So even if you execute tomcat’s shutdown script, tomcat will only be able to close the sockets, but not the task itself. Why not just replace the loop with a while(true) instead of the task and the very large loop? The sample application runs within tomcat and using the while(true) will never allow the task to shut down. It does this within a loop that executes a million times. The vote method calls the Volt Active Data client repository and adds a vote to a given candidate. The task will make a few method calles and then call the vote() method. In this case, the task is the createVotes() method which will execute 10ms after completion of a previous execution. For the sake of the example, we are focusing on how to set the task up, what the task does and when it executes.įirst, annotate the object as an Second, create a method that will run your task. The code has a lot more than what is shown. The example will use both “fixedDelay” and “fixedRate” and I’ll talk about one important item to consider when designing your scheduled tasks: shutting down your application. The third method is “cron” and follows the standard cron syntax. The second is “fixedDelay” and will execute every N milliseconds upon completion of the previous execution. The first is “fixedRate” and will execute every N milliseconds after the start of the previous execution. Spring will scan my application for the annotation and then initialize the tasks and begin executing them. The above configuration tells Spring that I am using annotations to define scheduled tasks and that I want my scheduler to only have two threads. ![]() Let’s begin by looking at the configuration file. My example executes two tasks, one for writing randomly generated votes for a candidate to a database and another task for reporting on the performance of the database driver. I’ll demonstrate the process with an example from Volt Active Data’s Voter application. It requires two XML configurations and then an annotation for each of your tasks. The Spring framework provides a really simple API for scheduling tasks. It wasn’t terribly hard to implement the logic, but the scheduler was an external component that required much more work to configure than I would have liked. Later, I had to write a similar feature that would run every couple of minutes. It fired up at early in the morning when the server had the lowest utilization.
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