Quartz.net Create with job with Dependency Injection

Question

I am trying to execute a Quartz scheduler job in .NET with a non-empty constructor and I try to use the default Dependency Injection of .NET to supply the dependencies. This is my job class which needs a dependency injection

public class MyJob : IJob 
{
  private readonly ILogger _logger;

  public MyJob(ILogger<MyJob> logger)
  {
    _logger = logger ?? throw new ArgumentNullException(nameof(logger));  
  }

  public Task Execute(IJobExecutionContext context)
  {
    _logger.LogDebug("It's working!");
  }
}

And this is how I build the job

IJobDetail jobDetail = JobBuilder.Create<MyJob>().WithIdentity("MyID", "MyGroup").Build();
var triggerBuilder = TriggerBuilder.Create()
  .WithIdentity("MyID")
  .StartAt(DateTime.Now)
  .WithCronSchedule("*/1 * * * * ?"); // Every second
var trigger = triggerBuilder.Build();
_scheduler.ScheduleJob(jobDetail, trigger)

Now, I have defined in my app configuration the following

// Quartz configuration.
services.AddQuartz(q =>
{
    // Add dependency injection.
    q.UseMicrosoftDependencyInjectionScopedJobFactory(options =>
    {
        // if we don't have the job in DI, allow fallback
        // to configure via default constructor
        options.AllowDefaultConstructor = true;
    });
});
services.AddTransient<MyJob>();
// Also tried services.AddTransient<IJob, MyJob>();

As defined in the documentation on DI . Yet when I rebuild my solution and run the server, the following error is thrown

Quartz.SchedulerException: Problem instantiating class 'MyProject.MyNamespace.Myjob: Cannot instantiate type which has no empty constructor Parameter name: MyJob' ---> System.ArgumentException: Cannot instantiate type which has no empty constructor

Yet, I explicitely defined to add MS DI in the setup for Quartz to use, following their documentation. So how could I nonetheless inject dependencies? I am using Quartz 3.2.4 and I installed the 'Quartz.Extensions.DependencyInjection' package (also 3.2.4).

Answer 1

You should register your jobs and triggers within the AddQuartz . If you look at the official documentation you will see that the ScheduleJob / AddJob / AddTrigger calls are done within the callback which ensures that the DI works. This will probably change in 3.3 version and the job registration won't be that strict anymore.