public class Singleton {

    private static Singleton instance;

    // other code, construct, getters, no matter
}

Singleton singleton = Singleton.getInstance();
singleton = null;

private static Class getClass(String classname) throws ClassNotFoundException {
    ClassLoader classLoader = Thread.currentThread().getContextClassLoader();
    if(classLoader == null)
        classLoader = Singleton.class.getClassLoader();
      return (classLoader.loadClass(classname));
}