ProviderClass

package java.security;
Provider.class
private Class getImplClass() throws NoSuchAlgorithmException {
	    try {
		Reference<Class> ref = classRef;
		Class clazz = (ref == null) ? null : ref.get();
		if (clazz == null) {
		    ClassLoader cl = provider.getClass().getClassLoader();
		    if (cl == null) {
			clazz = Class.forName(className);
		    } else {
			clazz = cl.loadClass(className);
		    }
		    classRef = new WeakReference<Class>(clazz);
		}
		return clazz;
	    } catch (ClassNotFoundException e) {
		throw new NoSuchAlgorithmException
	            ("class configured for " + type + "(provider: " + 
		    provider.getName() + ")" + "cannot be found.", e);
	    }
	}

=>Avoiding problems of default system class loader

private Class getKeyClass(String name) {
	    try {
		return Class.forName(name);
	    } catch (ClassNotFoundException e) {
		// ignore
	    }
	    try {
		ClassLoader cl = provider.getClass().getClassLoader();
		if (cl != null) {
		    return cl.loadClass(name);
		}
	    } catch (ClassNotFoundException e) {
		// ignore
	    }
	    return null;
	}

=>Avoiding problems of default system class loader