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