#region License
/*
* Copyright 2002-2005 the original author or authors.
*
* 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.
*/
#endregion
using System;
using System.Collections;
using Spring.Util;
namespace Spring.Expressions.Processors{
/// <summary>
/// Implementation of the sum aggregator.
/// </summary>
/// <author>Aleksandar Seovic</author>
public class SumAggregator : ICollectionProcessor
{
/// <summary>
/// Returns the sum of the numeric values in the source collection.
/// </summary>
/// <param name="source">
/// The source collection to process.
/// </param>
/// <param name="args">
/// Ignored.
/// </param>
/// <returns>
/// The sum of the numeric values in the source collection.
/// </returns>
public object Process(ICollection source, object[] args)
{
object total = 0d;
foreach (object item in source)
{
if (item != null)
{
if (NumberUtils.IsNumber(item))
{
total = NumberUtils.Add(total, item);
}
else
{
throw new ArgumentException("Sum can only be calculated for a collection of numeric values.");
}
}
}
return total;
}
}
}
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