org.springframework.data.jpa.repository.support.QuerydslRepositorySupport Maven / Gradle / Ivy

/*
 * Copyright 2011-2018 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 javax.annotation.Nullable;
import javax.annotation.PostConstruct;
import javax.persistence.EntityManager;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Repository;
import org.springframework.util.Assert;

import com.querydsl.core.dml.DeleteClause;
import com.querydsl.core.dml.UpdateClause;
import com.querydsl.core.types.EntityPath;
import com.querydsl.core.types.dsl.PathBuilder;
import com.querydsl.core.types.dsl.PathBuilderFactory;
import com.querydsl.jpa.JPQLQuery;
import com.querydsl.jpa.impl.JPADeleteClause;
import com.querydsl.jpa.impl.JPAUpdateClause;

/**
 * Base class for implementing repositories using Querydsl library.
 *
 * @author Oliver Gierke
 * @author Mark Paluch
 */
@Repository
public abstract class QuerydslRepositorySupport {

	private final PathBuilder builder;

	private @Nullable EntityManager entityManager;
	private @Nullable Querydsl querydsl;

	/**
	 * Creates a new {@link QuerydslRepositorySupport} instance for the given domain type.
	 *
	 * @param domainClass must not be {@literal null}.
	 */
	public QuerydslRepositorySupport(Class domainClass) {

		Assert.notNull(domainClass, "Domain class must not be null!");
		this.builder = new PathBuilderFactory().create(domainClass);
	}

	/**
	 * Setter to inject {@link EntityManager}.
	 *
	 * @param entityManager must not be {@literal null}.
	 */
	@Autowired
	public void setEntityManager(EntityManager entityManager) {

		Assert.notNull(entityManager, "EntityManager must not be null!");
		this.querydsl = new Querydsl(entityManager, builder);
		this.entityManager = entityManager;
	}

	/**
	 * Callback to verify configuration. Used by containers.
	 */
	@PostConstruct
	public void validate() {
		Assert.notNull(entityManager, "EntityManager must not be null!");
		Assert.notNull(querydsl, "Querydsl must not be null!");
	}

	/**
	 * Returns the {@link EntityManager}.
	 *
	 * @return the entityManager
	 */
	@Nullable
	protected EntityManager getEntityManager() {
		return entityManager;
	}

	/**
	 * Returns a fresh {@link JPQLQuery}.
	 *
	 * @param paths must not be {@literal null}.
	 * @return the Querydsl {@link JPQLQuery}.
	 */
	protected JPQLQuery