Java tutorial
/** * Copyright (C) 2012-2015 52North Initiative for Geospatial Open Source * Software GmbH * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published * by the Free Software Foundation. * * If the program is linked with libraries which are licensed under one of * the following licenses, the combination of the program with the linked * library is not considered a "derivative work" of the program: * * - Apache License, version 2.0 * - Apache Software License, version 1.0 * - GNU Lesser General Public License, version 3 * - Mozilla Public License, versions 1.0, 1.1 and 2.0 * - Common Development and Distribution License (CDDL), version 1.0 * * Therefore the distribution of the program linked with libraries licensed * under the aforementioned licenses, is permitted by the copyright holders * if the distribution is compliant with both the GNU General Public * License version 2 and the aforementioned licenses. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General * Public License for more details. */ package org.n52.sos.ds.hibernate.util; import java.util.Collection; import java.util.List; import org.hibernate.Criteria; import org.hibernate.Query; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.dialect.Dialect; import org.hibernate.engine.spi.NamedQueryDefinition; import org.hibernate.engine.spi.NamedSQLQueryDefinition; import org.hibernate.engine.spi.SessionFactoryImplementor; import org.hibernate.engine.spi.SessionImplementor; import org.hibernate.hql.internal.ast.ASTQueryTranslatorFactory; import org.hibernate.hql.internal.ast.QueryTranslatorImpl; import org.hibernate.hql.spi.QueryTranslatorFactory; import org.hibernate.internal.CriteriaImpl; import org.hibernate.internal.SessionImpl; import org.hibernate.loader.criteria.CriteriaJoinWalker; import org.hibernate.loader.criteria.CriteriaQueryTranslator; import org.hibernate.persister.entity.OuterJoinLoadable; import com.google.common.collect.Lists; import com.google.common.collect.Maps; /** * Hibernate helper class. * * @author Carsten Hollmann <c.hollmann@52north.org> * @since 4.0.0 * */ public final class HibernateHelper { /** * Private constructor */ private HibernateHelper() { } /** * Get the SQL query string from Criteria. * * @param criteria * Criteria to get SQL query string from * @return SQL query string from criteria */ public static String getSqlString(Criteria criteria) { CriteriaImpl criteriaImpl = (CriteriaImpl) criteria; SessionImplementor session = criteriaImpl.getSession(); SessionFactoryImplementor factory = session.getFactory(); CriteriaQueryTranslator translator = new CriteriaQueryTranslator(factory, criteriaImpl, criteriaImpl.getEntityOrClassName(), CriteriaQueryTranslator.ROOT_SQL_ALIAS); String[] implementors = factory.getImplementors(criteriaImpl.getEntityOrClassName()); CriteriaJoinWalker walker = new CriteriaJoinWalker( (OuterJoinLoadable) factory.getEntityPersister(implementors[0]), translator, factory, criteriaImpl, criteriaImpl.getEntityOrClassName(), session.getLoadQueryInfluencers()); return walker.getSQLString(); } /** * Get the SQL query string from HQL Query. * * @param query * HQL query to convert to SQL * @return SQL query string from HQL */ public static String getSqlString(Query query, Session session) { final QueryTranslatorFactory ast = new ASTQueryTranslatorFactory(); SessionFactory sessionFactory = session.getSessionFactory(); final QueryTranslatorImpl qt = (QueryTranslatorImpl) ast.createQueryTranslator("id", query.getQueryString(), Maps.newHashMap(), (SessionFactoryImplementor) sessionFactory, null); qt.compile(null, false); return qt.getSQLString(); } /** * Checks if the specified entity is supported. * * @param clazz * the class * * @return if the entity supported */ public static boolean isEntitySupported(Class<?> clazz) { return HibernateMetadataCache.getInstance().isEntitySupported(clazz); } /** * Checks if the specified column is supported by this entity. * * @param clazz * the class * @param column * the column * @return if the column supported */ public static boolean isColumnSupported(Class<?> clazz, String column) { return HibernateMetadataCache.getInstance().isColumnSupported(clazz, column); } /** * Checks if the specified named query is supported. * * @param namedQuery * the named query * @param session * Hibernate session * @return if the named query supported */ public static boolean isNamedQuerySupported(String namedQuery, Session session) { NamedQueryDefinition namedQueryDef = ((SessionImpl) session).getSessionFactory().getNamedQuery(namedQuery); NamedSQLQueryDefinition namedSQLQueryDef = ((SessionImpl) session).getSessionFactory() .getNamedSQLQuery(namedQuery); return namedQueryDef != null || namedSQLQueryDef != null; } public static Dialect getDialect(Session session) { return ((SessionFactoryImplementor) session.getSessionFactory()).getDialect(); } public static List<List<Long>> getValidSizedLists(Collection<Long> queryIds) { List<Long> queryIdsList = Lists.newArrayList(queryIds); List<List<Long>> lists = Lists.newArrayList(); if (queryIds.size() > HibernateConstants.LIMIT_EXPRESSION_DEPTH) { int startIndex = 0; int endIndex = HibernateConstants.LIMIT_EXPRESSION_DEPTH - 1; while (startIndex < queryIdsList.size() - 1) { if (endIndex > (queryIdsList.size())) { endIndex = (queryIdsList.size()); } lists.add(queryIdsList.subList(startIndex, endIndex)); startIndex = endIndex; endIndex = endIndex + HibernateConstants.LIMIT_EXPRESSION_DEPTH - 1; } } else { lists.add(queryIdsList); } return lists; } /** * Check if the requested function is supported by the requested dialect * * @param dialect * Dialect to check * @param function * Function to check * @return <code>true</code>, if function is supported */ public static boolean supportsFunction(Dialect dialect, String function) { return dialect.getFunctions().containsKey(function); } }