org.apache.openjpa.kernel.exps.Count 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
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* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.openjpa.kernel.exps;
import java.util.Collection;
import java.util.Iterator;
import serp.util.Numbers;
/**
* Count non-null values.
*
* @author Abe White
*/
class Count
extends AggregateVal {
/**
* Constructor. Provide the value to count.
*/
public Count(Val val) {
super(val);
}
protected Class getType(Class c) {
return long.class;
}
protected Object operate(Collection os, Class c) {
long count = 0;
for (Iterator itr = os.iterator(); itr.hasNext();)
if (itr.next() != null)
count++;
return Numbers.valueOf(count);
}
}