Integrate Quartz.NET with your favourite IoC container

I've used a job scheduler library called Quartz.NET in a couple of projects. This blogpost describes how to integrate it with your favourite flavoured IoC-container.

This applies to Quartz.NET version 1.0.3 that is also available on NuGet by package name "Quartz".

Jobs are implemented by implementing one of the job-interfaces IJob, IInterruptableJob or IStatefulJob (they are all based on IJob). The job is then registered with a scheduler and a trigger.

The initialization code below is also described in Lesson 1 of Quartz.NET tutorial:

// construct a scheduler factory
ISchedulerFactory schedFact = new StdSchedulerFactory();

// get a scheduler
IScheduler sched = schedFact.GetScheduler();
sched.Start();

// construct job info
JobDetail jobDetail = new JobDetail("myJob", null, typeof(HelloJob));
// fire every hour
Trigger trigger = TriggerUtils.MakeSecondlyTrigger(5);
trigger.Name = "myTrigger";
sched.ScheduleJob(jobDetail, trigger);

This is fine as long as the job doesn't require a dependency. But what if your Job implementation demands a dependency?

public class HelloJob : IJob
{
    private readonly ILogger _logger;

    public HelloJob(ILogger logger)
    {
        _logger = logger;
    }

    public void Execute(JobExecutionContext context)
    {
        _logger.Log(@"Oh Hai \o/");
    }
}

Then you need to roll your own IJobFactory implementation. My implementation with my favourite IoC container Castle Windsor is described below:

public class WindsorJobFactory : IJobFactory
{
    private readonly IWindsorContainer _container;

    public WindsorJobFactory(IWindsorContainer container)
    {
        _container = container;
    }

    public IJob NewJob(TriggerFiredBundle bundle)
    {
        return (IJob)_container.Resolve(bundle.JobDetail.JobType);
    }
}

The JobFactory instance then needs to be assigned to the scheduler in the initialization code:

var container = new WindsorContainer();
IJobFactory jobFactory = new WindsorJobFactory(container);

ISchedulerFactory schedFact = new StdSchedulerFactory();

IScheduler sched = schedFact.GetScheduler();
sched.JobFactory = jobFactory;
sched.Start();

I'm aware that you should not call your IoC-container directly, instead adhere to The Hollywood principle, but I think its ok in this case because it's the initialization of the infrastructure. The job implementations must also be registered with your IoC-container:

public class JobRegistrar
{
    private readonly IWindsorContainer _container;

    public JobRegistrar(IWindsorContainer container)
    {
        _container = container;
    }

    private static IEnumerable GetJobTypes()
    {
        return AppDomain.CurrentDomain.GetAssemblies().ToList()
            .SelectMany(s => s.GetTypes())
            .Where(p => typeof(IJob).IsAssignableFrom(p) && !p.IsInterface);
    }

    public void RegisterJobs()
    {
        var jobTypes = GetJobTypes();
        foreach (Type jobType in jobTypes)
        {
           _container.Register(Component.For(jobType).ImplementedBy(jobType).LifeStyle.Transient);
        }
    }
}

That's all for tonight folks! All code can be found on my GitHub account