Java tutorial
/** * Copyright (C) 2008 University of Pittsburgh * * * This file is part of Open EpiCenter * * Open EpiCenter is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * Open EpiCenter 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. * * You should have received a copy of the GNU General Public License * along with Open EpiCenter. If not, see <http://www.gnu.org/licenses/>. * * * */ package com.hmsinc.epicenter.model; import java.io.Serializable; import java.lang.reflect.Method; import java.util.ArrayList; import java.util.Collection; import java.util.List; import javax.persistence.EntityManager; import javax.persistence.PersistenceContext; import javax.persistence.PersistenceContextType; import org.apache.commons.lang.Validate; import org.hibernate.Criteria; import org.hibernate.Session; import org.hibernate.criterion.Projections; import org.hibernate.criterion.Restrictions; import org.hibernate.metadata.ClassMetadata; import org.hibernate.persister.entity.AbstractEntityPersister; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import com.hmsinc.epicenter.model.util.ModelUtils; /** * A base implementation of a domain object repository for Hibernate/JPA. * * @author <a href="mailto:steve.kondik@hmsinc.com">Steve Kondik</a> * @version $Id:AbstractJPARepository.java 220 2007-07-17 14:59:08Z steve.kondik $ */ @org.springframework.stereotype.Repository public abstract class AbstractJPARepository<T extends Serializable, ID extends Serializable> implements Repository<T, ID> { protected static final String CACHE_HINT = "org.hibernate.cacheable"; protected final Logger logger = LoggerFactory.getLogger(this.getClass()); @PersistenceContext(type = PersistenceContextType.TRANSACTION, unitName = "epicenter-model") protected EntityManager entityManager; private static final boolean isOldHibernateVersion; // Try to detect Hibernate API breakage so we can run on Mergence 1.2 static { boolean old = false; try { final Method m = AbstractEntityPersister.class.getMethod("getCacheAccessStrategy"); if (m == null) { old = true; } } catch (NoSuchMethodException e) { old = true; } isOldHibernateVersion = old; } /* (non-Javadoc) * @see com.hmsinc.epicenter.model.Repository#load(ID, java.lang.Class) */ public <L extends T> L load(final ID id, final Class<L> type) { Validate.notNull(type, "Type must be specified."); return entityManager.find(type, id); } /* (non-Javadoc) * @see com.hmsinc.epicenter.model.Repository#getReference(ID, java.lang.Class) */ public <L extends T> L getReference(final ID id, final Class<L> type) { return entityManager.getReference(type, id); } /* (non-Javadoc) * @see com.hmsinc.epicenter.model.Repository#getReferences(java.util.List, java.lang.Class) */ public <L extends T> List<L> getReferences(final Collection<ID> ids, final Class<L> type) { final List<L> references = new ArrayList<L>(); for (ID id : ids) { references.add(entityManager.getReference(type, id)); } return references; } /* (non-Javadoc) * @see com.hmsinc.epicenter.model.Repository#update(T) */ public void update(final T t) { entityManager.merge(t); } /* (non-Javadoc) * @see com.hmsinc.epicenter.model.Repository#update(java.util.List) */ public void update(final Collection<? extends T> t) { for (T obj : t) { entityManager.merge(obj); } } /* (non-Javadoc) * @see com.hmsinc.epicenter.model.Repository#save(T) */ public void save(final T t) { entityManager.persist(t); } /* (non-Javadoc) * @see com.hmsinc.epicenter.model.Repository#save(java.util.List) */ public void save(final Collection<? extends T> t) { for (T obj : t) { entityManager.persist(obj); } } /* (non-Javadoc) * @see com.hmsinc.epicenter.model.Repository#delete(T) */ public void delete(final T t) { entityManager.remove(t); } /* (non-Javadoc) * @see com.hmsinc.epicenter.model.Repository#delete(java.util.Collection) */ public void delete(final Collection<? extends T> t) { for (T obj : t) { entityManager.remove(obj); } } /* (non-Javadoc) * @see com.hmsinc.epicenter.model.Repository#refresh(java.io.Serializable) */ public void refresh(T t) { entityManager.refresh(t); } /* (non-Javadoc) * @see com.hmsinc.epicenter.model.Repository#getList(java.lang.Class) */ @SuppressWarnings("unchecked") public <L extends T> List<L> getList(final Class<L> type) { Validate.notNull(type, "Type must be specified."); // Check to see if we should cache this entity first.. boolean cache = true; if (!isOldHibernateVersion) { final ClassMetadata metadata = ((Session) entityManager.getDelegate()).getSessionFactory() .getClassMetadata(type); if (metadata instanceof AbstractEntityPersister) { final AbstractEntityPersister p = (AbstractEntityPersister) metadata; if (p.getCacheAccessStrategy() == null) { cache = false; } } } return ModelUtils.criteriaQuery(entityManager, type).setCacheable(cache).list(); } /* (non-Javadoc) * @see com.hmsinc.epicenter.model.Repository#findBy(java.lang.Class, java.lang.String, java.lang.Object) */ @SuppressWarnings("unchecked") public <L extends T> List<L> findBy(Class<L> type, String property, Object value) { Validate.notNull(type, "Type must be specified."); Validate.notNull(property, "Property must be specified."); final Criteria c = ModelUtils.criteriaQuery(entityManager, type); c.add(Restrictions.eq(property, value)); return c.list(); } /* (non-Javadoc) * @see com.hmsinc.epicenter.model.Repository#count(java.lang.Class) */ public <L extends T> long count(final Class<L> type) { Validate.notNull(type, "Type must be specified."); final Criteria c = ModelUtils.criteriaQuery(entityManager, type); c.setProjection(Projections.rowCount()); return ((Integer) c.uniqueResult()).longValue(); } public void evict(Object t) { ((Session) entityManager.getDelegate()).evict(t); } /* (non-Javadoc) * @see com.hmsinc.epicenter.model.Repository#flush() */ public void flush() { entityManager.flush(); } /* (non-Javadoc) * @see com.hmsinc.epicenter.model.Repository#getTableForEntity(java.lang.Class) */ public <L extends T> String getTableForEntity(Class<L> type) { Validate.notNull(type, "Type must be specified."); String ret = null; final ClassMetadata metadata = ((Session) entityManager.getDelegate()).getSessionFactory() .getClassMetadata(type); if (metadata instanceof AbstractEntityPersister) { ret = ((AbstractEntityPersister) metadata).getTableName(); } return ret; } }