how to create a generic singleton class in java?

i want to create a generic singleton class in java witch gives singleton object of class which i pass in method parameter. some thing like below code : please help

public final class Listener<T extends Object>  {
    private Listener() {
    }

    public static <T> Listener<?> getInstance(Class<T> clazz) {
        return SingletonHolder.INSTANCE;
    }

    private static class SingletonHolder {
        public static final Listener INSTANCE = new Listener();
        // private static final Map<Class<? extends Runnable>,Listener<? extends
        // Runnable> INSTANCE = new ...;
    }
}