Thread: ClassLoader and inner classes

I have this method (in my own classloader) that loads classes from zip:

ZipInputStream in = new ZipInputStream(new FileInputStream(zip));
ZipEntry entry;
while ((entry = in.getNextEntry()) != null) {
	if (!entry.isDirectory()) {
		byte[] buffer = new byte[(int) entry.getSize()];
		in.read(buffer);
		if (!entry.getName().endsWith(".class"))
			continue;
		String name = entry.getName().replace(".class", "").replace("/", ".");
		Class<?> cls = this.defineClass(name, buffer, 0, buffer.length);
		this.resolveClass(cls);
	}
}

The zip that im trying to load looks like this:

TestClass.class
TestClass$SomeOtherInnerClass.class

My problem is that defineClass() fails to load the TestClass$SomeOtherInnerClass. If this class is loaded before the actual TestClass i get this:

java.lang.NoClassDefFoundError: TestClass

I also tried to load the TestClass.class first but then im getting this error:

java.lang.ClassFormatError: Wrong InnerClasses attribute length in class file TestClass

Please help me

The problem is that the class loader cannot load the inner class. For example, URLClassLoader assumes all requests are for outer classes.

Try this:
Thread.currentThread().getContextClassLoader().loa dClass( classFQN );

This works, even for inner classes. Many people recommend creating your own class loader or extending URLClassLoader but that is not actually necessary, most of the time.