I would like to create a singleton instance of a class that is not involved in Jersey as a Resource or Service and yet would like its dependencies injected from the Jersey ServiceLocator.
I can register this class manually in my ResourceConfig constructor, the ResourceConfig is then passed in to the Grizzly factory method like so:
ResourceConfig resourceConfig = new DeviceServiceApplication();
LOGGER.info("Starting grizzly2...");
return GrizzlyHttpServerFactory.createHttpServer(BASE_URI,
resourceConfig, mServiceLocator);
The problem that remains is how to get a reference to the Jersey ServiceLocator so I can call createAndInitialize() to get my object with dependencies injected. I see in previous Jersey versions there were constructor variants that expect an ApplicationHandler, which of course provides access to the service locator (how I initialise that is another matter). You can also see I have tried passing in a parent ServiceLocator but of course the resolution happens from child -> parent locator and not in the other direction so asking the parent for my object fails because the Jersey @Contract and @Service types aren't visible here.
Do I need to use something other than GrizzlyHttpServerFactory ? Do I give up and manually wire my singleton's dependencies?
I was able to get a reference to ServiceLocator
by registering a ContainerLifecycleListener
.
In the onStartup(Container container)
method, call container.getApplicationHandler().getServiceLocator()
.
This example stores the reference as a member variable of ResourceConfig
which you can use elsewhere via an accessor.
class MyResourceConfig extends ResourceConfig
{
// won't be initialized until onStartup()
ServiceLocator serviceLocator;
public MyResourceConfig()
{
register(new ContainerLifecycleListener()
{
public void onStartup(Container container)
{
// access the ServiceLocator here
serviceLocator = container.getApplicationHandler().getServiceLocator();
// ... do what you need with ServiceLocator ...
MyService service = serviceLocator.createAndInitialize(MyService.class);
}
public void onReload(Container container) {/*...*/}
public void onShutdown(Container container) {/*...*/}
});
}
public ServiceLocator getServiceLocator()
{
return serviceLocator;
}
}
then elsewhere:
MyService service
= myResourceConfig.getServiceLocator().createAndInitialize(MyService.class);