public class DynamicSPIRegistry extends java.lang.Object
{
    private static DynamicSPIRegistry sharedInstance;
    private java.util.Map<java.lang.Class, java.util.Set<DynamicSPIListener> > listenerRegistry;
    private java.util.List<java.lang.ClassLoader> classLoaderMemory;

    private DynamicSPIRegistry()
    {
        super();
        listenerRegistry=new java.util.HashMap<>();
        classLoaderMemory=new java.util.LinkedList<>();
    }
    public static DynamicSPIRegistry getSharedInstance()
    {
        if(sharedInstance==null)
            sharedInstance=new DynamicSPIRegistry();
        return sharedInstance;
    }
    public synchronized <T> void addListener( java.lang.Class<T> iface,DynamicSPIListener<T> listener)
    {
        if((iface!=null)&&(listener!=null))
        {
            if(listenerRegistry.containsKey(iface)==false)
                listenerRegistry.put(iface,new java.util.HashSet<>());
            listenerRegistry.get(iface).add(listener);
            update(iface);
        }
    }
    public synchronized <T> void removeListener(java.lang.Class<T> iface,DynamicSPIListener<T> listener)
    {
        if((iface!=null)&&(listener!=null))
        {
            if(listenerRegistry.containsKey(iface))
            {
                listenerRegistry.get(iface).remove(listener);
            }
        }
    }
    private void update()
    {
        for(java.lang.Class iface:listenerRegistry.keySet())
            update(iface);
    }
    private void update(java.lang.Class iface)
    {
        java.lang.ClassLoader latch=java.lang.Thread.currentThread().getContextClassLoader();
        if(listenerRegistry.containsKey(iface))
        {
            java.util.Set<DynamicSPIListener> listeners=listenerRegistry.get(iface);
            java.util.List<java.lang.ClassLoader> cll=new java.util.LinkedList(classLoaderMemory);
            java.util.Collections.reverse(cll);
            for(java.lang.ClassLoader cl:cll)
            {
                java.lang.Thread.currentThread().setContextClassLoader(cl);
                java.util.ServiceLoader loader = java.util.ServiceLoader.load(iface);
                java.util.Iterator it = loader.iterator();
                java.lang.Object ref=null;
                while (it.hasNext()) {
                    ref = it.next();
                    break;
                }
                if(ref!=null)
                {
                    for(DynamicSPIListener listener:listeners)
                    {
                        listener.implementationAvailable(iface.cast(ref));
                    }
                }
            }
        }
        java.lang.Thread.currentThread().setContextClassLoader(latch);
    }
    public synchronized void setContextClassLoader(java.lang.ClassLoader cl)
    {
        java.lang.Thread.currentThread().setContextClassLoader(cl);
        classLoaderMemory.add(cl);
        update();
    }
    public interface DynamicSPIListener<T>
    {
        void implementationAvailable(T Implementation);
    }
}