我正在尝试将GZip压缩用于自托管WCF服务。
SOAP 1.1是必需的。
我从下一个示例http://msdn.microsoft.com/en-us/library/cc138373.aspx实现了自定义MessageEncoder。
消息编码器已合并到新的自定义绑定中：
readonly HttpTransportBindingElement httpTransport;
readonly TextMessageEncodingBindingElement textMessageEncoding;
readonly CompressionMessageEncodingBindingElement compressionMessageEncoding;
public InsecureGZipBasicHttpBinding()
{
httpTransport = new AutoSecuredHttpTransportElement();
textMessageEncoding = new TextMessageEncodingBindingElement { MessageVersion = **MessageVersion.Soap11** };
compressionMessageEncoding = new CompressionMessageEncodingBindingElement(textMessageEncoding);
}
public override IChannelFactory<TChannel> BuildChannelFactory<TChannel>(BindingParameterCollection parameters)
{
return base.BuildChannelFactory<TChannel>(parameters);
}
public override BindingElementCollection CreateBindingElements()
{
var elements = new BindingElementCollection {
compressionMessageEncoding,
httpTransport
};
return elements;
}
下一个代码中的问题：
public override ArraySegment<byte> WriteMessage(Message message, int maxMessageSize, BufferManager bufferManager, int messageOffset)
{
var buffer = innerEncoder.WriteMessage(message, maxMessageSize, bufferManager, messageOffset);
var compressedBuffer = CompressBuffer(buffer, bufferManager, messageOffset);
return compressedBuffer;
}
每次到达时，消息都有SOAP 1.2版本，并且内部编码器无法处理。
如何将默认消息版本设置为SOAP 1.1？
答案 0 :(得分：1)
绑定的消息版本基本上由消息编码器定义，因此如果编码器实现本身正确地返回它，则不应该看到任何错误版本的消息到达编码器。我从下面显示的代码中的示例中逐字获取了GZip编码器的代码，它运行得很好。看看下面的代码，与你的代码进行比较，它应该给你一些关于它可以修复的提示。
public class StackOverflow_6986346
{
#region Code from the sample, verbatim
// This is constants for GZip message encoding policy.
static class GZipMessageEncodingPolicyConstants
{
public const string GZipEncodingName = "GZipEncoding";
public const string GZipEncodingNamespace = "http://schemas.microsoft.com/ws/06/2004/mspolicy/netgzip1";
public const string GZipEncodingPrefix = "gzip";
}
//This is the binding element that, when plugged into a custom binding, will enable the GZip encoder
public sealed class GZipMessageEncodingBindingElement
: MessageEncodingBindingElement //BindingElement
, IPolicyExportExtension
{
//We will use an inner binding element to store information required for the inner encoder
MessageEncodingBindingElement innerBindingElement;
//By default, use the default text encoder as the inner encoder
public GZipMessageEncodingBindingElement()
: this(new TextMessageEncodingBindingElement()) { }
public GZipMessageEncodingBindingElement(MessageEncodingBindingElement messageEncoderBindingElement)
{
this.innerBindingElement = messageEncoderBindingElement;
}
public MessageEncodingBindingElement InnerMessageEncodingBindingElement
{
get { return innerBindingElement; }
set { innerBindingElement = value; }
}
//Main entry point into the encoder binding element. Called by WCF to get the factory that will create the
//message encoder
public override MessageEncoderFactory CreateMessageEncoderFactory()
{
return new GZipMessageEncoderFactory(innerBindingElement.CreateMessageEncoderFactory());
}
public override MessageVersion MessageVersion
{
get { return innerBindingElement.MessageVersion; }
set { innerBindingElement.MessageVersion = value; }
}
public override BindingElement Clone()
{
return new GZipMessageEncodingBindingElement(this.innerBindingElement);
}
public override T GetProperty<T>(BindingContext context)
{
if (typeof(T) == typeof(XmlDictionaryReaderQuotas))
{
return innerBindingElement.GetProperty<T>(context);
}
else
{
return base.GetProperty<T>(context);
}
}
public override IChannelFactory<TChannel> BuildChannelFactory<TChannel>(BindingContext context)
{
if (context == null)
throw new ArgumentNullException("context");
context.BindingParameters.Add(this);
return context.BuildInnerChannelFactory<TChannel>();
}
public override IChannelListener<TChannel> BuildChannelListener<TChannel>(BindingContext context)
{
if (context == null)
throw new ArgumentNullException("context");
context.BindingParameters.Add(this);
return context.BuildInnerChannelListener<TChannel>();
}
public override bool CanBuildChannelListener<TChannel>(BindingContext context)
{
if (context == null)
throw new ArgumentNullException("context");
context.BindingParameters.Add(this);
return context.CanBuildInnerChannelListener<TChannel>();
}
void IPolicyExportExtension.ExportPolicy(MetadataExporter exporter, PolicyConversionContext policyContext)
{
if (policyContext == null)
{
throw new ArgumentNullException("policyContext");
}
XmlDocument document = new XmlDocument();
policyContext.GetBindingAssertions().Add(document.CreateElement(
GZipMessageEncodingPolicyConstants.GZipEncodingPrefix,
GZipMessageEncodingPolicyConstants.GZipEncodingName,
GZipMessageEncodingPolicyConstants.GZipEncodingNamespace));
}
}
//This class is used to create the custom encoder (GZipMessageEncoder)
internal class GZipMessageEncoderFactory : MessageEncoderFactory
{
MessageEncoder encoder;
//The GZip encoder wraps an inner encoder
//We require a factory to be passed in that will create this inner encoder
public GZipMessageEncoderFactory(MessageEncoderFactory messageEncoderFactory)
{
if (messageEncoderFactory == null)
throw new ArgumentNullException("messageEncoderFactory", "A valid message encoder factory must be passed to the GZipEncoder");
encoder = new GZipMessageEncoder(messageEncoderFactory.Encoder);
}
//The service framework uses this property to obtain an encoder from this encoder factory
public override MessageEncoder Encoder
{
get { return encoder; }
}
public override MessageVersion MessageVersion
{
get { return encoder.MessageVersion; }
}
//This is the actual GZip encoder
class GZipMessageEncoder : MessageEncoder
{
static string GZipContentType = "application/x-gzip";
//This implementation wraps an inner encoder that actually converts a WCF Message
//into textual XML, binary XML or some other format. This implementation then compresses the results.
//The opposite happens when reading messages.
//This member stores this inner encoder.
MessageEncoder innerEncoder;
//We require an inner encoder to be supplied (see comment above)
internal GZipMessageEncoder(MessageEncoder messageEncoder)
: base()
{
if (messageEncoder == null)
throw new ArgumentNullException("messageEncoder", "A valid message encoder must be passed to the GZipEncoder");
innerEncoder = messageEncoder;
}
public override string ContentType
{
get { return GZipContentType; }
}
public override string MediaType
{
get { return GZipContentType; }
}
//SOAP version to use - we delegate to the inner encoder for this
public override MessageVersion MessageVersion
{
get { return innerEncoder.MessageVersion; }
}
//Helper method to compress an array of bytes
static ArraySegment<byte> CompressBuffer(ArraySegment<byte> buffer, BufferManager bufferManager, int messageOffset)
{
MemoryStream memoryStream = new MemoryStream();
using (GZipStream gzStream = new GZipStream(memoryStream, CompressionMode.Compress, true))
{
gzStream.Write(buffer.Array, buffer.Offset, buffer.Count);
}
byte[] compressedBytes = memoryStream.ToArray();
int totalLength = messageOffset + compressedBytes.Length;
byte[] bufferedBytes = bufferManager.TakeBuffer(totalLength);
Array.Copy(compressedBytes, 0, bufferedBytes, messageOffset, compressedBytes.Length);
bufferManager.ReturnBuffer(buffer.Array);
ArraySegment<byte> byteArray = new ArraySegment<byte>(bufferedBytes, messageOffset, bufferedBytes.Length - messageOffset);
return byteArray;
}
//Helper method to decompress an array of bytes
static ArraySegment<byte> DecompressBuffer(ArraySegment<byte> buffer, BufferManager bufferManager)
{
MemoryStream memoryStream = new MemoryStream(buffer.Array, buffer.Offset, buffer.Count);
MemoryStream decompressedStream = new MemoryStream();
int totalRead = 0;
int blockSize = 1024;
byte[] tempBuffer = bufferManager.TakeBuffer(blockSize);
using (GZipStream gzStream = new GZipStream(memoryStream, CompressionMode.Decompress))
{
while (true)
{
int bytesRead = gzStream.Read(tempBuffer, 0, blockSize);
if (bytesRead == 0)
break;
decompressedStream.Write(tempBuffer, 0, bytesRead);
totalRead += bytesRead;
}
}
bufferManager.ReturnBuffer(tempBuffer);
byte[] decompressedBytes = decompressedStream.ToArray();
byte[] bufferManagerBuffer = bufferManager.TakeBuffer(decompressedBytes.Length + buffer.Offset);
Array.Copy(buffer.Array, 0, bufferManagerBuffer, 0, buffer.Offset);
Array.Copy(decompressedBytes, 0, bufferManagerBuffer, buffer.Offset, decompressedBytes.Length);
ArraySegment<byte> byteArray = new ArraySegment<byte>(bufferManagerBuffer, buffer.Offset, decompressedBytes.Length);
bufferManager.ReturnBuffer(buffer.Array);
return byteArray;
}
//One of the two main entry points into the encoder. Called by WCF to decode a buffered byte array into a Message.
public override Message ReadMessage(ArraySegment<byte> buffer, BufferManager bufferManager, string contentType)
{
//Decompress the buffer
ArraySegment<byte> decompressedBuffer = DecompressBuffer(buffer, bufferManager);
//Use the inner encoder to decode the decompressed buffer
Message returnMessage = innerEncoder.ReadMessage(decompressedBuffer, bufferManager);
returnMessage.Properties.Encoder = this;
return returnMessage;
}
//One of the two main entry points into the encoder. Called by WCF to encode a Message into a buffered byte array.
public override ArraySegment<byte> WriteMessage(Message message, int maxMessageSize, BufferManager bufferManager, int messageOffset)
{
//Use the inner encoder to encode a Message into a buffered byte array
ArraySegment<byte> buffer = innerEncoder.WriteMessage(message, maxMessageSize, bufferManager, 0);
//Compress the resulting byte array
return CompressBuffer(buffer, bufferManager, messageOffset);
}
public override Message ReadMessage(System.IO.Stream stream, int maxSizeOfHeaders, string contentType)
{
//Pass false for the "leaveOpen" parameter to the GZipStream constructor.
//This will ensure that the inner stream gets closed when the message gets closed, which
//will ensure that resources are available for reuse/release.
GZipStream gzStream = new GZipStream(stream, CompressionMode.Decompress, false);
return innerEncoder.ReadMessage(gzStream, maxSizeOfHeaders);
}
public override void WriteMessage(Message message, System.IO.Stream stream)
{
using (GZipStream gzStream = new GZipStream(stream, CompressionMode.Compress, true))
{
innerEncoder.WriteMessage(message, gzStream);
}
// innerEncoder.WriteMessage(message, gzStream) depends on that it can flush data by flushing
// the stream passed in, but the implementation of GZipStream.Flush will not flush underlying
// stream, so we need to flush here.
stream.Flush();
}
}
}
#endregion
public class InsecureGZipBasicHttpBinding : Binding
{
readonly HttpTransportBindingElement httpTransport;
readonly TextMessageEncodingBindingElement textMessageEncoding;
readonly GZipMessageEncodingBindingElement compressionMessageEncoding;
public InsecureGZipBasicHttpBinding()
{
httpTransport = new HttpTransportBindingElement();
textMessageEncoding = new TextMessageEncodingBindingElement { MessageVersion = MessageVersion.Soap11 };
compressionMessageEncoding = new GZipMessageEncodingBindingElement(textMessageEncoding);
}
public override BindingElementCollection CreateBindingElements()
{
return new BindingElementCollection
{
this.compressionMessageEncoding,
this.httpTransport
};
}
public override string Scheme
{
get { return this.httpTransport.Scheme; }
}
}
[ServiceContract]
public interface ITest
{
[OperationContract]
string Echo(string text);
}
public class Service : ITest
{
public string Echo(string text)
{
return text;
}
}
public static void Test()
{
string baseAddress = "http://" + Environment.MachineName + ":8000/Service";
ServiceHost host = new ServiceHost(typeof(Service), new Uri(baseAddress));
host.AddServiceEndpoint(typeof(ITest), new InsecureGZipBasicHttpBinding(), "");
host.Open();
Console.WriteLine("Host opened");
ChannelFactory<ITest> factory = new ChannelFactory<ITest>(new InsecureGZipBasicHttpBinding(), new EndpointAddress(baseAddress));
ITest proxy = factory.CreateChannel();
Console.WriteLine(proxy.Echo("Hello"));
((IClientChannel)proxy).Close();
factory.Close();
Console.Write("Press ENTER to close the host");
Console.ReadLine();
host.Close();
}
}