BSF4ooRexx 850 Beta: Exploiting ooRexx 5.0 Direct and Redirecting Command Environment Handlers Implemented in Java/NetRexx

Since 2012 BSF4ooRexx supports defining Rexx exits and Rexx command handlers (cf. rexxapi.pdf, "1.15 Rexx Exits Interface" and "1.16 Command Handler Interface") and supplies quite a few examples of Java handler implementations stored in the "samples/Java/handlers" subdirectories of the BSF4ooRexx installation. This infrastructure can be used in ooRexx 4.1 and later to configure a Rexx instance (ooRexx allows for many different Rexx instances, that each may be configured differently in parallel) with them such that Rexx programs can take advantage of each registered command handler (implemented in Java or NetRexx).
ooRexx 5.0 introduces the ability to define Rexx direct ("classic") and redirectable command handlers and in addition allows for registering by a Rexx program at runtime and then take advantage of the added commands. BSF4ooRexx 850 implements this support, redesigned the handler related abstract and interface classes to unify them in a subtree and exploits the Java 8 feature of default interface methods. This presentation introduces the updated Rexx command handler infrastructure in BSF4ooRexx 850, the architecture and some deployment scenarios. Direct and redirecting command handlers implemented in Java and exploited in ooRexx serve as samples that allow one to assess the easiness and power this infrastructure makes available to Rexx programmers.