org.apache.calcite.adapter.geode.simple.GeodeSimpleEnumerator Maven / Gradle / Ivy
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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to you 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 org.apache.calcite.adapter.geode.simple;
import org.apache.calcite.linq4j.Enumerator;
import org.apache.geode.cache.client.ClientCache;
import org.apache.geode.cache.query.QueryService;
import org.apache.geode.cache.query.SelectResults;
import java.util.Iterator;
/**
* Geode Simple Enumerator.
*
* @param Element type
*/
public abstract class GeodeSimpleEnumerator implements Enumerator {
private Iterator results;
private E current;
private ClientCache clientCache;
public GeodeSimpleEnumerator(ClientCache clientCache, String regionName) {
this.clientCache = clientCache;
QueryService queryService = clientCache.getQueryService();
String oql = "select * from /" + regionName.trim();
try {
results = ((SelectResults) queryService.newQuery(oql).execute()).iterator();
} catch (Exception e) {
e.printStackTrace();
results = null;
}
}
@Override public E current() {
return current;
}
@Override public boolean moveNext() {
if (results.hasNext()) {
current = convert(results.next());
return true;
}
current = null;
return false;
}
@Override public void reset() {
throw new UnsupportedOperationException();
}
@Override public void close() {
/*clientCache.close(); */
}
public abstract E convert(Object obj);
}
// End GeodeSimpleEnumerator.java