I wrote the following program to return all the APDU buffer contents on reception of each APDU command:
package testPack;
import javacard.framework.APDU;
import javacard.framework.Applet;
import javacard.framework.ISOException;
public class BufferReturner extends Applet {
private BufferReturner() {
}
public static void install(byte bArray[], short bOffset, byte bLength) throws ISOException {
new BufferReturner().register();
}
public void process(APDU arg0) throws ISOException {
if(selectingApplet()){
return;
}
arg0.setOutgoingAndSend((short)0, (short)255);
}
}
When I send commands though the contact interface using T=0 protocol, I receive the following result:
Connect successful. Send: 00 A4 04 00 06 01 02 03 04 05 00 00 Recv: 90 00 Time used: 8.000 ms Send: 00 00 00 00 10 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 00 Send Apdu error: A device attached to the system is not functioning. Send: 00 00 00 00 10 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 00 Recv: 6C FF Time used: 5.000 ms Send: 00 00 00 00 10 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 FF Recv: 6C FF Time used: 5.000 ms Send: 00 00 00 00 10 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 FF Recv: 6C FF Time used: 5.000 ms Send: 00 00 00 00 10 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 FF Recv: 6C FF Time used: 6.000 ms Send: 00 C0 00 00 FF Send Apdu error: A device attached to the system is not functioning. Send: 00 C0 00 00 FF Send Apdu error: A device attached to the system is not functioning.
As you see I can't receive the APDU buffer contents. What's wrong?
Just like with Transmission error for T=0 JavaCards there is nothing wrong with your card and this is kind of "expected" behavior.
For the setOutgoing() method (setOutgoingAndSend() is just a convenience method wrapping setOutgoing()), the Java Card API specification clearly states:
On a case 4 command, the
setIncomingAndReceive()must be invoked prior to calling this method. Otherwise, erroneous behavior may result in T=0 protocol.
Hence, what you see is exactly that "erroneous behavior" indicated in the API specification.
来源：https://stackoverflow.com/questions/35042941/why-i-cant-receive-apdu-buffer-contents