0x6F00 casting Javacard Shareable Interface

[Romanzi]

I tried to use Shareable Interface Objects for two different packages. There is a package named appClient and one named appServer. ClientApplet.java and ServerAppBankInterface.java are classes in appClient and ServerAppBankInterface.java and ServerApplet.java are in appServer.

In ClientApplet.java, I have problem casting interface in line below. If I delete Try-Catch in that line I receive 0x6F00 error. Why this happened?

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ServerAppBankInterface bankInterface = (ServerAppBankInterface) sio;

Here are the source code below:

ServerApplet.java in appServer

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package appServer;

import javacard.framework.AID;
import javacard.framework.APDU;
import javacard.framework.Applet;
import javacard.framework.ISO7816;
import javacard.framework.ISOException;
import javacard.framework.Shareable;


public class ServerApplet extends Applet implements ServerAppBankInterface{

    public ServerApplet(byte[] bArray, short bOffset, byte bLength){

        register(bArray, (short) (bOffset + 1), bArray[bOffset]);
    }

    public Shareable getShareableInterfaceObject(AID clientID, byte parameter){

        byte[] tempAID = {(byte)0x05, (byte)0x04, (byte)0x03, (byte)0x02, (byte)0x01, (byte)0x01};

        if((clientID.equals(tempAID,
                (short)0,
                (byte)tempAID.length)) == false)
            return  null;
        else
            return this;
    }

    public boolean select()
    {
         return true;
    }

    public static void install(byte[] bArray, short bOffset, byte bLength) {
        new ServerApplet(bArray, bOffset, bLength);
    }

    public void process(APDU apdu) {

        byte[] buf = apdu.getBuffer();
        switch (buf[ISO7816.OFFSET_INS]) {
        case (byte) 0x00:
            break;
        default:
            ISOException.throwIt(ISO7816.SW_INS_NOT_SUPPORTED);
        }
    }

    public short getSavedMoneyInBank() {
        // TODO Auto-generated method stub
        return 0;
    }



}

ServerAppBankInterface.java in appServer

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package appServer;

import javacard.framework.Shareable;

public interface ServerAppBankInterface extends Shareable{
    public short getSavedMoneyInBank();
}

ClientApplet.java in appClient

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package appClient;

import javacard.framework.AID;
import javacard.framework.APDU;
import javacard.framework.Applet;
import javacard.framework.ISO7816;
import javacard.framework.ISOException;
import javacard.framework.JCSystem;
import javacard.framework.Shareable;
import javacard.framework.Util;

public class ClientApplet extends Applet {

    Shareable  sio;

    byte[] serverAID = {(byte)0x01, (byte)0x02, (byte)0x03, (byte)0x04, (byte)0x05, (byte)0x01};

    public ClientApplet() {
    }

    public static void install(byte[] bArray, short bOffset, byte bLength) {
        new ClientApplet().register(bArray, (short) (bOffset + 1),
                bArray[bOffset]);       
    }

    public void process(APDU apdu) {
        if (selectingApplet()) {
            return;
        }
        byte[] buf = apdu.getBuffer();      
        byte cla = buf[ISO7816.OFFSET_CLA];

        if (( cla != ISO7816.CLA_ISO7816) && (cla != (byte) 0x10))
            ISOException.throwIt(ISO7816.SW_CLA_NOT_SUPPORTED);

        switch (buf[ISO7816.OFFSET_INS]) {
        case (byte) 0x00:
             AID svrAid = JCSystem.lookupAID(serverAID, 
                                     (short)0, 
                                     (byte)serverAID.length);

            if(svrAid == null) {
                ISOException.throwIt((short)0x0010);
            }

            sio = JCSystem.getAppletShareableInterfaceObject(svrAid, (byte)0);

            if(sio == null){
                ISOException.throwIt(ISO7816.SW_WRONG_LENGTH);
            }

            try{
                ServerAppBankInterface bankInterface = (ServerAppBankInterface) sio;
            }catch(Exception ex){
                ISOException.throwIt(ISO7816.SW_WRONG_P1P2);
            }


                        break;

        }
    }

}

ServerAppBankInterface.java in appClient

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package appClient;

import javacard.framework.Shareable;

public interface ServerAppBankInterface extends Shareable{
    public short getSavedMoneyInBank();
}

[UNKNwYSHSA]

I was tried it. But no exception found when i cast svrObj to ServerInterface without try ... catch ... statement.
Can you offer more details? Screen shoot of your APDU commands and responses?