#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
using System;
using System.Collections;
using Spring.Messaging.Ems.Common;
using TIBCO.EMS;
namespace Spring.Messaging.Ems.Support.Converter{
/// <summary> A simple message converter that can handle TextMessages, BytesMessages,
/// MapMessages, and ObjectMessages. Used as default by EmsTemplate, for
/// <code>ConvertAndSend</code> and <code>ReceiveAndConvert</code> operations.
///
/// <p>Converts a String to a EMS TextMessage, a byte array to a EMS BytesMessage,
/// a Map to a EMS MapMessage, and a Serializable object to a EMS ObjectMessage
/// (or vice versa).</p>
///
///
/// </summary>
/// <author>Juergen Hoeller</author>
/// <author>Mark Pollack (.NET)</author>
public class SimpleMessageConverter : IMessageConverter
{
/// <summary> Convert a .NET object to a EMS Message using the supplied session
/// to create the message object.
/// </summary>
/// <param name="objectToConvert">the object to convert
/// </param>
/// <param name="session">the Session to use for creating a EMS Message
/// </param>
/// <returns> the EMS Message
/// </returns>
/// <throws>EMSException if thrown by EMS API methods </throws>
/// <throws>MessageConversionException in case of conversion failure </throws>
public Message ToMessage(object objectToConvert, ISession session)
{
if (objectToConvert is Message)
{
return (Message) objectToConvert;
}
if (objectToConvert is string)
{
return CreateMessageForString((string) objectToConvert, session);
}
if (objectToConvert is sbyte[])
{
return CreateMessageForByteArray((byte[]) objectToConvert, session);
}
if (objectToConvert is IDictionary)
{
return CreateMessageForMap((IDictionary) objectToConvert, session);
}
if (objectToConvert != null && objectToConvert.GetType().IsSerializable)
{
return CreateMessageForSerializable(objectToConvert, session);
}
throw new MessageConversionException("Cannot convert object [" + objectToConvert + "] to EMS message");
}
/// <summary> Convert from a EMS Message to a .NET object.</summary>
/// <param name="messageToConvert">the message to convert
/// </param>
/// <returns> the converted .NET object
/// </returns>
/// <throws>MessageConversionException in case of conversion failure </throws>
public object FromMessage(Message messageToConvert)
{
if (messageToConvert is TextMessage)
{
return ExtractStringFromMessage((TextMessage) messageToConvert);
}
if (messageToConvert is BytesMessage)
{
return ExtractByteArrayFromMessage((BytesMessage) messageToConvert);
}
if (messageToConvert is MapMessage)
{
return ExtractMapFromMessage((MapMessage) messageToConvert);
}
if (messageToConvert is ObjectMessage)
{
return ExtractSerializableFromMessage((ObjectMessage) messageToConvert);
}
return messageToConvert;
}
#region To Converter Methods
/// <summary> Create a EMS TextMessage for the given String.</summary>
/// <param name="text">the String to convert
/// </param>
/// <param name="session">current EMS session
/// </param>
/// <returns> the resulting message
/// </returns>
/// <throws> EMSException if thrown by EMS methods </throws>
protected virtual TextMessage CreateMessageForString(string text, ISession session)
{
return session.CreateTextMessage((text));
}
/// <summary> Create a EMS BytesMessage for the given byte array.</summary>
/// <param name="bytes">the byyte array to convert
/// </param>
/// <param name="session">current EMS session
/// </param>
/// <returns> the resulting message
/// </returns>
/// <throws> EMSException if thrown by EMS methods </throws>
protected virtual BytesMessage CreateMessageForByteArray(byte[] bytes, ISession session)
{
BytesMessage message = session.CreateBytesMessage();
message.WriteBytes(bytes);
return message;
}
/// <summary> Create a EMS MapMessage for the given Map.</summary>
/// <param name="map">the Map to convert
/// </param>
/// <param name="session">current EMS session
/// </param>
/// <returns> the resulting message
/// </returns>
/// <throws> EMSException if thrown by EMS methods </throws>
protected virtual MapMessage CreateMessageForMap(IDictionary map, ISession session)
{
MapMessage mapMessage = session.CreateMapMessage();
foreach (DictionaryEntry entry in map)
{
if (!(entry.Key is string))
{
throw new MessageConversionException("Cannot convert non-String key of type [" +
(entry.Key != null ? entry.Key.GetType().FullName : null) +
"] to MapMessage entry");
}
mapMessage.SetObject(entry.Key.ToString(), entry.Value);
}
return mapMessage;
}
/// <summary> Create a EMS ObjectMessage for the given Serializable object.</summary>
/// <param name="objectToSend">the Serializable object to convert
/// </param>
/// <param name="session">current EMS session
/// </param>
/// <returns> the resulting message
/// </returns>
/// <throws> EMSException if thrown by EMS methods </throws>
protected virtual ObjectMessage CreateMessageForSerializable(
object objectToSend, ISession session)
{
return session.CreateObjectMessage(objectToSend);
}
#endregion
#region From Converter Mehtods
/// <summary> Extract a String from the given TextMessage.</summary>
/// <param name="message">the message to convert
/// </param>
/// <returns> the resulting String
/// </returns>
/// <throws> EMSException if thrown by EMS methods </throws>
protected virtual string ExtractStringFromMessage(TextMessage message)
{
return message.Text;
}
/// <summary> Extract a byte array from the given BytesMessage.</summary>
/// <param name="message">the message to convert
/// </param>
/// <returns> the resulting byte array
/// </returns>
/// <throws> EMSException if thrown by EMS methods </throws>
protected virtual byte[] ExtractByteArrayFromMessage(BytesMessage message)
{
byte[] bytes = new byte[(int)message.BodyLength];
message.ReadBytes(bytes);
return bytes;
}
/// <summary> Extract a IDictionary from the given MapMessage.</summary>
/// <param name="message">the message to convert
/// </param>
/// <returns> the resulting Map
/// </returns>
/// <throws>EMSException if thrown by EMS methods </throws>
protected virtual IDictionary ExtractMapFromMessage(MapMessage message)
{
IDictionary dictionary = new Hashtable();
IEnumerator e = message.MapNames;
while (e.MoveNext())
{
String key = (String)e.Current;
dictionary.Add(key, message.GetObject(key));
}
return dictionary;
}
/// <summary>
/// Extracts the serializable object from the given object message.
/// </summary>
/// <param name="message">The message to convert.</param>
/// <returns>The resulting serializable object.</returns>
protected virtual object ExtractSerializableFromMessage(
ObjectMessage message)
{
return message.TheObject;
}
#endregion
}
}
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