3. Receiving Zipped Files
The reverse scenario to
sending ZIP files is receiving them. When receiving ZIP files, you will
need to create a Decoding component, which can extract the files inside
and submit them to the pipeline for further processing. This example
only addresses the simple example of a ZIP file containing one XML file
inside. The following example could be expanded upon to handle ZIP files
with multiple files inside and files of binary types.
using System;
using System.ComponentModel;
using System.Collections;
using System.Diagnostics;
using System.Drawing;
using System.IO;
using System.Reflection;
using Microsoft.BizTalk.Component.Interop;
using ICSharpCode.SharpZipLib.Zip;
namespace Probiztalk.Samples.PipelineComponents
{
[ComponentCategory(CategoryTypes.CATID_PipelineComponent)]
[ComponentCategory(CategoryTypes.CATID_Decoder)]
[System.Runtime.InteropServices.Guid("67C8CFB9-D89A-4415-A112-76187FC294D1")]
public class ZipDecodeComponent :
IBaseComponent,
Microsoft.BizTalk.Component.Interop.IComponent,
Microsoft.BizTalk.Component.Interop.IPersistPropertyBag
IComponentUI
{
// Component information
#region IBaseComponent
[Browsable(false)]
public string Name
{
get
{
return "ZIP decoder";
}
}
[Browsable(false)]
public string Version
{
get
{
return "1.0";
}
}
[Browsable(false)]
public string Description
{
get
{
return "Zip Decode Pipeline Component";
}
}
[Browsable(false)] public System.IntPtr Icon
{
get
{
return ((Bitmap)resourceManager.
GetObject("IconBitmap")).GetHicon();
}
}
#endregion
private System.Resources.ResourceManager resourceManager =
new System.Resources.ResourceManager(
"Probiztalk.Samples.PipelineComponents.ZipDecodeComponent",
Assembly.GetExecutingAssembly());
// Property: Password
private string _password;
[
DisplayName("Password"),
Description("Password used to unzip messages.")
]
public string Password
{
get { return _password; }
set { _password = value; }
}
private Stream Decode (Stream inStream)
{
Stream outStream = inStream;
string inFile = Path.GetTempFileName();
string outFile = Path.ChangeExtension(inFile, "txt");
try
{
ZipInputStream zipStream = new ZipInputStream( inStream );
// get password, if supplied
if ((_password != null) && (_password != ""))
zipStream.Password = _password;
// this algorithm demands that the zip
//archive contain exactly one file
ZipEntry entry = zipStream.GetNextEntry();
if (entry == null)
throw new ApplicationException(
@"Input ZIP archive does not contain any files -
expecting exactly one file" );
if (entry.IsDirectory)
throw new ApplicationException(
@"Input ZIP contains a directory -
expecting exactly one file" );
// copy the compressed stream into the output stream
outStream = new MemoryStream();
byte[] buffer = new byte[4096];
int count = 0;
while ((count = zipStream.Read(buffer, 0, buffer.Length)) != 0)
outStream.Write( buffer, 0, count );
// make sure that was the one and only file
entry = zipStream.GetNextEntry();
if (entry != null)
throw new ApplicationException(
@"Input ZIP archive contains multiple files
and/or directories - expecting exactly one file" );
zipStream.Close();
#if DEBUG
outStream.Seek( 0, SeekOrigin.Begin );
Probiztalk.Samples.PipelineUtilities.FileStreamReadWrite.
DumpStreamToFile( outStream, outFile );
#endif
outStream.Seek( 0, SeekOrigin.Begin );
}
catch (Exception ex)
{
System.Diagnostics.Debug.WriteLine(ex);
throw;
}
finally
{
if (File.Exists(inFile))
{
File.Delete(inFile);
}
if (File.Exists(outFile))
{
File.Delete(outFile);
}
}
return outStream;
}
#region IPersistPropertyBag Members
public void InitNew()
{
}
public void GetClassID(out Guid classID)
{
classID = new Guid ("19800584-283D-44da-B1EE-0968387DA088");
}
public void Load(IPropertyBag propertyBag, int errorLog)
{
string text;
text = (string)ReadPropertyBag( propertyBag, "Password" );
if (text != null) _password = text;
}
public void Save(IPropertyBag propertyBag, bool clearDirty,
bool saveAllProperties)
{
object val;
val = (object)_password;
WritePropertyBag( propertyBag, "Password", val );
}
#endregion
#region IComponent Members
public Microsoft.BizTalk.Message.Interop.IBaseMessage Execute(
IPipelineContext pContext,
Microsoft.BizTalk.Message.Interop.IBaseMessage pInMsg)
{
try
{
if (pInMsg != null)
{
Stream originalStream =
pInMsg.BodyPart.GetOriginalDataStream();
pInMsg.BodyPart.Data = Decode( originalStream );
pContext.ResourceTracker.AddResource( pInMsg.BodyPart.Data );
}
}
catch (Exception ex)
{
System.Diagnostics.Debug.WriteLine(
@"Exception caught in ZipDecodeComponent::Execute: " +
ex.Message );
throw new ApplicationException(
@"ZipDecodeComponent was unable to decompress
input stream. This may occur if there is more than one
file in the zip archive. See inner exception
for more information.", ex );
}
return pInMsg;
}
#endregion
#region IComponentUI Members
/// <summary>
/// The Validate method is called by the BizTalk Editor during the build
/// of a BizTalk project.
/// "<\summary>
/// <param name="obj">An Object containing the
/// configuration properties."<\param>
/// <returns>The IEnumerator enables the caller to enumerate through a
/// collection of strings containing error messages. These error messages
/// appear as compiler error messages. To report successful property
/// validation, the method should return an empty enumerator."<\returns>
public IEnumerator Validate(object projectSystem)
{
// example implementation:
// ArrayList errorList = new ArrayList();
// errorList.Add("This is a compiler error");
// return errorList.GetEnumerator();
return null;
}
#endregion
#region Utility functions
/// <summary>
/// Reads property value from property bag.
/// "<\summary>
/// <param name="pb">Property bag."<\param>
/// <param name="propName">Name of property."<\param>
/// <returns>Value of the property."<\returns>
public static object
ReadPropertyBag(Microsoft.BizTalk.Component.Interop.IPropertyBag pb,
string propName)
{
object val = null;
try
{
pb.Read(propName, out val, 0);
}
catch (ArgumentException)
{
return val;
}
catch (Exception ex)
{
throw new ApplicationException(ex.Message);
}
return val;
}
/// <summary>
/// Writes property values into a property bag.
/// "<\summary>
/// <param name="pb">Property bag."<\param>
/// <param name="propName">Name of property."<\param>
/// <param name="val">Value of property."<\param>
public static void WritePropertyBag(
Microsoft.BizTalk.Component.Interop.IPropertyBag pb,
string propName, object val)
{
try
{
pb.Write(propName, ref val);
}
catch (Exception ex)
{
throw new ApplicationException(ex.Message);
}
}
#endregion
}
}
