Using a Dynamic URL to connect to a Java Web Service.

[JL]

I have a VB.NET desktop program that reads/writes data to a server
using a Java-based Web Service. This web service, in identical
formats, is located on several servers with each server being a
different customer and different data content.

To connect with the Java Web Service, I downloaded the WSDL file and
used wsdl.exe to create a .vb class file. In my program, I simply call
the functions of the class to communicate with the server.

For the different servers, I must download each WSDL separately, use
wsdl to create a .vb class for each server, and then compile a
different .exe for each server. I would like to be able to have one
..exe with the URL for the web service stored separately with the
program dynamically connecting to the appropriate web service.

The .vb class created by wsdl.exe contains the following Sub New that
runs when the web service is instantiated:

Public Sub New()
MyBase.New()
Me.Url = "http://www.url.com/cgi-bin/WebObjects/SCWebService.woa/1/ws/WSP"
End Sub

I can easily modify this dynamically. However, each function in the
web service is built something like this:

<System.Web.Services.Protocols.SoapRpcMethodAttrib ute("",
RequestNamespace:="http://www.url.com/cgi-bin/WebObjects/SCWebService.woa/1/ws/WSP",
ResponseNamespace:="http://www.url.com/cgi-bin/WebObjects/SCWebService.woa/1/ws/WSP")>
_
Public Function login(ByVal accessKey As String, ByVal email As
String, ByVal password As String) As
<System.Xml.Serialization.SoapElementAttribute("lo ginReturn")> String
Dim results() As Object = Me.Invoke("login", New Object()
{accessKey, email, password})
Return CType(results(0), String)
End Function
Public Function Beginlogin(ByVal accessKey As String, ByVal email As
String, ByVal password As String, ByVal callback As
System.AsyncCallback, ByVal asyncState As Object) As
System.IAsyncResult
Return Me.BeginInvoke("login", New Object() {accessKey, email,
password}, callback, asyncState)
End Function
Public Function Endlogin(ByVal asyncResult As System.IAsyncResult)
As String
Dim results() As Object = Me.EndInvoke(asyncResult)
Return CType(results(0), String)
End Function

As you can see, the URL is also contained in the function's initial
<system.web.services ...etc > tag. If I understand correctly, this is
something that is used when the program is compiled, not at run-time.
Therefore, this is not something that can be changed at run-time or
dynamically.

Any suggestions on how I can make this web service URL dynamic?

Many Thanks, John L.

[Dino Chiesa [Microsoft]]

> Any suggestions on how I can make this web service URL dynamic?

YES,
If the Java web service really is exactly the same on all the servers, then
it should use exactly the same WSDL on all those servers. The request and
response namespaces should not vary across different URLs. If you can get
that to happen, then all you need to change is the Url property on the web
service proxy.

Ignoring or over-riding this namespace would be subverting a key mechanism
for synchronizing and versioning services, interfaces, and request and
response messages. So I would advise against it. Instead, fix the
server-side implementation to be more sane..^H^H^H^H. er, ...more
reasonable.

-D
"JL" <jl*******@yahoo.com> wrote in message
news:ee**************************@posting.google.c om...

I have a VB.NET desktop program that reads/writes data to a server
using a Java-based Web Service. This web service, in identical
formats, is located on several servers with each server being a
different customer and different data content.

To connect with the Java Web Service, I downloaded the WSDL file and
used wsdl.exe to create a .vb class file. In my program, I simply call
the functions of the class to communicate with the server.

For the different servers, I must download each WSDL separately, use
wsdl to create a .vb class for each server, and then compile a
different .exe for each server. I would like to be able to have one
.exe with the URL for the web service stored separately with the
program dynamically connecting to the appropriate web service.

The .vb class created by wsdl.exe contains the following Sub New that
runs when the web service is instantiated:

Public Sub New()
MyBase.New()
Me.Url =
"http://www.url.com/cgi-bin/WebObjects/SCWebService.woa/1/ws/WSP"
End Sub

I can easily modify this dynamically. However, each function in the
web service is built something like this:

<System.Web.Services.Protocols.SoapRpcMethodAttrib ute("",
RequestNamespace:="http://www.url.com/cgi-bin/WebObjects/SCWebService.woa/1/ws/WSP",
ResponseNamespace:="http://www.url.com/cgi-bin/WebObjects/SCWebService.woa/1/ws/WSP")>
_
Public Function login(ByVal accessKey As String, ByVal email As
String, ByVal password As String) As
<System.Xml.Serialization.SoapElementAttribute("lo ginReturn")> String
Dim results() As Object = Me.Invoke("login", New Object()
{accessKey, email, password})
Return CType(results(0), String)
End Function
Public Function Beginlogin(ByVal accessKey As String, ByVal email As
String, ByVal password As String, ByVal callback As
System.AsyncCallback, ByVal asyncState As Object) As
System.IAsyncResult
Return Me.BeginInvoke("login", New Object() {accessKey, email,
password}, callback, asyncState)
End Function
Public Function Endlogin(ByVal asyncResult As System.IAsyncResult)
As String
Dim results() As Object = Me.EndInvoke(asyncResult)
Return CType(results(0), String)
End Function

As you can see, the URL is also contained in the function's initial
<system.web.services ...etc > tag. If I understand correctly, this is
something that is used when the program is compiled, not at run-time.
Therefore, this is not something that can be changed at run-time or
dynamically.

Any suggestions on how I can make this web service URL dynamic?

Many Thanks, John L.

[JL]

Dino. Thanks for your response and input.

The customer stated that the web service and wsdl on both servers were
the same. On visual inspection, the only differences are the different
URLs (that's expected) and some of the items are in a different order.

Using the VB module that was created for server1, I substitute server2
in the URL property. When calling a function, I get the following
error:

org.xml.sax.SAXException: Deserializing parameter 'wsUser': could not
find deserializer for type
{http://server1.com/cgi-bin/webobject/etc}WSUser.

While I am calling the webservice on server2, it appears that it is
going to server1 for deserializing information and is being rejected.

Any suggestions?

Thanks. John.
"Dino Chiesa [Microsoft]" <di****@online.microsoft.com> wrote in message news:<#R**************@TK2MSFTNGP11.phx.gbl>...

Any suggestions on how I can make this web service URL dynamic?

YES,
If the Java web service really is exactly the same on all the servers, then
it should use exactly the same WSDL on all those servers. The request and
response namespaces should not vary across different URLs. If you can get
that to happen, then all you need to change is the Url property on the web
service proxy.

Ignoring or over-riding this namespace would be subverting a key mechanism
for synchronizing and versioning services, interfaces, and request and
response messages. So I would advise against it. Instead, fix the
server-side implementation to be more sane..^H^H^H^H. er, ...more
reasonable.

[Drew Marsh]

JL wrote:

Using the VB module that was created for server1, I substitute server2
in the URL property. When calling a function, I get the following
error:

org.xml.sax.SAXException: Deserializing parameter 'wsUser': could not
find deserializer for type
{http://server1.com/cgi-bin/webobject/etc}WSUser.

While I am calling the webservice on server2, it appears that it is
going to server1 for deserializing information and is being rejected.

Any suggestions?

Yikes!!! Looks like they're allowing the namespace of the schema that the
types are declared in to be generated as the webservice's HTTP URL. This
is a serious issue on their side and there's just no way that you can ever
program for this. The namespace for the schema needs to be fixed if you expect
to be able to communicate with a farm of servers distinguished by difference
URLs. As a rough analogy, it would be like me telling you that the .NET (or
Java for that matter) type MyNamesapce.Foo was the same as SomeOtherNamespace.Foo.
Sure the interfaces of the two classes might be 100% indentical, but the
logical identity of the type just isn't the same.

I wish you nothing but the best of luck trying to explain this and even better
luck getting them to fix the problem! :(

Cheers,
Dre