Use custom class loader for autoclass

[hanslovsky]

We are currently trying to use groovy grape to load classes from jars that were not on the initial class path to allow for a more interactive scripting experience. We can resolve and download the required jars but we cannot load the classes through autoclass. It seems the issue is with FindClass:

Since Java 2 SDK release 1.2, when FindClass is called through the Invocation Interface, there is no current native method or its associated class loader. In that case, the result of ClassLoader.getSystemClassLoader is used. This is the class loader the virtual machine creates for applications, and is able to locate classes listed in the java.class.path property.

We tried replicating autoclass to accept a class object that was created like this:

loaded_class = java.lang.ClassLoader.loadClass(clazz)
autoclass(loaded_class)
print(loaded_class)

<Class at 0x7f9ab7a70468 jclass=java/lang/Class jself=<LocalRef obj=0x106e178 at 0x7f9ab7a863f0>>

I do not know how to replicate
reflect.py:159:
More specifically, I cannot replicate jnius_export_func.pxi:30-33

cls = Class(noinstance=True)
cls.instanciate_from(create_local_ref(j_env, jc))
j_env[0].DeleteLocalRef(j_env, jc)
return cls

for loaded_class as created through a custom class loader as above.

If you have some hints or pointers for me, what I need to modify, I am willing to make the changes and create the PR.

Related to this, is there a way to access the jenv or is the method get_jnienv exposed?

[hanslovsky]

If you have any hints on this, we would gladly do our part and add custom class loader functionality in a pull request. At the moment, we are kind of at a dead end here, though.

[bnuzhouwei]

Is there any progress in the past few years, the feature is alow import for many cases to extension a powfully pluigein system.

[cmacdonald]

cant you use you access your own classloader from Python, and then use its loadClass(str) method?