Quartz can run embedded within another free standing application
Quartz can be instantiated within an application server (or servlet container), and participate in XA transactions
Quartz can run as a stand-alone program (within its own Java Virtual Machine), to be used via RMI
Quartz can be instantiated as a Cluster of stand-alone programs (with load-Balance and fail-over capabilities)
Jobs are scheduled to run when a given Trigger occurs. Triggers can be created with nearly any Combination of the following directives:
at a certain time of day (to the millisecond)
on certain days of the week
on certain days of the month
on certain days of the year
not on certain days listed within a registered Calendar (such as business holidays)
repeated a specific number of times
repeated until a specific time/date
repeated indefinitely
repeated with a delay interval
Jobs can be any Java class that implements the simple Job interface, leaving infinite possibilities for the work your Jobs can perform.
Job class instances can be instantiated by Quartz, or by your application's framework.
When a Trigger occurs, the scheduler notifies zero or more Java objects implementing the JobListener and TriggerListener Interfaces (listeners can be simple Java objects, or EJBs, or JMS publishers, etc.). These listeners are also notified after the Job has executed.
As Jobs are completed, they return a JobCompletionCode which informs the scheduler of success or failure. The JobCompletionCode can also instruct the scheduler of any actions it should take based on the success/fail code - such as immediate re-Execution of the Job.
The design of Quartz includes a JobStore interface that can be implemented to provide various mechanisms for the storage of jobs.
With the use of the included JDBCJobStore, all Jobs and Triggers configured as "non-volatile" are stored in a relational database via JDBC.
