Process Commander provides three Java-based service
interfaces (EJB, Java, and JSR94) that you can use to request
services using a signature-based or an engine API
invocation-based invocation style:
- Signature-based means the external application
invokes the Process Commander service rules through the proxy
EJB or Java archive generated by the service package. The
proxy publishes the method signatures of the service rules. A
client application sends the input to the service rule by
calling a method in the proxy — a method with
parameters that match the service rule. The proxy manages
type validation, constructs the URI for the service rule, and
so on.
- Engine API invocation means the external
application invokes the Process Commander service rules
through a (generic) business delegate, directly through the
PRService EJBs, or through an instance of the
PegaRULES engine. The client application calls one Java
method no matter which service rule is targeted in Process
Commander. The parameters provided in the invocation identify
the service rule and provide the input for the service rule.
Unlike the signature-based style, no compile-time validation
of method names and parameters does not occur, because you
are not using a proxy compiled by Process Commander.
Service EJB rules and Service Java rules support both
invocation styles. Service JSR94 rules support the engine API
invocation style only, in accord with the JSR 94
specification.
Which service rule type and invocation style is best depends
on your situation and needs. For example:
- If the external calling application is an enterprise
application, use Service EJB rules with a generated
proxy.
- If your organization seeks to comply with the JSR 94
specification, use Service JSR94.
- For a POJO (plain old Java object) interface to Process
Commander, use Service Java rules, with or without a
generated proxy.
For more information, see Building EJB
Services and Building JSR-94 Services, two documents
available on the Integration area of the Pega Developer
Network.
Integration-Services category