com.mysema.query.group.GroupByProjection Maven / Gradle / Ivy
/*
* Copyright 2011, Mysema Ltd
*
* 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.mysema.query.group;
import java.util.LinkedHashMap;
import java.util.Map;
import com.mysema.query.types.Expression;
/**
* GroupByProjection provides projection of the Group results via the transform template method
*
* @author tiwe
*
* @param
* @param
*/
public abstract class GroupByProjection extends GroupByMap {
public GroupByProjection(Expression key, Expression... expressions) {
super(key, expressions);
}
@Override
protected Map transform(Map groups) {
Map results = new LinkedHashMap((int) Math.ceil(groups.size()/0.75), 0.75f);
for (Map.Entry entry : groups.entrySet()) {
results.put(entry.getKey(), transform(entry.getValue()));
}
return results;
}
/**
* Creates a result object from the given group
*
* @param group
* @return
*/
protected abstract V transform(Group group);
}