Chapter 1. Introduction

Read this section to gain an overview of the way in which the jBPM works.

The core workflow and business process management functionality is packaged as a simple Java library. This library includes a service that manages and executes JPDL database processes:

This suite contains all of the jBPM components and the following sub-directories:

The JBoss Application Server consists of the following components:

The jPDL also includes the Graphical Process Designer Tool. Use it to design business processes. (It is an Eclipse plug-in and is included with the JBoss Developer Studio product.)

It facilitates a smooth transition from business process modeling to practical implementation, making it of use to both the business analyst and the technical developer.

The Console Web Application serves three purposes. Firstly, it functions as a central user interface, allowing one to interact with those run-time tasks that have been generated by the process executions. Secondly, it is an administrative and monitoring console that allows one to inspect and manipulate run-time instances. The third role of this software is that of business activity monitor. In this role, it presents statistics about the execution of processes. This information is of use to managers seeking to optimize performance as it allows them to find and eliminate bottlenecks.

The Business Process Manager has two core components. These are the "plain Java" (J2SE) library, which manages process definitions, and the run-time environment, which executes process instances.

The jBPM, itself, is a Java library. Consequently, it can be used in any Java environment, be it a web or Swing application, an Enterprise Java Bean or a web service.

One can also package and expose the jBPM library as a stateless session Enterprise Java Bean. Do this if there is a need to create a clustered deployment or provide scalability for extremely high throughput. (The stateless session Enterprise Java Bean adheres to the J2EE 1.3 specifications, mearning that it can be deployed on any application server.)

Be aware that some parts of the jbpm-jpdl.jar file are dependent upon third-party libraries such as Hibernate and Dom4J.

Hibernate provides the jBPM with persistence functionality. Also, apart from providing traditional O/R mapping, Hibernate resolves the differences between the Structured Query Language dialects used by competing databases. This ability makes the jBPM highly portable.

The Business Process Manager's application programming interface can be accessed from any custom Java code in your project, whether it be a web application, an Enterprise Java Bean, a web service component or a message-driven bean.

The jBPM can integrate with any company directory that contains user (and other organizational) data. (For those projects for which no organizational information component is available, use the Identity Component. This component has a "richer" model than those used by traditional servlets, Enterprise Java Beans and portlets.)

The JBoss jBPM Job Executor is a component designed for the purpose of monitoring and executing jobs in a standard Java environment. Jobs are used for timers and asynchronous messages. (In an enterprise environment, the Java Message Service and the Enterprise Java Bean TimerService might be used for this purpose; the Job Executor is best used in a "standard" environment.)

The Job Executor component is packaged in the core jbpm-jpdl library. It can only be deployed in one of the following two scenarios:

Having read this chapter, you have gained a broad overview of the jBPM and its constituent components.