Both people-oriented and system-oriented BPM systems need a mechanism to execute tasks within an event or temporal constraint, for example, every time a state change occurs or every two weeks. BPM suites address these requirements with a job-scheduling component responsible for executing tasks at a given time.
OSWorkflow, the core of our open-source BPM solution, doesn't include these temporal capabilities by default. Thus, we can enhance OSWorkflow by adding the features present in the Quartz open-source project.

What is Quartz?

Quartz is a Java job-scheduling system capable of scheduling and executing jobs in a very flexible manner. The latest stable Quartz version is 1.6. You can download Quartz from http://www.opensymphony.com/quartz/download.action.

Installing

The only file you need in order to use Quartz out of the box is quartz.jar. It contains everything you need for basic usage. Quartz configuration is in the quartz.properties file, which you must put in your application's classpath.

Basic Concepts

The Quartz API is very simple and easy to use. The first concept that you need to be familiar with is the scheduler. The scheduler is the most important part of Quartz, managing as the word implies the scheduling and unscheduling of jobs and the firing of triggers.
A job is a Java class containing the task to be executed and the trigger is the temporal specification of when to execute the job. A job is associated with one or more triggers and when a trigger fires, it executes all its related jobs. That's all you need to know to execute our Hello World job.

Integration with OSWorkflow

By complementing the features of OSWorkflow with the temporal capabilities of Quartz, our open-source BPM solution greatly enhances its usefulness. The
Quartz-OSWorkflow integration can be done in two ways—Quartz calling OSWorkflow workflow instances and OSWorkflow scheduling and unscheduling Quartz jobs. We will cover the former first, by using trigger-functions, and the latter with the ScheduleJob function provider.

Creating a Custom Job

Job's are built by implementing the org.quartz.Job interface as follows:

The interface is very simple and concise, with just one method to be implemented. The Scheduler will invoke the execute method when the trigger associated with the job fires. The JobExecutionContext object passed as an argument has all the context and environment data for the job, such as the JobDataMap.
The JobDataMap is very similar to a Java map but provides strongly typed put and get methods. This JobDataMap is set in the JobDetail file before scheduling the job and can be retrieved later during the execution of the job via the JobExecutionContext's getJobDetail().getJobDataMap() method.

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