I am writing a JCA resource adapter. I'm also, as I go, trying to fully understand the connection management portion of the JCA specification. As a thought experiment, pretend that the only client of this adapter will be a Swing Java Application Client located on a different machine. Also assume that the resource adapter will communicate with its "enterprise information system" (EIS) over the network as well.
As I understand the JCA specification, the .rar file is deployed to the application server. The application server creates the .rar file's implementation of the ManagedConnectionFactory interface. It then asks it to produce a connection factory, which is the opaque object that is deployed to JNDI for the user to use to obtain a connection to the resource. (In the case of JDBC, the connection factory is a javax.sql.DataSource.)
It is a requirement that the connection factory retain a reference to the application-server-supplied ConnectionManager, which, in turn, is required to be Serializable. This makes sense--in order for the connection factory to be stored in JNDI, it must be serializable, and in order for it to keep a reference to the ConnectionManager, the ConnectionManager must also be serializable. So fine, this little object graph gets installed in the application client's JNDI tree.
This is where I start to get queasy. Is the ConnectionManager--the piece supplied by the application server that is supposed to handle connection management, sharing, pooling, etc.--wholly present on the client at this point? One of its jobs is to create ManagedConnection instances, and a ManagedConnection is not required to be Serializable, and the user connection handles it vends are also not required to be Serializable. That suggests to me that the whole connection pooling machinery is shipped wholesale to the application client and stuffed into its JNDI tree.
Does this all mean that JCA interactions from the client side bypass the server-side componentry of the application server? Where are the network boundaries in the JCA API?
