OSWorkflow is a Java-based open-source workflow engine. It helps you to focus your work on the business logic and rules rather than working on heavy coding. Integrating OSWorkflow into your application is very easy and fast. OSWorkflow provides all of the workflow constructs that you might come across in real-life processes like steps, conditions, loops, splits, joins, roles, etc. The latest version of OSWorkflow has a GUI for developing workflows, which simplifies creating workflows for simple needs. To get the best out of it, creating workflows by XML coding is recommended. OSWorkflow takes advantage of many existing Java open-source projects, including:
BeanShell: For workflow scripting
OpenForBusiness: Entity engine persistence support
GLUE: For a SOAP interface
Quartz: For job scheduling
OSWorkflow can work in any J2EE container, including servlet containers (EJB support does not work here). OSWorkflow was designed to be as flexible as possible to fit the needs of many unique requirements.
This book explains OSWorkflow, without assuming any prior knowledge of Business Process Management. Real-life examples are used to clarify concepts. It gives step-by-step instructions on how to do things. The basics are explained first and then examples help to clarify and reinforce the principles.
Chapter 1 gives an overview of the BPM technology and the workflow engine, along with an analysis of the different types of BPMS.
Chapter 2 introduces OSWorkflow and teaches the basics of the workflow engine along with a real-life example.
Chapter 3 introduces several key features of OSWorkflow like handling persistent and transient variables, variable interpolation, built-in OSWorkflow functions, Conditions, and BeanShell scripting.
Chapter 4 covers Persistence of variables across invocations, and the FunctionProviders along with integrating OSWorkflow with Spring.
Chapter 5 introduces and integrates Rules engine and Drools open-source rule engine.
In Chapter 6 we explore the Quartz task scheduler and its integration with OSWorkflow and we give a tutorial with Quartz sending events and actions to OSWorkflow.
Chapter 7 introduces Event Stream Processing and Complex Event Processing. We give an OSWorkflow function provider that interfaces with the ESPer CEP engine and allows the monitoring of real-time process information and events.
Chapter 8 gives OSWorkflow visualization of its business process information with the Pentaho open-source BI solution. Using the charting capabilities of Pentaho we build an enterprise process dashboard to monitor and analyze the processes.
The book is aimed at experienced Java developers and system architects who want to develop complex Java applications using the OSWorkflow workflow engine. OSWorkflow is a flexible low-level workflow implementation for developers and architects; it is not a quick "plug-and-play" solution for non-technical end users.
In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.
There are three styles for code. Code words in text are shown as follows: "The OSWorkflow descriptor XML must have a root element of workflow and obligatory child elements named steps and initial-actions."
A block of code will be set as follows:
… <steps> <step id="1" name="Employee request"> <actions> <action id="1" name="Request holidays"> <results> <unconditional-result old-status="Finished" step="2" status="Requested"/> </results> </action> </actions> </step> …
When we wish to draw your attention to a particular part of a code block, the relevant lines or items will be made bold:
<actions>
<action id="1" name="Action 1">
<results>
<unconditional-result old-status="Finished" status= "Pending" split="1"/>
</results>
</action>
</actions>
New terms and important words are introduced in a bold-type font. Words that you see on the screen, in menus or dialog boxes for example, appear in our text like this: "You can simply click on the Authors link located on the books listing page in your browser."
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