Java tutorial
/* * Copyright 2015 herd contributors * * 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.finra.herd.dao.impl; import java.util.ArrayList; import java.util.Collection; import java.util.List; import javax.persistence.criteria.CriteriaBuilder; import javax.persistence.criteria.CriteriaQuery; import javax.persistence.criteria.Join; import javax.persistence.criteria.Order; import javax.persistence.criteria.Predicate; import javax.persistence.criteria.Root; import org.apache.commons.collections4.CollectionUtils; import org.springframework.stereotype.Repository; import org.finra.herd.dao.AttributeValueListDao; import org.finra.herd.model.api.xml.AttributeValueListKey; import org.finra.herd.model.jpa.AttributeValueListEntity; import org.finra.herd.model.jpa.AttributeValueListEntity_; import org.finra.herd.model.jpa.NamespaceEntity; import org.finra.herd.model.jpa.NamespaceEntity_; @Repository public class AttributeValueListDaoImpl extends AbstractHerdDao implements AttributeValueListDao { @Override public AttributeValueListEntity getAttributeValueListByKey(AttributeValueListKey attributeValueListKey) { // Create the criteria builder and the criteria. CriteriaBuilder builder = entityManager.getCriteriaBuilder(); CriteriaQuery<AttributeValueListEntity> criteria = builder.createQuery(AttributeValueListEntity.class); // The criteria root is the attribute value list. Root<AttributeValueListEntity> attributeValueListEntityRoot = criteria.from(AttributeValueListEntity.class); // Join to the other tables we can filter on. Join<AttributeValueListEntity, NamespaceEntity> namespaceEntityJoin = attributeValueListEntityRoot .join(AttributeValueListEntity_.namespace); // Create the standard restrictions (i.e. the standard where clauses). List<Predicate> predicates = new ArrayList<>(); predicates.add(builder.equal(builder.upper(namespaceEntityJoin.get(NamespaceEntity_.code)), attributeValueListKey.getNamespace().toUpperCase())); predicates .add(builder.equal(builder.upper(attributeValueListEntityRoot.get(AttributeValueListEntity_.name)), attributeValueListKey.getAttributeValueListName().toUpperCase())); // Add all clauses to the query. criteria.select(attributeValueListEntityRoot) .where(builder.and(predicates.toArray(new Predicate[predicates.size()]))); // Execute the query and return the results. return executeSingleResultQuery(criteria, String.format( "Found more than one attribute value list with parameters {namespace=\"%s\", attribute_value_name=\"%s\"}.", attributeValueListKey.getNamespace(), attributeValueListKey.getAttributeValueListName())); } @Override public List<AttributeValueListKey> getAttributeValueLists(Collection<String> namespaces) { // Create the criteria builder and the criteria. CriteriaBuilder builder = entityManager.getCriteriaBuilder(); CriteriaQuery<AttributeValueListEntity> criteria = builder.createQuery(AttributeValueListEntity.class); // The criteria root is the attribute value list entity. Root<AttributeValueListEntity> attributeValueListEntityRoot = criteria.from(AttributeValueListEntity.class); // Join to the other tables we can filter on. Join<AttributeValueListEntity, NamespaceEntity> namespaceEntityJoin = attributeValueListEntityRoot .join(AttributeValueListEntity_.namespace); // Create the standard restrictions (i.e. the standard where clauses). List<Predicate> predicates = new ArrayList<>(); if (CollectionUtils.isNotEmpty(namespaces)) { predicates.add(namespaceEntityJoin.get(NamespaceEntity_.code).in(namespaces)); } // Order the results by namespace and job name. List<Order> orderBy = new ArrayList<>(); orderBy.add(builder.asc(namespaceEntityJoin.get(NamespaceEntity_.code))); orderBy.add(builder.asc(attributeValueListEntityRoot.get(AttributeValueListEntity_.name))); // Add all clauses to the query. criteria.select(attributeValueListEntityRoot) .where(builder.and(predicates.toArray(new Predicate[predicates.size()]))).orderBy(orderBy); // Execute the query and build a list of keys. List<AttributeValueListKey> attributeValueListKeys = new ArrayList<>(); for (AttributeValueListEntity attributeValueListEntity : entityManager.createQuery(criteria) .getResultList()) { attributeValueListKeys.add(new AttributeValueListKey(attributeValueListEntity.getNamespace().getCode(), attributeValueListEntity.getName())); } return attributeValueListKeys; } }