Java tutorial
/**************************************************************** * Licensed to the AOS Community (AOS) under one or more * * contributor license agreements. See the NOTICE file * * distributed with this work for additional information * * regarding copyright ownership. The AOS licenses this file * * to you 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 io.datalayer.sql.dao.impl; import io.datalayer.sql.dao.GenericDao; import io.datalayer.sql.dao.finder.FinderArgumentTypeFactory; import io.datalayer.sql.dao.finder.FinderExecutor; import io.datalayer.sql.dao.finder.FinderNamingStrategy; import io.datalayer.sql.dao.finder.impl.SimpleFinderArgumentTypeFactory; import io.datalayer.sql.dao.finder.impl.SimpleFinderNamingStrategy; import java.io.Serializable; import java.lang.reflect.Method; import java.util.Collection; import java.util.Iterator; import java.util.List; import org.hibernate.Query; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.type.Type; import org.springframework.orm.hibernate3.SessionFactoryUtils; /** * Hibernate implementation of GenericDao A typesafe implementation of CRUD and * finder methods based on Hibernate and Spring AOP The finders are implemented * through the executeFinder method. Normally called by the * FinderIntroductionInterceptor */ public class GenericDaoHibernateImpl<T, PK extends Serializable> implements GenericDao<T, PK>, FinderExecutor { private SessionFactory sessionFactory; // Default. Can override in config. private FinderNamingStrategy namingStrategy = new SimpleFinderNamingStrategy(); // Default. Can override in config. private FinderArgumentTypeFactory argumentTypeFactory = new SimpleFinderArgumentTypeFactory(); private Class<T> type; public GenericDaoHibernateImpl(Class<T> type) { this.type = type; } public PK create(T o) { return (PK) getSession().save(o); } public T read(PK id) { return (T) getSession().get(type, id); } public void update(T o) { getSession().update(o); } public void delete(T o) { getSession().delete(o); } public List<T> executeFinder(Method method, final Object[] queryArgs) { final Query namedQuery = prepareQuery(method, queryArgs); return (List<T>) namedQuery.list(); } public Iterator<T> iterateFinder(Method method, final Object[] queryArgs) { final Query namedQuery = prepareQuery(method, queryArgs); return (Iterator<T>) namedQuery.iterate(); } // public ScrollableResults scrollFinder(Method method, final Object[] // queryArgs) // { // final Query namedQuery = prepareQuery(method, queryArgs); // return (ScrollableResults) namedQuery.scroll(); // } private Query prepareQuery(Method method, Object[] queryArgs) { final String queryName = getNamingStrategy().queryNameFromMethod(type, method); final Query namedQuery = getSession().getNamedQuery(queryName); String[] namedParameters = namedQuery.getNamedParameters(); if (namedParameters.length == 0) { setPositionalParams(queryArgs, namedQuery); } else { setNamedParams(namedParameters, queryArgs, namedQuery); } return namedQuery; } private void setPositionalParams(Object[] queryArgs, Query namedQuery) { // Set parameter. Use custom Hibernate Type if necessary if (queryArgs != null) { for (int i = 0; i < queryArgs.length; i++) { Object arg = queryArgs[i]; Type argType = getArgumentTypeFactory().getArgumentType(arg); if (argType != null) { namedQuery.setParameter(i, arg, argType); } else { namedQuery.setParameter(i, arg); } } } } private void setNamedParams(String[] namedParameters, Object[] queryArgs, Query namedQuery) { // Set parameter. Use custom Hibernate Type if necessary if (queryArgs != null) { for (int i = 0; i < queryArgs.length; i++) { Object arg = queryArgs[i]; Type argType = getArgumentTypeFactory().getArgumentType(arg); if (argType != null) { namedQuery.setParameter(namedParameters[i], arg, argType); } else { if (arg instanceof Collection) { namedQuery.setParameterList(namedParameters[i], (Collection) arg); } else { namedQuery.setParameter(namedParameters[i], arg); } } } } } public Session getSession() { boolean allowCreate = true; return SessionFactoryUtils.getSession(sessionFactory, allowCreate); } public void setSessionFactory(SessionFactory sessionFactory) { this.sessionFactory = sessionFactory; } public FinderNamingStrategy getNamingStrategy() { return namingStrategy; } public void setNamingStrategy(FinderNamingStrategy namingStrategy) { this.namingStrategy = namingStrategy; } public FinderArgumentTypeFactory getArgumentTypeFactory() { return argumentTypeFactory; } public void setArgumentTypeFactory(FinderArgumentTypeFactory argumentTypeFactory) { this.argumentTypeFactory = argumentTypeFactory; } }