/*
* Copyright (C) 2010 Google Inc
*
* Licensed 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 com.google.appengine.datanucleus;
import com.google.appengine.api.datastore.Cursor;
import com.google.appengine.api.datastore.Entity;
import com.google.appengine.api.datastore.FetchOptions;
import com.google.appengine.api.datastore.Key;
import com.google.appengine.api.datastore.PreparedQuery;
import com.google.appengine.api.datastore.QueryResultIterable;
import com.google.appengine.api.datastore.QueryResultList;
import org.datanucleus.ClassLoaderResolver;
import org.datanucleus.api.jdo.JDOPersistenceManager;
import org.datanucleus.metadata.AbstractClassMetaData;
import org.datanucleus.ExecutionContext;
import org.datanucleus.state.ObjectProvider;
import java.util.List;
import javax.jdo.PersistenceManager;
/**
* Utilities for converting between the low-level datastore api and JDO.<br>
* This class is part of the public api of the DataNucleus App Engine plugin and can be safely used.
*
* @author Max Ross <max.ross@gmail.com>
*/
public final class JDODatastoreBridge extends PojoDatastoreBridge {
/**
* Convert the result of a low-level datastore query into a List of JDO entities.
*
* @param pm The PersistenceManager with which the conversion results will be associated.
* @param cls The type of object to which the {@link Entity Entities} in the result list should be converted.
* @param queryResultList The result of the low-level datastore query.
* @return The {@link Entity Entities} in the provided result list, converted to JDO entities.
*
* @see PreparedQuery#asQueryResultList(FetchOptions)
*/
public <T> List<T> toJDOResult(PersistenceManager pm, Class<T> cls, QueryResultList<Entity> queryResultList) {
return toJDOResult(pm, cls, queryResultList, queryResultList.getCursor());
}
/**
* Convert the result of a low-level datastore query into a List of JDO entities.
*
* @param pm The PersistenceManager with which the conversion results will be associated.
* @param cls The type of object to which the {@link Entity Entities} in the
* result iterable should be converted.
* @param queryResultIterable The result of the low-level datastore query.
* @return The {@link Entity Entities} in the provided result iterable, converted to JDO entities.
*
* @see PreparedQuery#asQueryResultIterable()
*/
public <T> List<T> toJDOResult(PersistenceManager pm, Class<T> cls, QueryResultIterable<Entity> queryResultIterable) {
return toJDOResult(pm, cls, queryResultIterable, null);
}
private <T> List<T> toJDOResult(PersistenceManager pm, Class<T> cls, Iterable<Entity> queryResultIterable, Cursor endCursor) {
ExecutionContext ec = ((JDOPersistenceManager) pm).getExecutionContext();
return toPojoResult(ec, cls, queryResultIterable, endCursor);
}
/**
* Convenience method to return the Entity for this <b>managed</b> JDO object.
* @param pc The JDO object (managed by the provided PM)
* @param pm The Persistence Manager
* @return The Entity (if accessible)
*/
public Entity getEntityFromJDO(Object pc, PersistenceManager pm) {
ExecutionContext ec = ((JDOPersistenceManager)pm).getExecutionContext();
ObjectProvider op = ec.findObjectProvider(pc);
if (op != null) {
DatastoreManager storeMgr = (DatastoreManager) ec.getStoreManager();
DatastoreTransaction txn = storeMgr.getDatastoreTransaction(ec);
if (txn != null) {
Entity entity = (Entity)op.getAssociatedValue(txn);
if (entity != null) {
return entity;
} else {
Key key = EntityUtils.getPkAsKey(op);
return EntityUtils.getEntityFromDatastore(storeMgr.getDatastoreServiceForReads(ec), op, key);
}
} else {
Key key = EntityUtils.getPkAsKey(op);
return EntityUtils.getEntityFromDatastore(storeMgr.getDatastoreServiceForReads(ec), op, key);
}
} else {
// TODO Cater for detached objects
throw new UnsupportedOperationException("Not yet supported getting Entity for detached/unmanaged object");
}
}
/**
* Convenience method to return a managed (POJO) object for the provided Entity for the PersistenceManager.
* @param entity The entity
* @param pm The PersistenceManager
* @param cls The POJO class being represented here
* @return The POJO
*/
public Object getJDOFromEntity(Entity entity, PersistenceManager pm, Class cls) {
ExecutionContext ec = ((JDOPersistenceManager)pm).getExecutionContext();
ClassLoaderResolver clr = ec.getClassLoaderResolver();
AbstractClassMetaData cmd = ec.getMetaDataManager().getMetaDataForClass(cls, clr);
return EntityUtils.entityToPojo(entity, cmd, clr, ec, false, ec.getFetchPlan());
}
}