JpaRepositoryFactory.java

/*
 * Copyright 2008-2017 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
 *
 *      http://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 static org.springframework.data.querydsl.QuerydslUtils.*;

import java.io.Serializable;
import java.util.Optional;

import javax.persistence.EntityManager;

import org.springframework.data.jpa.provider.PersistenceProvider;
import org.springframework.data.jpa.provider.QueryExtractor;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.data.jpa.repository.query.JpaQueryLookupStrategy;
import org.springframework.data.querydsl.QuerydslPredicateExecutor;
import org.springframework.data.repository.core.RepositoryInformation;
import org.springframework.data.repository.core.RepositoryMetadata;
import org.springframework.data.repository.core.support.RepositoryFactorySupport;
import org.springframework.data.repository.query.EvaluationContextProvider;
import org.springframework.data.repository.query.QueryLookupStrategy;
import org.springframework.data.repository.query.QueryLookupStrategy.Key;
import org.springframework.util.Assert;

/**
 * JPA specific generic repository factory.
 * 
 * @author Oliver Gierke
 * @author Mark Paluch
 * @author Christoph Strobl
 */
public class JpaRepositoryFactory extends RepositoryFactorySupport {

	private final EntityManager entityManager;
	private final QueryExtractor extractor;
	private final CrudMethodMetadataPostProcessor crudMethodMetadataPostProcessor;

	/**
	 * Creates a new {@link JpaRepositoryFactory}.
	 * 
	 * @param entityManager must not be {@literal null}
	 */
	public JpaRepositoryFactory(EntityManager entityManager) {

		Assert.notNull(entityManager, "EntityManager must not be null!");

		this.entityManager = entityManager;
		this.extractor = PersistenceProvider.fromEntityManager(entityManager);
		this.crudMethodMetadataPostProcessor = new CrudMethodMetadataPostProcessor();

		addRepositoryProxyPostProcessor(crudMethodMetadataPostProcessor);
	}

	/* 
	 * (non-Javadoc)
	 * @see org.springframework.data.repository.core.support.RepositoryFactorySupport#setBeanClassLoader(java.lang.ClassLoader)
	 */
	@Override
	public void setBeanClassLoader(ClassLoader classLoader) {
		super.setBeanClassLoader(classLoader);
		this.crudMethodMetadataPostProcessor.setBeanClassLoader(classLoader);
	}

	/*
	 * (non-Javadoc)
	 * @see org.springframework.data.repository.core.support.RepositoryFactorySupport#getTargetRepository(org.springframework.data.repository.core.RepositoryMetadata)
	 */
	@Override
	protected Object getTargetRepository(RepositoryInformation information) {

		SimpleJpaRepository<?, ?> repository = getTargetRepository(information, entityManager);
		repository.setRepositoryMethodMetadata(crudMethodMetadataPostProcessor.getCrudMethodMetadata());

		return repository;
	}

	/**
	 * Callback to create a {@link JpaRepository} instance with the given {@link EntityManager}
	 * 
	 * @param <T>
	 * @param <ID>
	 * @param entityManager
	 * @return
	 */
	protected <T, ID extends Serializable> SimpleJpaRepository<?, ?> getTargetRepository(
			RepositoryInformation information, EntityManager entityManager) {

		JpaEntityInformation<?, Serializable> entityInformation = getEntityInformation(information.getDomainType());

		return getTargetRepositoryViaReflection(information, entityInformation, entityManager);
	}

	/*
	 * (non-Javadoc)
	 * @see org.springframework.data.repository.core.support.RepositoryFactorySupport#getRepositoryBaseClass(org.springframework.data.repository.core.RepositoryMetadata)
	 */
	@Override
	protected Class<?> getRepositoryBaseClass(RepositoryMetadata metadata) {

		if (isQueryDslExecutor(metadata.getRepositoryInterface())) {
			return QuerydslJpaRepository.class;
		} else {
			return SimpleJpaRepository.class;
		}
	}

	/**
	 * Returns whether the given repository interface requires a QueryDsl specific implementation to be chosen.
	 * 
	 * @param repositoryInterface
	 * @return
	 */
	private boolean isQueryDslExecutor(Class<?> repositoryInterface) {

		return QUERY_DSL_PRESENT && QuerydslPredicateExecutor.class.isAssignableFrom(repositoryInterface);
	}

	/* 
	 * (non-Javadoc)
	 * @see org.springframework.data.repository.core.support.RepositoryFactorySupport#getQueryLookupStrategy(org.springframework.data.repository.query.QueryLookupStrategy.Key, org.springframework.data.repository.query.EvaluationContextProvider)
	 */
	@Override
	protected Optional<QueryLookupStrategy> getQueryLookupStrategy(Key key,
			EvaluationContextProvider evaluationContextProvider) {
		return Optional.of(JpaQueryLookupStrategy.create(entityManager, key, extractor, evaluationContextProvider));
	}

	/*
	 * (non-Javadoc)
	 * @see org.springframework.data.repository.core.support.RepositoryFactorySupport#getEntityInformation(java.lang.Class)
	 */
	@Override
	@SuppressWarnings("unchecked")
	public <T, ID> JpaEntityInformation<T, ID> getEntityInformation(Class<T> domainClass) {

		return (JpaEntityInformation<T, ID>) JpaEntityInformationSupport.getEntityInformation(domainClass, entityManager);
	}
}