JVM Invalid Nested Class Name?

问题

The compiler for a JVM-based programming language currently that I am working on uses this code to run a specified main method after compilation:

URL url = DyvilCompiler.config.outputDir.toURI().toURL();
Class c = Class.forName(mainType, false, new URLClassLoader(new URL[] { url }, ClassLoader.getSystemClassLoader()));
Method m = c.getMethod("main", String[].class);
m.invoke(null, new Object[] { args });

However, when compiling this code:

package dyvil.test
// some uninteresting import stuff
public class Main
{   
    @ArrayConvertible
    case class IntVector([int] ints = [ 1, 2 ])
    
    public static void main([String] args)
    {
        println(IntVector())
        println([ 1, 2, 3 ] as IntVector)
    }
}

The ClassLoader fails with the inner class (that is actually a nested static class):

java.lang.ClassFormatError: Illegal class name "Ldyvil/test/Main$IntVector;" in class file dyvil/test/Main$IntVector
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:760)
    at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
    at java.net.URLClassLoader.defineClass(URLClassLoader.java:455)
    at java.net.URLClassLoader.access$100(URLClassLoader.java:73)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:367)
    at java.net.URLClassLoader$1.run(URLClassLoader.java:361)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(URLClassLoader.java:360)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    at dyvil.test.Main.main(Unknown Source)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:483)
    at dyvil.tools.compiler.util.TestThread.run(TestThread.java:32)

Note that the class files generated for Main dyvil/test/Main and IntVector dyvil/test/Main$IntVector do define the inner class relation:

Inner classes:
    [inner class info: #2 dyvil/test/Main$IntVector, outer class info: #7 dyvil/test/Main
     inner name: #9 IntVector, accessflags: 8 static]
  Enclosing Method: #7  #0 dyvil/test/Main

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What is the problem with the Ldyvil/test/Main$IntVector; signature?

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Also, when adding the output directory to the classpath and changing the code to

Class c = Class.forName(mainType)

everything works well without any errors.

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EDIT: Not only does this cause problems with the JVM, but when using a class like this in Eclipse by importing it, Code Completions stop working completely.

来源：https://stackoverflow.com/questions/30017525/jvm-invalid-nested-class-name