Java tutorial
/* * Copyright (c) 2009-2013, 2015 Eike Stepper (Berlin, Germany) and others. * 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 * * Contributors: * Martin Taal - initial API and implementation * Eike Stepper - maintenance */ package org.eclipse.emf.cdo.server.internal.hibernate; import org.eclipse.emf.cdo.common.branch.CDOBranchVersion; import org.eclipse.emf.cdo.common.id.CDOID; import org.eclipse.emf.cdo.common.revision.CDORevision; import org.eclipse.emf.cdo.common.util.CDOQueryInfo; import org.eclipse.emf.cdo.internal.common.branch.CDOBranchVersionImpl; import org.eclipse.emf.cdo.server.IQueryContext; import org.eclipse.emf.cdo.server.IQueryHandler; import org.eclipse.emf.cdo.server.hibernate.IHibernateStore; import org.eclipse.emf.cdo.server.internal.hibernate.tuplizer.WrappedHibernateList; import org.eclipse.emf.cdo.spi.common.revision.InternalCDORevision; import org.eclipse.emf.cdo.spi.common.revision.InternalCDORevisionManager; import org.eclipse.emf.ecore.EReference; import org.eclipse.emf.ecore.EStructuralFeature; import org.eclipse.emf.teneo.hibernate.auditing.model.teneoauditing.TeneoAuditEntry; import org.hibernate.Query; import org.hibernate.ScrollMode; import org.hibernate.ScrollableResults; import org.hibernate.Session; import java.io.Serializable; import java.lang.reflect.Array; /** * Implements server side HQL query execution.. * * @author Martin Taal */ public class HibernateQueryHandler implements IQueryHandler { private HibernateStoreAccessor hibernateStoreAccessor; private HibernateAuditHandler hibernateAuditHandler; /** * Executes hql queries. Gets the session from the {@link HibernateStoreAccessor} creates a hibernate query and sets * the parameters taken from the {@link CDOQueryInfo#getParameters()}. Takes into account the * {@link CDOQueryInfo#getMaxResults()} and the {@link IHibernateStore#FIRST_RESULT} values for paging. * * @param info * the object containing the query and parameters * @param context * the query results are placed in the context * @see IQueryHandler#executeQuery(CDOQueryInfo, IQueryContext) */ public void executeQuery(CDOQueryInfo info, IQueryContext context) { // get a transaction, the hibernateStoreAccessor is placed in a threadlocal // so all db access uses the same session. final Session session = hibernateStoreAccessor.getHibernateSession(); try { // create the query final Query query = session.createQuery(info.getQueryString()); query.setReadOnly(true); // get the parameters with some parameter conversion int firstResult = -1; boolean cacheResults = true; for (String key : info.getParameters().keySet()) { if (key.compareToIgnoreCase(IHibernateStore.CACHE_RESULTS) == 0) { try { cacheResults = (Boolean) info.getParameters().get(key); } catch (ClassCastException e) { throw new IllegalArgumentException("Parameter " + IHibernateStore.CACHE_RESULTS //$NON-NLS-1$ + " must be a boolean. errorMessage " + e.getMessage()); } } else if (key.compareToIgnoreCase(IHibernateStore.FIRST_RESULT) == 0) { final Object o = info.getParameters().get(key); if (o != null) { try { firstResult = (Integer) o; } catch (ClassCastException e) { throw new IllegalArgumentException( "Parameter firstResult must be an integer but it is a " + o //$NON-NLS-1$ + " class " + o.getClass().getName()); //$NON-NLS-1$ } } } else { // in case the parameter is a CDOID get the object from the db final Object param = info.getParameters().get(key); if (param instanceof CDOID && HibernateUtil.getInstance().isStoreCreatedID((CDOID) param)) { final CDOID id = (CDOID) param; final String entityName = HibernateUtil.getInstance().getEntityName(id); final Serializable idValue = HibernateUtil.getInstance().getIdValue(id); final CDORevision revision = (CDORevision) session.get(entityName, idValue); query.setEntity(key, revision); if (cacheResults) { addToRevisionCache(revision); } } else { query.setParameter(key, param); } } } // set the first result if (firstResult > -1) { query.setFirstResult(firstResult); } // the max result if (info.getMaxResults() != CDOQueryInfo.UNLIMITED_RESULTS) { query.setMaxResults(info.getMaxResults()); } final ScrollableResults scroller = query.scroll(ScrollMode.FORWARD_ONLY); // and go for the query // future extension: support iterate, scroll through a parameter int i = 0; try { while (scroller.next()) { Object[] os = scroller.get(); Object o; if (os.length == 1) { o = handleAuditEntries(os[0]); } else { o = handleAuditEntries(os); } final boolean addOneMore = context.addResult(o); if (cacheResults && o instanceof CDORevision) { addToRevisionCache((CDORevision) o); } if (o instanceof InternalCDORevision) { ((InternalCDORevision) o).freeze(); } // clear the session every 1000 results or so if (i++ % 1000 == 0) { session.clear(); } if (!addOneMore) { return; } } } finally { scroller.close(); } } finally { session.close(); } } private Object handleAuditEntries(Object o) { if (o.getClass().isArray()) { for (int i = 0; i < Array.getLength(o); i++) { Array.set(o, i, handleAuditEntry(Array.get(o, i))); } return o; } return handleAuditEntry(o); } private Object handleAuditEntry(Object o) { if (!(o instanceof TeneoAuditEntry)) { // repair revision numbers if (o instanceof InternalCDORevision && hibernateStoreAccessor.getStore().isAuditing()) { final InternalCDORevision internalCDORevision = (InternalCDORevision) o; // a later revision, get the previous revision if (internalCDORevision.getVersion() > 1) { final CDORevision previousVersion = getPreviousRevision(internalCDORevision); if (previousVersion != null) { internalCDORevision.setBranchPoint(hibernateStoreAccessor.getStore().getMainBranchHead() .getBranch().getPoint(1 + previousVersion.getRevised())); } } } return o; } return hibernateAuditHandler.convertAuditEntryToCDORevision((TeneoAuditEntry) o); } private CDORevision getPreviousRevision(InternalCDORevision internalCDORevision) { final InternalCDORevisionManager cdoRevisionManager = hibernateStoreAccessor.getStore().getRepository() .getRevisionManager(); final CDOBranchVersion cdoBranchVersion = new CDOBranchVersionImpl( hibernateStoreAccessor.getStore().getMainBranchHead().getBranch(), internalCDORevision.getVersion() - 1); if (cdoRevisionManager.containsRevisionByVersion(internalCDORevision.getID(), cdoBranchVersion)) { return cdoRevisionManager.getRevisionByVersion(internalCDORevision.getID(), cdoBranchVersion, -1, true); } return hibernateStoreAccessor.readRevisionByVersion(internalCDORevision.getID(), cdoBranchVersion, -1, cdoRevisionManager); } private void addToRevisionCache(CDORevision revision) { final InternalCDORevision internalRevision = (InternalCDORevision) revision; for (EStructuralFeature feature : revision.getEClass().getEAllStructuralFeatures()) { if (!isMappedFeature(internalRevision, feature)) { continue; } if (feature.isMany() || feature instanceof EReference) { final Object value = internalRevision.getValue(feature); if (value instanceof WrappedHibernateList) { // force the size to be cached ((WrappedHibernateList) value).size(); } } } hibernateStoreAccessor.addToRevisionCache(revision); } private boolean isMappedFeature(InternalCDORevision revision, EStructuralFeature feature) { try { int featureID = revision.getClassInfo().getEClass().getFeatureID(feature); revision.getClassInfo().getPersistentFeatureIndex(featureID); return true; } catch (IllegalArgumentException ex) { return false; } catch (ArrayIndexOutOfBoundsException ex) { return false; } } public HibernateStoreAccessor getHibernateStoreAccessor() { return hibernateStoreAccessor; } public void setHibernateStoreAccessor(HibernateStoreAccessor hibernateStoreAccessor) { this.hibernateStoreAccessor = hibernateStoreAccessor; hibernateAuditHandler = hibernateStoreAccessor.getStore().getHibernateAuditHandler(); } }