Delegate to Seam the management of my JBPM4 engine

The problem was really simple, it's just implement a Singleton without writing it :P

I have a simple class, but I just need it to be loaded when the app starts, because my class will load the JBPM4 engine (and that should be done only once - this process may take up to 4 seconds, which will make really slow the first request coming to my End-Point)
But let me write more code and less words
Just add to your class these tags @Name("rtcapProcessExecutor") @Scope(ScopeType.APPLICATION) @Startup @BypassInterceptors @Install(precedence = Install.APPLICATION) public final class RtcapProcessRunner { .... }
Define which method will be your Creation method (Initialization method), on my case the one which will load the Engine @Create public void startup() { try{ log.info("Creating JBPM process engine using configuration file ("+GenericConstants.JBPM_CONFIG_FILE+") and Loading process definition ("+GenericConstants.PROCESS_DEFINITION_FILE+")"); this.processEngine = new Configuration().setResource(GenericConstants.JBPM_CONFIG_FILE).buildProcessEngine(); this.repositoryService = this.processEngine.getRepositoryService(); this.executionService = this.processEngine.getExecutionService(); this.repositoryService.createDeployment().addResourceFromClasspath(GenericConstants.PROCESS_DEFINITION_FILE).setName(GenericConstants.RTCAP).setTimestamp(new Date().getTime()).deploy(); }catch (Exception ex) { log.fatal("Error while loading RTCAP process definition and configuration file",ex); } }
Now the one which will Destroy your class (shutdown my JBPM4 engine) and release resources @Destroy public void shutdown() { log.info("Destroying JBPM process engine"); if (this.processEngine != null) { this.processEngine.close(); } }
and optionally, your Constructor @Constructor public RtcapProcessRunner(){ log.debug("Creating instance of RtcapProcessRunner"); }

Simple, Isnt' it?
Now you can inject this Seam Component using Injection into another Seam Component, just like this
@In(value="rtcapProcessExecutor", create=true, required=true) private RtcapProcessRunner rtcapProcessRunner; ... //And invoke any public method of that instance, just like this this.rtcapProcessRunner.executeProcessInstance(variablesMap, messageEntity); //And always will be the same instance (a Singleton!)