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javaweb-servicessimulationmainframe

How to simulate IMS segment processing via a Java web service


I'm working on a project which involves writing web services on mainframe enviroment.We are going to be provided a test enviroment on which we can do development and see the inital results. That process is taking a lot of time and I wanted to see if I can simulate some of the parts that I've to do.

Finally I've to get web services talking with mainframes which would have webservice talking with DB2 and IMS segments. I've never worked with mainframes before and I wanted to know how can I create mocks for IMS segment which then my webservice can read and update to. I would appreciate any insights into this


Solution

  • I've done the mainframe side of POX and SOAP web services in CICS. (CICS can access both DB2 and IMS) The thing that seems to surprise the distributed folks is the tag names. They tend to be generated from language structures, so they look like (in our case) COBOL variable names.

    Other than that, the SOAP looks like what the WSDL says it should, the POX looks like POX.

    If you've got a schema, work from that. Don't worry about the fact that it's a mainframe or that the data is stored in IMS or DB2, write to the specification.

    You might want to ask about authentication mechanisms, as this is another stumbling block regardless of platform. Generally people are nervous about unauthenticated access to their business systems, even if that access is coming from another part of the same organization. No one wants to have created an exploitable hole in their security.

    In our case, using CICS, we required a logon ID and password for each transaction - http basic authentication as per RFC 2617. Depending on your policies and procedures, that password may be required to expire on a regular basis. Some organizations allow non-expiring IDs, some don't.

    An option we looked at but did not implement was SSL certificates. CICS allows one to send a certificate along with a request and then CICS matches the certificate to a logon ID under whose auspices the rest of the transaction runs. The ID is authenticated by virtue of the certificate. This is done in the TCPIPSERVICE definition in CICS.

    I realize I'm going on about CICS and you didn't even mention it in your question, but I have to believe you're going to run into similar concepts/issues. IMS also does web services, and I seem to remember there being a mechanism to expose a DB2 stored procedure as a web service. IMS, DB2, and CICS all use the same external security manager behind the scenes.