JAX-RPC handlers interact with messages as they pass into and out from the service integration bus. Handlers monitor messages at ports, and take appropriate action depending upon the sender and content of each message.
A Java API for XML-based remote procedure call (JAX-RPC) handler is a Java class that performs handling tasks. For example logging messages, or transforming their contents, or terminating an incoming request.
JAX-RPC is part of the Java 2 Platform, Enterprise Edition (J2EE) 1.4, and JAX-RPC handlers are emerging as the standard approach in Java for intercepting and filtering service messages. JAX-RPC handlers are being widely implemented, and any JAX-RPC handlers you write for use in other systems can also be configured for use with a service integration bus. JAX-RPC handlers are already accepted as the standard approach in Java for managing message-level security as defined by the Web Services Security (WS-Security) specification.
For more detailed information about JAX-RPC and JAX-RPC handlers, see the IBM developerWorks article Support for J2EE Web Services in WebSphere Studio Application Developer V5.1 -- Part 3: JAX-RPC Handlers.
You configure a JAX-RPC handler as described in Creating a new JAX-RPC handler configuration. To enable JAX-RPC handlers to perform more complex operations, you chain them together into handler lists. You can then associate each JAX-RPC handler list with one or more ports, so that the handler list can monitor activity at the port, and take appropriate action depending upon the sender and content of each message that passes through the port.
If you create a proxy service configuration, then you must also create a JAX-RPC handler that can set the target endpoint for the proxy service, and attach it to the inbound port. For more information, see JAX-RPC handlers and proxy operation.