Java -- MainFrame communication

[Manohar Karamballi]

Hi,
I have a requirement that Java application needs to talk with legacy system running in Mainframe. Pls sugggest me various ways I can do this with their pros and cons...

Your suggestions are appreciated.
TIA,
Manohar

[Barry Gaunt]

How is the mainframe going to let you in?
What's at the mainframe end?
You could take a look at IBM Message Queue over SNA or TCP/IP.
Corba?
Ftp?
Pros/Cons? - that's work
-Barry

[Paul Done]

There are various J2EE oriented integration products out there which can integrate with legacy mainframe systems/programs and expose these functions as Web Services, JCA, etc.. (for example: the Composer product from Novell).
Here's a few ways these products integrate with mainframes:

3270 Screen Scraping - the integration tool simulates a real user by interacting with the system at the screen level and 'scrapes' the results. Not as ideal as going into the system at the business transaction level but often is the only way.

CICS-RPC - If the logic is in a CICS managed transaction processing environment. This uses CICS's External Call Interface, often through IBM's CICS Java gateway. This is more ideal than screen scrapping because integration occurs at the business logic level.

As mentioned before you may be able to use JMS to integrate with MQSeries which in turn may integrate with the mainframe programs. Again, this is a good option because it operates at the business logic level and also it may provide some extra fault tolerance and resilience if the mainframe goes down for a period, for instance.

Hope this helps
Paul