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Some enterprise information systems provide advanced support for transaction and security. For example, some systems support controlled access to their resources through transactions. These systems can participate in transactions with others by supporting two-phase commit protocol, managed by a transaction manager supported by a J2EE server. Other systems offer limited or almost no support for transactional access. For example, a system may only support transactions that are coordinated internally.
Legacy systems or applications that have been in existence for a long time may impose specific technology and administrative restrictions. For example, it may be difficult to create new user accounts in a legacy system or to extend this system to support development of new applications. In this case, an Application Component Provider has to live with what exists and enable access to such systems under restrictions. This may be a very typical situation.
When developing an application to integrate enterprise information systems, an Application Component Provider has to be aware of its functional and system capabilities, and design application components taking into account possibilities and limitations of the system. For example, application components should not be developed and deployed so that they require transactions spanning multiple resource managers if the J2EE server cannot really provide support for such transactions due to the fact that the participating enterprise information system resource managers do not support the two-phase commit protocol. In other cases, application components may need to limit their security requirements due to constraints of the underlying system.