On 05/29/2018 10:20 PM, Alan Bateman wrote:
On 29/05/2018 21:00, Jochen Theodorou wrote:
Am 24.05.2018 um 19:33 schrieb Robert Scholte:
[...]
I can quote Alan:
Rhino used to be the JS engine in older releases and that may have
been in rt.jar and so loaded by the boot loader. When Nashorn
replaced it (in JDK 8) then it was configured to be defined to the
extension class loader so this is why the code snippet doesn't find it.
how is this handles in JDK 9 now?
In the JDK 8, the Nashorn classes were loaded/defined by the extension
class loader. In JDK 9, the jdk.scripting.nashorn module is mapped to
the platform (formerly extension) class loader. So no real change and
the issue that Robert refers to must be an issue with JDK 8 too. I
can't quite tell if this is the same as what Peter is seeing but if
Maven is creating class loaders with null as the parent then some of
the platform classes, and the classes in the service provider modules,
will not be visible.
-Alan
The reason why this works on JDK 8 and not on JDK 9+ is that in JDK 8,
the platform/system services are declared in the META-INF/services as
resources. While Maven class loader returns null from
ClassLoader.getParent() it still delegates to extension (platform) class
loader when searching for resources (ClassLoader.getResources()) and
loading classes (ClassLoader.loadClass()), so on JDK 8, the service is
found. Not so on JDK 9, which does not present system/platform services
to ServiceLoader which is initialized with a ClassLoader of which the
chain of parent(s) (traversing the ClassLoader.getParent()) does not
lead to platform class loader. On JDK 9, the platform/system services
are not declared as META-INF/services resources, but in the
module-info.class files...
Regards, Peter
