CRUDServiceImpl.java

/*
 * Copyright 2021 Global Crop Diversity Trust
 *
 * 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.genesys.server.service.impl;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;
import java.util.Objects;

import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;

import org.genesys.blocks.model.EmptyModel;
import org.genesys.blocks.model.VersionedModel;
import org.genesys.server.api.v2.MultiOp;
import org.genesys.server.exception.InvalidApiUsageException;
import org.genesys.server.exception.NotFoundElement;
import org.genesys.server.model.impl.LazyLoading;
import org.genesys.server.service.CRUDService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.InitializingBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.domain.Page;
import org.springframework.data.domain.Pageable;
import org.springframework.data.jpa.repository.JpaRepository;
import org.springframework.orm.ObjectOptimisticLockingFailureException;
import org.springframework.transaction.annotation.Transactional;

import com.querydsl.core.types.dsl.NumberPath;
import com.querydsl.jpa.impl.JPAQuery;
import com.querydsl.jpa.impl.JPAQueryFactory;

/**
 * The basic FilteredCRUDServiceImpl.
 *
 * @param <T> the model type
 * @param <R> the repository type
 */
@Transactional(readOnly = true)
public abstract class CRUDServiceImpl<T extends EmptyModel, R extends JpaRepository<T, Long>> implements InitializingBean, CRUDService<T> {

	protected final Logger LOG = LoggerFactory.getLogger(getClass());

	/** The repository. */
	@Autowired
	protected R repository;

	@Autowired
	protected JPAQueryFactory jpaQueryFactory;

	@PersistenceContext
	protected EntityManager entityManager;

	@Override
	public void afterPropertiesSet() throws Exception {
//		JpaEntityInformationSupport.getEntityInformation(domainClass, entityManager);
//		this.builder = new PathBuilderFactory().create(domainClass);
	}

	// Until .lazyLoad() was in an interface
	protected T _lazyLoad(T entity) {
		if (entity == null) {
			return entity;
		}
		if (entity instanceof LazyLoading<?>) {
			((LazyLoading<?>) entity).lazyLoad();
			return entity;
		} else {
//			throw new RuntimeException("Class " + entity.getClass() + " does not implement LazyLoading<> interface. You must provide an implementation");
			return entity;
		}
	}

	/**
	 * Save the new entity
	 *
	 * @param source incoming data
	 * @return the saved entity
	 */
	@Transactional
	public abstract T create(T source);

	/**
	 * The default MultiOp implementation calls {@link #create(EmptyModel))} for each insert.
	 * If any one insert fails, the transaction is marked as roll-back only and cannot be used for further writes.
	 */
	@Override
	@Transactional
	public MultiOp<T> create(List<T> inserts) {
		var result = new MultiOp<T>();
		result.success = new ArrayList<T>(inserts.size());
		for (T one : inserts) {
			result.success.add(this.create(one));
		}
		return result;
	}

	/**
	 * Fetch entity by id, don't lazy load
	 *
	 * @param id the id
	 * @return the entity
	 */
	public T get(long id) {
		return repository.findById(id).orElseThrow(() -> new NotFoundElement("No record with id=" + id));
	}

	/**
	 * Re-get the entity based on identifiers in the source.
	 *
	 * @param source the source entity
	 * @return the reloaded entity, lazy-loading included
	 */
	public T get(T source) {
		if (source.getId() == null) {
			throw new InvalidApiUsageException("Entity id must be provided.");
		}
		T current = get(source.getId());
		if (current instanceof VersionedModel) {
			VersionedModel sourceAudited = (VersionedModel) source;
			if (sourceAudited.getVersion() == null) {
				throw new InvalidApiUsageException("Entity version must be provided.");
			}
			VersionedModel audited = (VersionedModel) current;
			// check that target has the same version as source
			if (audited.getVersion() != null && !Objects.equals(audited.getVersion(), sourceAudited.getVersion())) {
				throw new ObjectOptimisticLockingFailureException(source.getClass(), source.getId());
			}
		}
		return current;
	}

	/**
	 * Load entity by id and lazy load.
	 *
	 * @param id the id
	 * @return the entity, lazy-loading included
	 */
	public T load(long id) {
		T entity = get(id);
		return _lazyLoad(entity);
	}

	/**
	 * Re-load the entity based on identifiers in the source.
	 *
	 * @param source the source entity
	 * @return the reloaded entity, lazy-loading included
	 */
	@Override
	public final T reload(T source) {
		return _lazyLoad(get(source));
	}

	/**
	 * List records.
	 *
	 * @param page Pageable
	 * @return the page
	 */
	@Override
	public Page<T> list(Pageable page) {
		return repository.findAll(page);
	}

	/**
	 * Save entity.
	 *
	 * @param updated data
	 * @param target current entity
	 * @return the updated entity
	 */
	@Transactional
	public abstract T update(T updated, T target);

	@Transactional
	public T update(T updated) {
		T target = get(updated);
//		entityManager.detach(target);
		return update(updated, target);
	}

	/**
	 * The default MultiOp update implementation calls {@link #update(EmptyModel))} for each update.
	 * If any one update fails, the transaction is marked as roll-back only and cannot be used for further writes.
	 */
	@Override
	@Transactional
	public MultiOp<T> update(List<T> updates) {
		var result = new MultiOp<T>();
		result.success = new ArrayList<T>(updates.size());
		for (T one : updates) {
			result.success.add(this.update(one));
		}
		return result;
	}

	/**
	 * Removes the record.
	 *
	 * @param entity record to delete
	 * @return the removed entity
	 */
	@Transactional
	public T remove(T entity) {
		if (entity == null) {
			throw new InvalidApiUsageException("Entity must be provided.");
		}
		entity = get(entity); // Get entiy inside this transaction so that cascade operations work properly
		repository.delete(entity);
		return entity;
	}

	/**
	 * The default MultiOp delete implementation calls {@link #remove(EmptyModel))} for each update.
	 * If any one delete fails, the transaction is marked as roll-back only and cannot be used for further writes.
	 */
	@Override
	@Transactional
	public MultiOp<T> remove(List<T> deletes) {
		var result = new MultiOp<T>();
		result.success = new ArrayList<T>(deletes.size());
		for (T one : deletes) {
			result.success.add(this.remove(one));
		}
		return result;
	}

	/**
	 * Get a JPA query that (optionally) includes lazy loaded data.
	 *
	 * <example><code>jpaQueryFactory.selectFrom(QTaxonomySpecies.taxonomySpecies).join(...).fetchJoin()</code></example>
	 *
	 * @return a custom JPA query for T
	 */
	protected JPAQuery<T> entityListQuery() {
		return null;
	}

	/**
	 * The Entity id predicate of {link {@link #entityListQuery()}
	 *
	 * <example><code>QTaxonomySpecies.taxonomySpecies.id</code></example>
	 *
	 * @return the number path
	 */
	protected NumberPath<Long> entityIdPredicate() {
		throw new UnsupportedOperationException("You must implement #entityIdPredicate() if you declare #entityListQuery()");
	}

	/**
	 * Get a list of entities with specified IDs in the order specified (if incoming collection of IDs is ordered).
	 * Override this method to lazy load more than default data.
	 *
	 * @param entityIds the entity ids
	 * @return the list
	 */
	public List<T> list(Collection<Long> entityIds) {
		List<T> unsorted;
		if (entityListQuery() != null) {
			unsorted = entityListQuery().where(entityIdPredicate().in(entityIds)).fetch();
		} else {
			unsorted = repository.findAllById(entityIds);
		}
		if (entityIds instanceof List<?>) {
			List<Long> idList = (List<Long>) entityIds;
			unsorted.sort((e1, e2) -> idList.indexOf(e1.getId()) - idList.indexOf(e2.getId()));
		}
		return unsorted;
	}
}