/src/com/google/appengine/datanucleus/PojoDatastoreBridge.java
Java | 103 lines | 66 code | 14 blank | 23 comment | 1 complexity | 9cdb25b0cf1ea5b892ded002ca553177 MD5 | raw file
Possible License(s): Apache-2.0
- /*
- * 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 org.datanucleus.ClassLoaderResolver;
- import org.datanucleus.ExecutionContext;
- import org.datanucleus.store.StoreManager;
- import org.datanucleus.store.connection.ManagedConnection;
- import org.datanucleus.store.connection.ManagedConnectionResourceListener;
- import org.datanucleus.metadata.AbstractClassMetaData;
- import com.google.appengine.datanucleus.query.DatastoreQuery;
- import org.datanucleus.store.query.AbstractJavaQuery;
- import org.datanucleus.store.query.AbstractQueryResult;
- import java.util.List;
- import java.util.Map;
- /**
- * Utilities for converting between the low-level datastore api and pojos.
- *
- * @author Max Ross <max.ross@gmail.com>
- */
- class PojoDatastoreBridge {
- <T> List<T> toPojoResult(final ExecutionContext ec, Class<T> cls, Iterable<Entity> queryResultIterable, Cursor endCursor) {
- final ClassLoaderResolver clr = ec.getClassLoaderResolver();
- final AbstractClassMetaData acmd = ec.getMetaDataManager().getMetaDataForClass(cls, clr);
- Utils.Function<Entity, Object> func = new Utils.Function<Entity, Object>() {
- public Object apply(Entity from) {
- return EntityUtils.entityToPojo(from, acmd, clr, ec, true, ec.getFetchPlan().getCopy());
- }
- };
- AbstractJavaQuery query = new DummyQuery(ec.getStoreManager(), ec);
- final ManagedConnection mconn = ec.getStoreManager().getConnection(ec);
- try {
- List<T> results = (List<T>) DatastoreQuery.newStreamingQueryResultForEntities(
- queryResultIterable, func, endCursor, query);
- if (results instanceof AbstractQueryResult) {
- // Lazy loading results : add listener to the connection so we can get a callback when the connection is flushed.
- final AbstractQueryResult qr = (AbstractQueryResult)results;
- ManagedConnectionResourceListener listener = new ManagedConnectionResourceListener() {
- public void managedConnectionPreClose() {
- // Disconnect the query from this ManagedConnection (read in unread rows etc)
- qr.disconnect();
- }
- public void managedConnectionPostClose() {}
- public void resourcePostClose() {
- mconn.removeListener(this);
- }
- public void transactionFlushed() {}
- public void transactionPreClose() {
- // Disconnect the query from this ManagedConnection (read in unread rows etc)
- qr.disconnect();
- }
- };
- mconn.addListener(listener);
- qr.addConnectionListener(listener);
- }
- return results;
- } finally {
- mconn.release();
- }
- }
- private static final class DummyQuery extends AbstractJavaQuery {
- private DummyQuery(StoreManager storeMgr, ExecutionContext ec) {
- super(storeMgr, ec);
- }
- public String getSingleStringQuery() {
- throw new UnsupportedOperationException();
- }
- protected void compileInternal(Map parameterValues) {
- throw new UnsupportedOperationException();
- }
- protected Object performExecute(Map parameters) {
- throw new UnsupportedOperationException();
- }
- }
- }