/*
* Copyright 2017-2020 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.jpa.repository.support;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Optional;
import javax.persistence.EntityManager;
import org.springframework.data.jpa.repository.EntityGraph;
import org.springframework.data.jpa.repository.query.Jpa21Utils;
import org.springframework.data.jpa.repository.query.JpaEntityGraph;
import org.springframework.data.util.Optionals;
import org.springframework.util.Assert;
Default implementation of QueryHints
. Author: Christoph Strobl, Oliver Gierke, Jens Schauder Since: 2.0
/**
* Default implementation of {@link QueryHints}.
*
* @author Christoph Strobl
* @author Oliver Gierke
* @author Jens Schauder
* @since 2.0
*/
class DefaultQueryHints implements QueryHints {
private final JpaEntityInformation<?, ?> information;
private final CrudMethodMetadata metadata;
private final Optional<EntityManager> entityManager;
private final boolean forCounts;
Creates a new DefaultQueryHints
instance for the given JpaEntityInformation
, CrudMethodMetadata
, EntityManager
and whether to include fetch graphs. Params: - information – must not be null.
- metadata – must not be null.
- entityManager – must not be null.
- forCounts –
/**
* Creates a new {@link DefaultQueryHints} instance for the given {@link JpaEntityInformation},
* {@link CrudMethodMetadata}, {@link EntityManager} and whether to include fetch graphs.
*
* @param information must not be {@literal null}.
* @param metadata must not be {@literal null}.
* @param entityManager must not be {@literal null}.
* @param forCounts
*/
private DefaultQueryHints(JpaEntityInformation<?, ?> information, CrudMethodMetadata metadata,
Optional<EntityManager> entityManager, boolean forCounts) {
this.information = information;
this.metadata = metadata;
this.entityManager = entityManager;
this.forCounts = forCounts;
}
Creates a new QueryHints
instance for the given JpaEntityInformation
, CrudMethodMetadata
and EntityManager
. Params: - information – must not be null.
- metadata – must not be null.
Returns:
/**
* Creates a new {@link QueryHints} instance for the given {@link JpaEntityInformation}, {@link CrudMethodMetadata}
* and {@link EntityManager}.
*
* @param information must not be {@literal null}.
* @param metadata must not be {@literal null}.
* @return
*/
public static QueryHints of(JpaEntityInformation<?, ?> information, CrudMethodMetadata metadata) {
Assert.notNull(information, "JpaEntityInformation must not be null!");
Assert.notNull(metadata, "CrudMethodMetadata must not be null!");
return new DefaultQueryHints(information, metadata, Optional.empty(), false);
}
/*
* (non-Javadoc)
* @see org.springframework.data.jpa.repository.support.QueryHints#withFetchGraphs()
*/
@Override
public QueryHints withFetchGraphs(EntityManager em) {
return new DefaultQueryHints(this.information, this.metadata, Optional.of(em), this.forCounts);
}
/*
* (non-Javadoc)
* @see org.springframework.data.jpa.repository.support.QueryHints#forCounts()
*/
@Override
public QueryHints forCounts() {
return new DefaultQueryHints(this.information, this.metadata, this.entityManager, true);
}
/*
* (non-Javadoc)
* @see java.lang.Iterable#iterator()
*/
@Override
public Iterator<Entry<String, Object>> iterator() {
return asMap().entrySet().iterator();
}
/*
* (non-Javadoc)
* @see org.springframework.data.jpa.repository.support.QueryHints#asMap()
*/
@Override
public Map<String, Object> asMap() {
Map<String, Object> hints = new HashMap<>();
if (forCounts) {
hints.putAll(metadata.getQueryHintsForCount());
} else {
hints.putAll(metadata.getQueryHints());
}
hints.putAll(getFetchGraphs());
return hints;
}
private Map<String, Object> getFetchGraphs() {
return Optionals
.mapIfAllPresent(entityManager, metadata.getEntityGraph(),
(em, graph) -> Jpa21Utils.tryGetFetchGraphHints(em, getEntityGraph(graph), information.getJavaType()))
.orElse(Collections.emptyMap());
}
private JpaEntityGraph getEntityGraph(EntityGraph entityGraph) {
String fallbackName = information.getEntityName() + "." + metadata.getMethod().getName();
return new JpaEntityGraph(entityGraph, fallbackName);
}
}