterableConverter;
import org.springframework.data.keyvalue.core.KeyValueOperations;
import org.springframework.data.keyvalue.core.SpelCriteria;
import org.springframework.data.keyvalue.core.query.KeyValueQuery;
import org.springframework.data.repository.query.ParameterAccessor;
import org.springframework.data.repository.query.ParametersParameterAccessor;
import org.springframework.data.repository.query.QueryMethod;
import org.springframework.data.repository.query.QueryMethodEvaluationContextProvider;
import org.springframework.data.repository.query.RepositoryQuery;
import org.springframework.data.repository.query.ResultProcessor;
import org.springframework.data.repository.query.parser.AbstractQueryCreator;
import org.springframework.data.repository.query.parser.PartTree;
import org.springframework.data.spel.EvaluationContextProvider;
import org.springframework.data.util.Lazy;
import org.springframework.expression.EvaluationContext;
import org.springframework.expression.spel.standard.SpelExpression;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
/**
* {@link RepositoryQuery} implementation deriving queries from {@link PartTree} using a predefined
* {@link AbstractQueryCreator}.
*
* @author Christoph Strobl
* @author Oliver Gierke
* @author Mark Paluch
*/
public class KeyValuePartTreeQuery implements RepositoryQuery {
private final Lazy<PartTree> partTree;
private final QueryMethod queryMethod;
private final KeyValueOperations keyValueOperations;
private final QueryMethodEvaluationContextProvider evaluationContextProvider;
private final QueryCreatorFactory<AbstractQueryCreator<KeyValueQuery<?>, ?>> queryCreatorFactory;
/**
* Creates a new {@link KeyValuePartTreeQuery} for the given {@link QueryMethod}, {@link EvaluationContextProvider},
* {@link KeyValueOperations} and query creator type.
*
* @param queryMethod must not be {@literal null}.
* @param evaluationContextProvider must not be {@literal null}.
* @param keyValueOperations must not be {@literal null}.
* @param queryCreator must not be {@literal null}.
*/
public KeyValuePartTreeQuery(QueryMethod queryMethod, QueryMethodEvaluationContextProvider evaluationContextProvider,
KeyValueOperations keyValueOperations, Class<? extends AbstractQueryCreator<?, ?>> queryCreator) {
this(queryMethod, evaluationContextProvider, keyValueOperations,
new ConstructorCachingQueryCreatorFactory(queryCreator));
}
/**
* Creates a new {@link KeyValuePartTreeQuery} for the given {@link QueryMethod}, {@link EvaluationContextProvider},
* {@link KeyValueOperations} using the given {@link QueryCreatorFactory} producing the {@link AbstractQueryCreator}
* in charge of altering the query.
*
* @param queryMethod must not be {@literal null}.
* @param evaluationContextProvider must not be {@literal null}.
* @param keyValueOperations must not be {@literal null}.
* @param queryCreatorFactory must not be {@literal null}.
* @since 2.0
*/
public KeyValuePartTreeQuery(QueryMethod queryMethod, QueryMethodEvaluationContextProvider evaluationContextProvider,
KeyValueOperations keyValueOperations,
QueryCreatorFactory<AbstractQueryCreator<KeyValueQuery<?>, ?>> queryCreatorFactory) {
Assert.notNull(queryMethod, "Query method must not be null");
Assert.notNull(evaluationContextProvider, "EvaluationContextprovider must not be null");
Assert.notNull(keyValueOperations, "KeyValueOperations must not be null");
Assert.notNull(queryCreatorFactory, "QueryCreatorFactory type must not be null");
this.partTree = Lazy
.of(() -> new PartTree(queryMethod.getName(), queryMethod.getEntityInformation().getJavaType()));
this.queryMethod = queryMethod;
this.keyValueOperations = keyValueOperations;
this.evaluationContextProvider = evaluationContextProvider;
this.queryCreatorFactory = queryCreatorFactory;
}
@Override
public Object execute(Object[] parameters) {
ParameterAccessor accessor = new ParametersParameterAccessor(getQueryMethod().getParameters(), parameters);
KeyValueQuery<?> query = prepareQuery(parameters);
ResultProcessor processor = queryMethod.getResultProcessor().withDynamicProjection(accessor);
return processor.processResult(doExecute(parameters, query));
}
/**
* @param parameters
* @param query
*/
@Nullable
@SuppressWarnings({ "unchecked", "rawtypes" })
protected Object doExecute(Object[] parameters, KeyValueQuery<?> query) {
if (queryMethod.isPageQuery() || queryMethod.isSliceQuery()) {
Pageable page = (Pageable) parameters[queryMethod.getParameters().getPageableIndex()];
query.setOffset(page.getOffset());
query.setRows(page.getPageSize());
Iterable<?> result = this.keyValueOperations.find(query, queryMethod.getEntityInformation().getJavaType());
long count = queryMethod.isSliceQuery() ? 0
: keyValueOperations.count(query, queryMethod.getEntityInformation().getJavaType());
return new PageImpl(IterableConverter.toList(result), page, count);
} else if (queryMethod.isCollectionQuery()) {
return this.keyValueOperations.find(query, queryMethod.getEntityInformation().getJavaType());
} else if (queryMethod.isQueryForEntity()) {
Iterable<?> result = this.keyValueOperations.find(query, queryMethod.getEntityInformation().getJavaType());
return result.iterator().hasNext() ? result.iterator().next() : null;
} else if (partTree.get().isExistsProjection()) {
return keyValueOperations.exists(query, queryMethod.getEntityInformation().getJavaType());
}
throw new UnsupportedOperationException("Query method not supported");
}
protected KeyValueQuery<?> prepareQuery(Object[] parameters) {
return prepareQuery(createQuery(new ParametersParameterAccessor(getQueryMethod().getParameters(), parameters)),
parameters);
}
@SuppressWarnings({ "rawtypes", "unchecked" })
protected KeyValueQuery<?> prepareQuery(KeyValueQuery<?> instance, Object[] parameters) {
ParametersParameterAccessor accessor = new ParametersParameterAccessor(getQueryMethod().getParameters(),
parameters);
Object criteria = instance.getCriteria();
if (criteria instanceof SpelCriteria || criteria instanceof SpelExpression) {
SpelExpression spelExpression = getSpelExpression(criteria);
EvaluationContext context = this.evaluationContextProvider.getEvaluationContext(getQueryMethod().getParameters(),
parameters);
criteria = new SpelCriteria(spelExpression, context);
}
KeyValueQuery<?> query = new KeyValueQuery(criteria);
Pageable pageable = accessor.getPageable();
Sort sort = accessor.getSort();
query.setOffset(pageable.toOptional().map(Pageable::getOffset).orElse(-1L));
if (pageable.isPaged()) {
query.setRows(pageable.getPageSize());
} else if (instance.getRows() >= 0) {
query.setRows(instance.getRows());
}
query.setSort(sort.isUnsorted() ? instance.getSort() : sort);
return query;
}
private SpelExpression getSpelExpression(Object criteria) {
if (criteria instanceof SpelExpression) {
return (SpelExpression) criteria;
}
if (criteria instanceof SpelCriteria) {
return getSpelExpression(((SpelCriteria) criteria).getExpression());
}
throw new IllegalStateException(String.format("Cannot retrieve SpelExpression from %s", criteria));
}
/**
* Create a {@link KeyValueQuery} given {@link ParameterAccessor}.
*
* @param accessor must not be {@literal null}.
* @return the {@link KeyValueQuery}.
*/
public KeyValueQuery<?> createQuery(ParameterAccessor accessor) {
PartTree tree = this.partTree.get();
AbstractQueryCreator<? extends KeyValueQuery<?>, ?> queryCreator = queryCreatorFactory.queryCreatorFor(tree,
accessor);
KeyValueQuery<?> query = queryCreator.createQuery();
if (tree.isLimiting()) {
query.setRows(tree.getMaxResults());
}
return query;
}
@Override
public QueryMethod getQueryMethod() {
return queryMethod;
}
/**
* Factory class for obtaining {@link AbstractQueryCreator} instances for a given {@link PartTree} and
* {@link ParameterAccessor}.
*
* @author Christoph Strobl
* @since 2.0
*/
public interface QueryCreatorFactory<T extends AbstractQueryCreator<?, ?>> {
T queryCreatorFor(PartTree partTree, ParameterAccessor accessor);
}
/**
* {@link QueryCreatorFactory} implementation instantiating {@link AbstractQueryCreator} via reflection. Looks up and
* caches the constructor on creation.
*
* @author Christoph Strobl
* @since 2.0
*/
private static class ConstructorCachingQueryCreatorFactory
implements QueryCreatorFactory<AbstractQueryCreator<KeyValueQuery<?>, ?>> {
private final Class<?> type;
private final @Nullable Constructor<? extends AbstractQueryCreator<?, ?>> constructor;
ConstructorCachingQueryCreatorFactory(Class<? extends AbstractQueryCreator<?, ?>> type) {
this.type = type;
this.constructor = ClassUtils.getConstructorIfAvailable(type, PartTree.class, ParameterAccessor.class);
}
@Override
@SuppressWarnings("unchecked")
public AbstractQueryCreator<KeyValueQuery<?>, ?> queryCreatorFor(PartTree partTree, ParameterAccessor accessor) {
Assert.state(constructor != null,
() -> String.format("No constructor (PartTree, ParameterAccessor) could be found on type %s", type));
return (AbstractQueryCreator<KeyValueQuery<?>, ?>) BeanUtils.instantiateClass(constructor, partTree, accessor);
}
}
}