#region License
/*
* Copyright 2002-2006 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
#region Imports
using System;
using System.Collections;
using Spring.Collections;
using Spring.Data.Support;
#endregion
namespace Spring.Data.Core{
/// <summary>
/// Adapter implementation of the ResultSetExtractor interface that delegates
/// to a RowMapper which is supposed to create an object for each row.
/// Each object is added to the results List of this ResultSetExtractor.
/// </summary>
/// <remarks>
/// Useful for the typical case of one object per row in the database table.
/// The number of entries in the results list will match the number of rows.
/// <p>
/// Note that a RowMapper object is typically stateless and thus reusable;
/// just the RowMapperResultSetExtractor adapter is stateful.
/// </p>
/// <p>
/// As an alternative consider subclassing MappingAdoQuery from the
/// Spring.Data.Objects namespace: Instead of working with separate
/// AdoTemplate and IRowMapper objects you can have executable
/// query objects (containing row-mapping logic) there.
/// </p>
/// </remarks>
/// <author>Mark Pollack (.NET)</author>
public class RowMapperResultSetExtractor : IResultSetExtractor
{
#region Fields
private IRowMapper rowMapper;
private RowMapperDelegate rowMapperDelegate;
private int rowsExpected;
#endregion
#region Constructor (s)
/// <summary>
/// Initializes a new instance of the <see cref="RowMapperResultSetExtractor"/> class.
/// </summary>
public RowMapperResultSetExtractor(IRowMapper rowMapper) : this(rowMapper,0, null)
{
}
public RowMapperResultSetExtractor(IRowMapper rowMapper, int rowsExpected) : this(rowMapper, rowsExpected, null)
{
}
public RowMapperResultSetExtractor(IRowMapper rowMapper, int rowsExpected, IDataReaderWrapper dataReaderWrapper)
{
//TODO use datareaderwrapper
if (rowMapper == null)
{
throw new ArgumentNullException("rowMapper");
}
this.rowMapper = rowMapper;
this.rowsExpected = rowsExpected;
}
public RowMapperResultSetExtractor(RowMapperDelegate rowMapperDelegate)
: this(rowMapperDelegate, 0, null)
{
}
public RowMapperResultSetExtractor(RowMapperDelegate rowMapperDelegate, int rowsExpected)
: this(rowMapperDelegate, rowsExpected, null)
{
}
public RowMapperResultSetExtractor(RowMapperDelegate rowMapperDelegate, int rowsExpected, IDataReaderWrapper dataReaderWrapper)
{
//TODO use datareaderwrapper
if (rowMapperDelegate == null)
{
throw new ArgumentNullException("rowMapperDelegate");
}
this.rowMapperDelegate = rowMapperDelegate;
this.rowsExpected = rowsExpected;
}
#endregion
#region IResultSetExtractor Members
public object ExtractData(System.Data.IDataReader reader)
{
// Use the more efficient collection if we know how many rows to expect:
// ArrayList in case of a known row count, LinkedList if unknown
IList results = (rowsExpected > 0) ? (IList) new ArrayList(rowsExpected) : new LinkedList();
int rowNum = 0;
if (rowMapper != null)
{
while (reader.Read())
{
results.Add(rowMapper.MapRow(reader, rowNum++));
}
}
else
{
while (reader.Read())
{
results.Add(rowMapperDelegate(reader, rowNum++));
}
}
return results;
}
#endregion
}
}
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