I have a COM+ component developed with VB6.
After registering it with the component services manager COM+ application, I can use it from ASP like this
Set Comando = Server.CreateObject("JuiciosComando.clsComando")
ComandoExecute = Comando.execute(Xml)
Set Comando = Nothing
That's all I need, the component just receives a (maybe a huge) string and returns another (also possibly huge) string...
Is there some way to access this very same component from Java?
What I've found so far is J-Integra but it's a commercial product.
I've also found this thread on codeguru.com but my C++.NET knowledge is rather poor, besides I would rather just find a free, pure Java solution.
As Eddie mentioned, you have two main methods of using COM via java: using C++ and writing a JNI wrapper or using a third party JAR to wrap the COM object.
I've attempted to use C++ to wrap a COM object in the past - it's not for the faint hearted - it is not easy to do and its very easy to leak resources.
I've also used two third party JAR's: ComfyJ and JACOB.
ComfyJ was really easy to use and also included a codegen utility to generate java wrapper classes for your COM classes.
It can be downloaded and trialed via http://www.teamdev.com/comfyj/index.jsf
(I am not affiliated with TeamDev in any way!)
If you are desperate for a totally free solution, you could also try JACOB (http://sourceforge.net/projects/jacob-project/).
I had issues with documentation, but it was relatively stable.