Java tutorial
/* * This is eMonocot, a global online biodiversity information resource. * * Copyright 20112015 The Board of Trustees of the Royal Botanic Gardens, Kew and The University of Oxford * * eMonocot is free software: you can redistribute it and/or modify it under the terms of the * GNU Affero General Public License as published by the Free Software Foundation, either version 3 * of the License, or (at your option) any later version. * * eMonocot 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 Affero General Public License for more details. * * The complete text of the GNU Affero General Public License is in the source repository as the file * COPYING. It is also available from <http://www.gnu.org/licenses/>. */ package org.emonocot.persistence.dao.hibernate; import java.util.ArrayList; import java.util.Arrays; import java.util.Collection; import java.util.List; import java.util.Map; import org.apache.commons.beanutils.PropertyUtils; import org.emonocot.model.Base; import org.emonocot.model.hibernate.Fetch; import org.emonocot.persistence.dao.Dao; import org.hibernate.Criteria; import org.hibernate.FetchMode; import org.hibernate.SessionFactory; import org.hibernate.UnresolvableObjectException; import org.hibernate.collection.PersistentCollection; import org.hibernate.criterion.Projections; import org.hibernate.criterion.Restrictions; import org.hibernate.proxy.HibernateProxy; import org.hibernate.proxy.LazyInitializer; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.orm.hibernate3.HibernateObjectRetrievalFailureException; import org.springframework.orm.hibernate3.support.HibernateDaoSupport; /** * * @author ben * * @param <T> * the type of object managed by this dao */ public abstract class DaoImpl<T extends Base> extends HibernateDaoSupport implements Dao<T> { /** * * @param profile * Set the name of the profile * @return a list of Fetch instances */ protected abstract Fetch[] getProfile(String profile); /** * * @param criteria * Set a Criteria instance * @param fetch * Set the name of the fetch profile * @return true if the criteria have been set, false otherwise */ protected boolean enableProfilePreQuery(final Criteria criteria, final String fetch) { boolean setCriteria = false; if (fetch != null) { for (Fetch f : getProfile(fetch)) { if (f.getMode().equals(FetchMode.JOIN)) { criteria.setFetchMode(f.getAssociation(), f.getMode()); setCriteria = true; } } } return setCriteria; } /** * * @param t * Set a the fetched object * @param fetch * Set the name of the fetch profile */ protected void enableProfilePostQuery(final T t, final String fetch) { if (fetch != null && t != null) { Fetch[] fetchDefs = getProfile(fetch); if (fetchDefs == null || fetchDefs.length < 1) { return; } for (Fetch f : fetchDefs) { if (f.getMode().equals(FetchMode.SELECT)) { String association = f.getAssociation(); if (association.indexOf(".") == -1) { initializeProperty(t, f.getAssociation()); } else { List<String> associations = Arrays.asList(association.split("\\.")); initializeProperties(t, associations); } } } } } /** * * @param o the object being initialized * @param associations a list of associations being initialized */ protected void initializeProperties(final Object o, final List<String> associations) { List<String> assocs = new ArrayList<String>(associations); String association = assocs.remove(0); Object associatedObject = initializeProperty(o, association); if (associatedObject == null) { return; } else if (Collection.class.isAssignableFrom(associatedObject.getClass())) { for (Object obj : (Collection) associatedObject) { if (!assocs.isEmpty()) { initializeProperties(obj, assocs); } } } else if (Map.class.isAssignableFrom(associatedObject.getClass())) { for (Object obj : ((Map) associatedObject).values()) { if (!assocs.isEmpty()) { initializeProperties(obj, assocs); } } } else { if (!assocs.isEmpty()) { initializeProperties(associatedObject, assocs); } } } /** * * @param o Set the object * @param association Set the association to initialize */ protected Object initializeProperty(final Object o, final String association) { Object object; try { object = PropertyUtils.getProperty(o, association); } catch (Exception e) { logger.debug("Cannot get proxy " + association + " for class " + o.getClass()); return null; } if (object == null) { return null; } else if (object instanceof HibernateProxy) { ((HibernateProxy) object).getHibernateLazyInitializer().initialize(); LazyInitializer lazyInitializer = ((HibernateProxy) object).getHibernateLazyInitializer(); return lazyInitializer.getImplementation(); } else if (object instanceof PersistentCollection) { ((PersistentCollection) object).forceInitialization(); return object; } else { return object; } } /** * */ protected Class<T> type; /** * * @param newType * Set the type of object handled by this DAO */ public DaoImpl(final Class<T> newType) { this.type = newType; } /** * * @param sessionFactory * Set the session factory */ @Autowired public final void setHibernateSessionFactory(final SessionFactory sessionFactory) { this.setSessionFactory(sessionFactory); } /** * @param identifier * Set the identifier */ public final void deleteById(final Long id) { T t = (T) getSession().load(type, id); getSession().delete(t); } /** * @param identifier * Set the identifier */ public final void delete(final String identifier) { T t = load(identifier); getSession().delete(t); } /** * @param id the primary key * @return the loaded object */ public final T load(final Long id) { return load(id, null); } /** * @param identifier * set the identifier * @return the loaded object */ public final T load(final String identifier) { return load(identifier, null); } /** * @param id * Set the primary key * @return the object, or null if the object cannot be found */ public final T find(final Long id) { return find(id, null); } /** * @param identifier * Set the identifier * @return the object, or null if the object cannot be found */ public final T find(final String identifier) { return find(identifier, null); } /** * @param id * Set the id * @param fetch * Set the fetch profile (can be null) * @return the loaded object */ public T load(final Long id, final String fetch) { Criteria criteria = getSession().createCriteria(type).add(Restrictions.idEq(id)); enableProfilePreQuery(criteria, fetch); T t = (T) criteria.uniqueResult(); if (t == null) { throw new HibernateObjectRetrievalFailureException( new UnresolvableObjectException(id, "Object could not be resolved")); } enableProfilePostQuery(t, fetch); return t; } /** * @param identifier * Set the identifier * @param fetch * Set the fetch profile (can be null) * @return the loaded object */ public T load(final String identifier, final String fetch) { Criteria criteria = getSession().createCriteria(type).add(Restrictions.eq("identifier", identifier)); enableProfilePreQuery(criteria, fetch); T t = (T) criteria.uniqueResult(); if (t == null) { throw new HibernateObjectRetrievalFailureException( new UnresolvableObjectException(identifier, "Object could not be resolved")); } enableProfilePostQuery(t, fetch); return t; } /** * @param identifier * Set the identifer * @param fetch * Set the fetch profile * @return the object or null if it cannot be found */ public T find(final String identifier, final String fetch) { Criteria criteria = getSession().createCriteria(type).add(Restrictions.eq("identifier", identifier)); enableProfilePreQuery(criteria, fetch); T t = (T) criteria.uniqueResult(); enableProfilePostQuery(t, fetch); return t; } /** * @param id * Set the id * @param fetch * Set the fetch profile * @return the object or null if it cannot be found */ public T find(final Long id, final String fetch) { Criteria criteria = getSession().createCriteria(type).add(Restrictions.idEq(id)); enableProfilePreQuery(criteria, fetch); T t = (T) criteria.uniqueResult(); enableProfilePostQuery(t, fetch); return t; } /** * * @param t * The object to save. * @return the saved object */ public final T save(final T t) { getSession().save(t); return t; } /** * * @param t * The object to save. */ public final void saveOrUpdate(final T t) { getSession().saveOrUpdate(t); } /** * * @param t * The object to update. */ public final void update(final T t) { getSession().update(t); } /** * * @param t * The object to merge. * @return the merged object */ public final T merge(final T t) { return (T) getSession().merge(t); } /** * @return the total number of objects */ public final Long count() { Criteria criteria = getSession().createCriteria(type); criteria.setProjection(Projections.rowCount()); return (Long) criteria.uniqueResult(); } /** * @param page Set the offset (in size chunks, 0-based), optional * @param size Set the page size * @param fetch Set the fetch profile to which relations are fetched * @return A list of results */ public final List<T> list(final Integer page, final Integer size, final String fetch) { Criteria criteria = getSession().createCriteria(type); if (size != null) { criteria.setMaxResults(size); if (page != null) { criteria.setFirstResult(page * size); } } return (List<T>) criteria.list(); } }