我试图使用可共享接口,使用Eclipse 3.7 SDK在Java卡2.2.2中创建一个简单的客户端和服务器小程序.调用方法JCSystem.getAppletShareableInterfaceObject时,它将引发异常,因此返回SW设置为6F00.

这是客户端应用程序代码(Test_Client.java)：

    package client;

import server.Test_ServerInf;
import javacard.framework.AID;
import javacard.framework.APDU;
import javacard.framework.Applet;
import javacard.framework.ISO7816;
import javacard.framework.ISOException;
import javacard.framework.JCSystem;

public class Test_Client extends Applet {

    protected static final byte INS1 = (byte)0xE2;
    protected static final byte INS2 = (byte)0x21;

    byte[] ServerAIDbyte={(byte)0x20,(byte)0x21,(byte)0x22,(byte)0x23,(byte)0x24,(byte)0x25,(byte)0x26,(byte)0x27,(byte)0x01};
    AID ServerAID;

    private Test_Client() {
    }

    public static void install(byte bArray[], short bOffset, byte bLength)
            throws ISOException {
        new Test_Client().register();
    }

    public void process(APDU apdu) throws ISOException {
        // TODO Auto-generated method stub
        byte[] apduBuffer = apdu.getBuffer();

        byte Ins=apduBuffer[ISO7816.OFFSET_INS];
        short byteread = apdu.setIncomingAndReceive();

        if (selectingApplet())
            return;

        switch (Ins){
        case INS1:
            Ins1_Handler(apdu);
            return;
        case INS2:
            Ins2_Handler(apdu,apduBuffer);
            return;
        default:
            ISOException.throwIt(ISO7816.SW_FUNC_NOT_SUPPORTED);
        }
    }
    private void Ins1_Handler(APDU apdu){
        Test_ServerInf sio = null;
        ServerAID=JCSystem.lookupAID(ServerAIDbyte,(short) 0,(byte) ServerAIDbyte.length);
        if(ServerAID==null)
            ISOException.throwIt( (short) 0x6A82);
        ////server request
        try{
        sio=(Test_ServerInf)(JCSystem.getAppletShareableInterfaceObject(ServerAID, (byte) 0));
        }
        catch(SecurityException e)
       {
           ISOException.throwIt((short)0x12);
       }
       catch(Exception e)
       {
           ISOException.throwIt((short)0x10);
       }
        if(sio==null)
            ISOException.throwIt((short)0x6A00);

    }

    private void Ins2_Handler(APDU apdu,byte[] apduBuffer){
            Test_ServerInf sio = null;
           ////connect to server  
          ServerAID=JCSystem.lookupAID(ServerAIDbyte,(short) 0,(byte) ServerAIDbyte.length);
           if(ServerAID==null)
                ISOException.throwIt( (short) 0x6A82);
           ////server request
           try{
               sio=(Test_ServerInf)(JCSystem.getAppletShareableInterfaceObject(ServerAID, (byte) 0));
           }
           catch(SecurityException e)
           {
               ISOException.throwIt((short)0x12);
           }
           catch(Exception e)
           {
               ISOException.throwIt((short)0x10);
           }
           if(sio==null)
                ISOException.throwIt((short)0x6A00); 
    }


}

这是服务器小程序代码(Test_Server.java)：

  package server;

import javacard.framework.APDU;
import javacard.framework.Applet;
import javacard.framework.ISOException;
import server.Test_ServerInf;
import javacard.framework.Shareable;
import javacard.framework.AID;

public class Test_Server extends Applet implements Test_ServerInf{


    private Test_Server() {
    }

    public static void install(byte bArray[], short bOffset, byte bLength)
            throws ISOException {
        new Test_Server().register();
    }

    public void process(APDU apdu) throws ISOException {
        // TODO Auto-generated method stub

    }

    public Shareable getShareableInterfaceObject(AID clientAID, byte parameter) {
        return this;
    }

    public short method1(){
        return (short)0x01;
    }
    public short method2(){
        return (short)0x02;
    }

}

和可共享的接口文件(Test_ServerInf.java)：

package server;

import javacard.framework.Shareable;

public interface Test_ServerInf extends Shareable {

    public short method1();
    public short method2();

}

解决方法:

您正在尝试在客户端applet类的成员字段中存储对可共享接口对象的引用：

sio = (Test_ServerInf)(JCSystem.getAppletShareableInterfaceObject(ServerAID, (byte) 0));

其中sio定义为applet类实例的私有成员：

public class Test_Client extends Applet {
    private Test_ServerInf sio;

由于可共享接口对象由服务器小应用程序拥有(即由其他上下文拥有),因此将导致SecurityException.不允许将其他上下文拥有的对象存储在实例字段中.

请参阅《运行时环境规范》(Java卡平台,版本2.2.2)中的“访问类实例对象字段”(第6.2.8.3节)：

Bytecodes: getfield, putfield

• […] if the object is owned by an applet in the currently active context, access is allowed.
• Otherwise, access is denied.