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cron-utils-scheduler

A Java job scheduler based on cron-utils library. Supports multiple cron formats - even custom ones!

• priority WAITING queue: jobs sorted by date: more recent first. Wait until pulled to EXECUTING queue.
• priority EXECUTING queue: jobs sorted by date: more recent first. A pool of executors retrieves them and executes ASAP.
• watcher thread: every N ms (where N ms <1s), check next job(s) to be executed and assign them to EXECUTING queue
• executor: executes assigned jobs. Notifies execution end state: SUCCEEDED, FAILED
• SUCCEEDED queue: holds last successfuly executed jobs
• FAILED queue: holds last FAILED jobs

Job: provides execution code ExecutionInstance: job+status+date

ExecutionStatus

Consider:

• ability to schedule Runnables
• ability to schedule jobs that must hold no state (except for serializable parameters) and should be created by reflection (support distributed execution in a future)