com.mysema.query.group.Group 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.List;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Set;
import com.mysema.query.types.Expression;
/**
* A group of rows. Group is build according to GroupDefinitions.
*
* @author sasa
*
*/
public interface Group {
/**
* @return Groups elements as an array
*/
Object[] toArray();
/**
* Returns the value of the given group.
*
* @param Type of element in a single ResultSet row, i.e. type of {@code Expression}
* @param Target type of this group, e.g. {@code List}
* @param coldef
* @throws NoSuchElementException if group is undefined.
* @throws ClassCastException if group is of different type
* @return Value of given group definition in this group
*/
R getGroup(GroupExpression coldef);
/**
* Returns the value of the given single valued expression. This is the
* first value of given column within this group of the ResultSet.
*
* @param Value type
* @param expr Grouped expression
* @throws NoSuchElementException if group is undefined.
* @throws ClassCastException if group is of different type (e.g. Set)
* @return Value of given expression in this group
*/
T getOne(Expression expr);
/**
* Returns a Set of values in this group.
*
* @param Value type of Set
* @param expr Grouped expression
* @throws NoSuchElementException if group is undefined.
* @throws ClassCastException if group is of different type (e.g. List)
* @return Set of values in this group
*/
Set getSet(Expression expr);
/**
* Returns a List of values in this group.
*
* @param Value type of List
* @param expr Grouped expression
* @throws NoSuchElementException if group is undefined.
* @throws ClassCastException if group is of different type (e.g. Set)
* @return List of values in this group
*/
List getList(Expression expr);
/**
* Returns a Map of values in this group
*
* @param Key type of result Map
* @param Value type of result Map
* @param key Key expression
* @param value Value expression
* @throws NoSuchElementException if group is undefined.
* @throws ClassCastException if group is of different type (e.g. List)
* @return Map of values in this group
*/
Map getMap(Expression key, Expression value);
}