Are you sure that the services your third-party jar wants to look up via java.util.ServiceLoader.load(Clazz.class) are registered as META-INF/services entries? The problem could be that Lookup.getDefault().lookup(Clazz.class) also looks up services registered in the system file system (layer.xml) in the /Services subdirectory. Also, are you sure that your third-party jar does not specify a particular class loader it finds appropriate when looking up up the service, i.e. using the method signature java.util.ServiceLoader.load(Clazz.class, MyLoader.class)? In the default case, java.util.ServiceLoader.load(Clazz.class) uses Thread.currentThread().getContextClassLoader() to look up the required service, but this may be jdk implementation dependent. Does your external jar require the service at an early phase during start-up? The implementing module may not be fully ready yet. Also, make sure no attempt is made to double load the service interface class from two different classloaders. The NetBeans classloader system allows, in principle, multiple definitions of the same class with the same qualified name. But these are not available on the context classloader. Look through the logs, you get it warning saying something like ".. won't arbitrarily load class x from class loader y and z". Maybe this helps. Boris
On Sat, 17 Aug 2019 at 08:12, Damian Carey <jami...@gmail.com> wrote: > Hi all, > > We have a "mature" (10+ year old) Netbeans Platform Swing product, which > has 35+ modules. This all works well. > > As usual, when one Netbeans module provides an Implementation we find it > from other Netbeans modules using the usual idiom ... > Provider: puts entry in META-INF/services > Consumer: MyClass myObj = Lookup.getDefault().lookup(MyClass.class); > > Our current issue is that we need to add an external jar that is NOT built > using Netbeans, so it can't use Lookup. I have placed this external jar > into a module wrapper, and one of our modules depends on it so we can > successfully start this service as appropriate. Again, everything is > perfect with this setup. > > The problem is that this external jar is looking for services from our > Netbeans platform product, it is seeking them using standard java > ServiceLoader capability, but the implementations are not found. > > I *think* that if we use the Netbeans System ClassLoader then it CAN > locate the implementations, however we don't want to use the system > classloader because it will cause other issues. > > Does anyone have any suggestions on how a wrapped jar might access > Netbeans META-INF/services implementations via vanilla Java ServiceLoader > SPI interface? > > Any suggestions would be hugely appreciated. > > Many thanks, > -Damian > -- Boris Heithecker Dr. Boris Heithecker Lüneburger Str. 30 28870 Ottersberg Festnetz: +49 4205 315834 Mobil: +49 170 6137015
