Implemented issue: #65

jse/src/main/java/org/luaj/vm2/libs/jse/LuajavaLib.java

@@ -242,7 +242,26 @@ public class LuajavaLib extends VarArgFunction {
 
 	// load classes using app loader to allow luaj to be used as an extension
 	protected Class classForName(String name) throws ClassNotFoundException {
-		Class clazz = Class.forName(name, true, ClassLoader.getSystemClassLoader());
+		Class clazz = null;
+		ClassLoader contextLoader = Thread.currentThread().getContextClassLoader();
+		if (contextLoader != null) {
+			try {
+				clazz = Class.forName(name, true, contextLoader);
+			} catch (ClassNotFoundException ignored) {
+			}
+		}
+		if (clazz == null) {
+			ClassLoader libraryLoader = getClass().getClassLoader();
+			if (libraryLoader != null) {
+				try {
+					clazz = Class.forName(name, true, libraryLoader);
+				} catch (ClassNotFoundException ignored) {
+				}
+			}
+		}
+		if (clazz == null) {
+			clazz = Class.forName(name, true, ClassLoader.getSystemClassLoader());
+		}
 		if (!isClassVisible(clazz))
 			throw new ClassNotFoundException("class is not visible: " + name);
 		return clazz;

jse/src/test/java/org/luaj/vm2/libs/jse/LuajavaLibClassLoaderTest.java

@@ -0,0 +1,36 @@
+package org.luaj.vm2.libs.jse;
+
+import junit.framework.TestCase;
+
+public class LuajavaLibClassLoaderTest extends TestCase {
+
+	public void testClassForNameFallsBackToLibraryLoader() throws Exception {
+		ExposedLuajavaLib lib = new ExposedLuajavaLib();
+		ClassLoader previous = Thread.currentThread().getContextClassLoader();
+		Thread.currentThread().setContextClassLoader(new RejectingClassLoader());
+		try {
+			Class clazz = lib.exposedClassForName(LocalVisibleClass.class.getName());
+			assertEquals(LocalVisibleClass.class, clazz);
+		} finally {
+			Thread.currentThread().setContextClassLoader(previous);
+		}
+	}
+
+	static final class ExposedLuajavaLib extends LuajavaLib {
+		Class exposedClassForName(String name) throws ClassNotFoundException {
+			return classForName(name);
+		}
+	}
+
+	static final class RejectingClassLoader extends ClassLoader {
+		protected Class<?> loadClass(String name, boolean resolve) throws ClassNotFoundException {
+			if (LocalVisibleClass.class.getName().equals(name)) {
+				throw new ClassNotFoundException(name);
+			}
+			return super.loadClass(name, resolve);
+		}
+	}
+
+	public static final class LocalVisibleClass {
+	}
+}