Java tutorial
/** * Copyright 2011 Intuit Inc. All Rights Reserved */ package com.intuit.tank.dao; /* * #%L * Data Access * %% * Copyright (C) 2011 - 2015 Intuit Inc. * %% * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * which accompanies this distribution, and is available at * http://www.eclipse.org/legal/epl-v10.html * #L% */ import java.lang.reflect.ParameterizedType; import java.util.ArrayList; import java.util.Collection; import java.util.List; import javax.annotation.Nonnull; import javax.annotation.Nullable; import javax.persistence.EntityManager; import javax.persistence.NoResultException; import javax.persistence.PersistenceException; import javax.persistence.TypedQuery; import javax.persistence.criteria.CriteriaBuilder; import javax.persistence.criteria.CriteriaQuery; import javax.validation.ConstraintViolation; import javax.validation.ConstraintViolationException; import org.apache.log4j.Logger; import org.hibernate.HibernateException; import org.hibernate.LockOptions; import org.hibernate.classic.Session; import org.hibernate.envers.AuditReader; import org.hibernate.envers.AuditReaderFactory; import com.intuit.tank.project.BaseEntity; import com.intuit.tank.view.filter.ViewFilterType; /** * BaseDao * * @author dangleton * */ public abstract class BaseDao<T_ENTITY extends BaseEntity> { private static final Logger LOG = Logger.getLogger(BaseDao.class); private static final ThreadLocalEntityManagerProvider emProvider = new ThreadLocalEntityManagerProvider(); private Class<T_ENTITY> entityClass; private boolean reloadEntities; /** * @param entityClass */ @SuppressWarnings("unchecked") protected BaseDao() { // entity ManagerFactory = Persistence.createEntityManagerFactory("wats"); @SuppressWarnings("rawtypes") Class getClass = (Class) getClass(); ParameterizedType genericSuperclass = (ParameterizedType) getClass.getGenericSuperclass(); this.entityClass = (Class<T_ENTITY>) genericSuperclass.getActualTypeArguments()[0]; } /** * @return the reloadEntities */ boolean isReloadEntities() { return reloadEntities; } /** * @param reloadEntities * the reloadEntities to set */ void setReloadEntities(boolean reloadEntities) { this.reloadEntities = reloadEntities; } /** * * @param id * @return */ public int getHeadRevisionNumber(int id) { int result = 0; try { begin(); AuditReader reader = AuditReaderFactory.get(getEntityManager()); List<Number> revisions = reader.getRevisions(entityClass, id); if (!revisions.isEmpty()) { result = revisions.get(revisions.size() - 1).intValue(); } commit(); } catch (NoResultException e) { LOG.warn("No result for revision with id of " + id); } finally { cleanup(); } return result; } /** * gets the entity at the specified revision * * @param id * the id of the entity to fetch * @param revisionNumber * the revision number * @return the entity or null if no entity can be found */ @Nullable public T_ENTITY findRevision(int id, int revisionNumber) { T_ENTITY result = null; try { begin(); AuditReader reader = AuditReaderFactory.get(getEntityManager()); result = reader.find(entityClass, id, revisionNumber); commit(); } catch (NoResultException e) { LOG.warn("No result for revision " + revisionNumber + " with id of " + id); } finally { cleanup(); } return result; } /** * Persist or update the entity. Persist if the primary key is null update otherwise. * * @param entity * the entity to persist * @return the persisted unattached entity. * @throws HibernateException * if there is an error in persistence */ @Nonnull public T_ENTITY saveOrUpdate(@Nonnull T_ENTITY entity) throws HibernateException { try { EntityManager em = getEntityManager(); begin(); if (entity.getId() == 0) { em.persist(entity); } else { entity = em.merge(entity); } commit(); } catch (ConstraintViolationException e) { for (@SuppressWarnings("rawtypes") ConstraintViolation v : e.getConstraintViolations()) { LOG.warn("ConstraintViolation for " + entityClass.getSimpleName() + " " + "[property: " + v.getPropertyPath().iterator().next().getName() + "]" + " " + "[message: " + v.getMessage() + "]" + " " + "[invalid value: " + v.getInvalidValue() + "]"); } throw e; } catch (PersistenceException e) { // wrapped in a Persistence Exception if (e.getCause() instanceof ConstraintViolationException) { ConstraintViolationException cve = (ConstraintViolationException) e.getCause(); for (@SuppressWarnings("rawtypes") ConstraintViolation v : cve.getConstraintViolations()) { LOG.warn("ConstraintViolation for " + entityClass.getSimpleName() + " " + "[property: " + v.getPropertyPath().iterator().next().getName() + "]" + " " + "[message: " + v.getMessage() + "]" + " " + "[invalid value: " + v.getInvalidValue() + "]"); } throw cve; } throw e; } catch (Exception e) { e.printStackTrace(); throw new RuntimeException(e); } finally { cleanup(); } return entity; } /** * * @param entities */ public List<T_ENTITY> persistCollection(Collection<T_ENTITY> entities) { List<T_ENTITY> ret = new ArrayList<T_ENTITY>(); try { EntityManager em = getEntityManager(); begin(); int count = 0; for (T_ENTITY entity : entities) { if (entity.getId() == 0) { em.persist(entity); } else { entity = em.merge(entity); } ret.add(entity); if (++count % 1000 == 0) { em.flush(); em.clear(); } } commit(); } catch (ConstraintViolationException e) { for (@SuppressWarnings("rawtypes") ConstraintViolation v : e.getConstraintViolations()) { LOG.warn("ConstraintViolation for " + entityClass.getSimpleName() + " " + "[property: " + v.getPropertyPath().iterator().next().getName() + "]" + " " + "[message: " + v.getMessage() + "]" + " " + "[invalid value: " + v.getInvalidValue() + "]"); } throw e; } catch (PersistenceException e) { // wrapped in a Persistence Exception if (e.getCause() instanceof ConstraintViolationException) { ConstraintViolationException cve = (ConstraintViolationException) e.getCause(); for (@SuppressWarnings("rawtypes") ConstraintViolation v : cve.getConstraintViolations()) { LOG.warn("ConstraintViolation for " + entityClass.getSimpleName() + " " + "[property: " + v.getPropertyPath().iterator().next().getName() + "]" + " " + "[message: " + v.getMessage() + "]" + " " + "[invalid value: " + v.getInvalidValue() + "]"); } throw cve; } throw e; } catch (Exception e) { LOG.error("Error storing object to persistent storage: " + e.toString(), e); throw new RuntimeException(e); } finally { cleanup(); } return ret; } /** * Deletes the entity from the datastore and applies cascade rules. * * @param id * the id of the entity to delete * @throws HibernateException * if there is an error in persistence */ public void delete(@Nonnull Integer id) throws HibernateException { EntityManager em = getEntityManager(); try { begin(); T_ENTITY entity = em.find(entityClass, id); if (entity != null) { LOG.debug("deleting entity " + entity.toString()); em.remove(entity); } commit(); } finally { cleanup(); } } /** * Deletes the entity from the datastore and applies cascade rules. * * @param entity * the entity to delete * @throws HibernateException * if there is an error in persistence */ public void delete(@Nonnull T_ENTITY entity) throws HibernateException { delete(entity.getId()); } /** * Gets an entity by the id or null if no entity exists with the specified id. * * @param id * the primary key * @return the entity or null */ @Nullable public T_ENTITY findById(@Nonnull Integer id) { T_ENTITY result = null; try { begin(); result = getEntityManager().find(entityClass, id); if (reloadEntities && result != null) { getHibernateSession().refresh(result, LockOptions.READ); } commit(); } finally { cleanup(); } return result; } /** * Finds all where in IDs * * @param ids * @return */ @Nonnull public List<T_ENTITY> findForIds(@Nonnull List<Integer> ids) { String prefix = "x"; NamedParameter parameter = new NamedParameter(BaseEntity.PROPERTY_ID, "id", ids); StringBuilder sb = new StringBuilder(); sb.append(buildQlSelect(prefix)).append(startWhere()) .append(buildWhereClause(Operation.IN, prefix, parameter)); return listWithJQL(sb.toString(), parameter); } /** * Finds all Objects of type T_ENTITY * * @return the nonnull list of entities * @throws HibernateException * if there is an error in persistence */ @Nonnull public List<T_ENTITY> findAll() throws HibernateException { List<T_ENTITY> results = null; // try { EntityManager em = getEntityManager(); // begin(); CriteriaBuilder cb = em.getCriteriaBuilder(); CriteriaQuery<T_ENTITY> query = cb.createQuery(entityClass); query.from(entityClass); results = em.createQuery(query).getResultList(); // commit(); // } finally { // cleanup(); // } return results; } /** * Find all objects of type T_ENTITY that satisfy the ViewFilterType * * @param viewFilter * @return the list of entities that satisfy the filter */ public List<T_ENTITY> findFiltered(ViewFilterType viewFilter) { String prefix = "x"; List<T_ENTITY> ret = null; if (viewFilter != viewFilter.ALL) { NamedParameter parameter = new NamedParameter(BaseEntity.PROPERTY_CREATE, "createDate", ViewFilterType.getViewFilterDate(viewFilter)); StringBuilder sb = new StringBuilder(); sb.append(buildQlSelect(prefix)).append(startWhere()) .append(buildWhereClause(Operation.GREATER_THAN, prefix, parameter)); sb.append(buildSortOrderClause(SortDirection.DESC, prefix, BaseEntity.PROPERTY_CREATE)); ret = listWithJQL(sb.toString(), parameter); } else { StringBuilder sb = new StringBuilder(); sb.append(buildQlSelect(prefix)) .append(buildSortOrderClause(SortDirection.DESC, prefix, BaseEntity.PROPERTY_CREATE)); ret = listWithJQL(sb.toString()); } return ret; } /** * * @param qlString * @param params * @return */ @Nullable public T_ENTITY findOneWithJQL(String qlString, NamedParameter... params) { T_ENTITY result = null; try { EntityManager em = getEntityManager(); begin(); TypedQuery<T_ENTITY> query = em.createQuery(qlString, entityClass); for (NamedParameter param : params) { query.setParameter(param.getName(), param.getValue()); } result = query.getSingleResult(); commit(); } catch (Exception e) { LOG.info("no entity matching query"); } finally { cleanup(); } return result; } /** * returns list of entities meeting the specified criteria. * * @param criterion * varargs criterion. (use something like Restrictions.eq(propertyName, value);) null criterion returns * all. * @param sortOrder * the Order Object. Null value indicates no sort order. * @return the non null list. * @throws HibernateException * if there is an error in persistence */ @Nonnull public List<T_ENTITY> listWithJQL(String qlString, NamedParameter... params) { List<T_ENTITY> result = null; try { EntityManager em = getEntityManager(); begin(); TypedQuery<T_ENTITY> query = em.createQuery(qlString, entityClass); for (NamedParameter param : params) { query.setParameter(param.getName(), param.getValue()); } result = query.getResultList(); commit(); } finally { cleanup(); } return result; } protected String buildQlSelect(String prefix) { return new StringBuilder().append("SELECT ").append(prefix).append(" FROM ").append(entityClass.getName()) .append(" AS ").append(prefix).append(" ").toString(); } protected String buildWhereClause(Operation op, String prefix, NamedParameter param) { if (op == Operation.NULL || op == Operation.NOT_NULL) { return buildFieldId(prefix, param.getField()) + " " + op.getRepresentation(); } return buildFieldId(prefix, param.getField()) + buildParameterName(op, param.getName()); } protected String buildFieldId(String prefix, String field) { return " " + prefix + "." + field + " "; } protected String buildParameterName(Operation op, String name) { return " " + op.getRepresentation() + " :" + name + op.getEnding() + " "; } protected String buildSortOrderClause(SortDirection direction, String prefix, String field) { return " ORDER BY " + prefix + "." + field + " " + direction.name(); } /** * @return */ protected String startWhere() { return " WHERE "; } /** * @return */ protected String getAnd() { return " AND "; } /** * Gets an open hibernate session. * * @return the session */ protected Session getHibernateSession() { Session s = (Session) getEntityManager().getDelegate(); return s; } /** * Gets a JPA EntityManager * * @return the entityManager */ protected EntityManager getEntityManager() { return emProvider.get().getEntityManager(); } /** * @return the emProvider */ protected ThreadLocalEntityManagerProvider getEmProvider() { return emProvider; } protected void begin() { emProvider.get().startTrasaction(this); } protected void commit() { emProvider.get().commitTransaction(this); } protected void cleanup() { emProvider.get().cleanup(this); } public static class ThreadLocalEntityManagerProvider extends ThreadLocal<TransactionContainer> { public TransactionContainer initialValue() { return new TransactionContainer(); } } }