GuiController design

[Maksym Odintsov]

Hi guys. I'm using GuiController class to obtain data class reference and to perform operations needed for GUI like searching records or booking rooms. I can't make my DataRemote class to be DB(data class interface) , because of exceptions that are thrown in the DB interface.
So in the GuiControler class I have one reference to the Data class and other reference to the DataRemote. So in order to avoid many if statements I decided to make Connection class

private class Connection{
        boolean direct=true;
        Connection(ApplicationMode mode){
            if(mode==ApplicationMode.NETWORK_CLIENT)direct=false;
        }
            
        String[] read(int recNo) throws RecordNotFoundException,RemoteException{
            if(direct)
                return directConnection.read(recNo);
            else return remoteConnection.read(recNo);
        }
        void update(int recNo, String[] data, long lockCookie)throws RecordNotFoundException, SecurityException,RemoteException{
            if(direct)
                directConnection.update(recNo, data, lockCookie);
            else remoteConnection.update(recNo, data, lockCookie);    
        }
     
 
        public void delete(int recNo, long lockCookie)throws RecordNotFoundException, SecurityException,RemoteException{
            if(direct)
                directConnection.delete(recNo, lockCookie);
            else remoteConnection.delete(recNo, lockCookie);    
        }
    

        public int[] find(String[] criteria)throws RemoteException{
            if(direct)
                return directConnection.find(criteria);
            else 
                return remoteConnection.find(criteria);    
        }
    

        public int create(String[] data) throws DuplicateKeyException,RemoteException{
            if(direct)
                return directConnection.create(data);
            else return remoteConnection.create(data);    
        }
    

        public long lock(int recNo) throws RecordNotFoundException,RemoteException{
            if(direct)
                return directConnection.lock(recNo);
            else return remoteConnection.lock(recNo);    
        }
    

        public void unlock(int recNo, long cookie)throws RecordNotFoundException, SecurityException,RemoteException{
            if(direct)
                directConnection.unlock(recNo, cookie);
            else remoteConnection.unlock(recNo, cookie);    
        }
    }

How do you think about this approach ? Is it ok for the SCJD or should I rethink my design.

[Alecsandru Cocarla]

You can also use the Adapter pattern to adapt the remote interface to DB, or the other way round.

[Maksym Odintsov]

I'm not shure about Adapter pattern. Can you explain me in details how you would adapt the remote interface to DB ?

[Ulises Pulido]

Well I believe what Alecsandru believed (let me know if I am wrong) is that you may be able to use the Strategy Pattern (Having the interface DB implemented on the directConnection and remoteConnection) and the Adapter Pattern together (Having an instance of directConnection inside remoteConnection and calling the methods from directConnection inside remoteConnection)

    

    interface InterfaceStrategy{
          void doSomething();
    }

    class DirectConnection implements interfaceStrategy{
          public void doSomething(){
                //Stuff
          }
    }

    //Adapter class
    class RemoteConnection implements InterfaceStrategy{
          DirectConnection d = new DirectConnection();
          public void doSomething(){
               d.doSomething();
          }
    }