问题
I have two jobs, consider them to be the super simple jobs that just print a line and have no triggers or timeouts defines. They work fine when I call them from a controller class through: <name of my class>Job.triggerNow()
What I want is to trigger one job and, as it as it finishes, trigger a consequent different job.
I have tried using the quartzScheduler, but I can't seem to get a JobDetail from my job classes, so I'm not sure what is the correct way for doing this. I also want to pass some results from the first job onto the second one.
I know I can trigger the second job as the last line on my first job's execute method, but this is not desirable since its technically not part of the first job and couples things more than I would like.
Any help will be greatly appreciated. thanks
回答1:
What it sounds like you are after is an asynchronous "pipeline" of work where there are different workers that are all in a line and pass data to be worked on from one to the next. This sort of architecture is amazingly flexible and applies to a large number of very common applications
The best way that I have found to get such an architecture in place with Grails is to use a message queue, like RabbitMQ for example, with a series of queues (one for each step in the pipeline), and then have the controller(s) put messages into the first step of the pipeline.
Then, you have a worker (just a service within the Grails app if you use the excellent RabbitMQ Grails plugin) listen to the queue that holds jobs for them to work on. As work comes into the queue, the worker will pop the job off, processes it, and then put a message into the queue of the next step in the pipeline.
I've found this to be the best way to architect just about any asynchronous pipeline, since it allows you to scale each piece separately as needed and doesn't have too much overhead. There are also ways to decouple the jobs from having to know about the next step in the pipeline, but I've found that in most cases this isn't really needed and just adds useless complexity.
Quartz is great for jobs that need to happen on a schedule, but a pipeline is much better at processing things as it comes in in a scaleable way
回答2:
Please have a look @ JobListener
You can utilize
public void jobWasExecuted(JobExecutionContext context,
JobExecutionException jobException);
回答3:
I built something similar to this in my web application using queue messaging technique with Redis. I simply define the dependency structure for all the jobs, and have a master job with the only purpose is to monitor/update the status of other jobs and trigger dependent jobs if needed.
Each job will have to report its status running/finish/cancel using the Redis queue. Master job pop each queue message and process it properly.
来源：https://stackoverflow.com/questions/9776543/how-do-i-trigger-a-job-when-another-completes