How to get a handle which is used in c dll from javax.smartcardio.card

Question

good afternoon
i am using javax.smartcardio.card to operate a sim-card reader .
but i have a dll which is call sim-card reader by handle.
how can i get a handle from a javax.smartcardio.card object to pass to the dll
next is the code .
c dll prototype declaration
char DoFormat([in] unsigned long P1�C[in] char * P2�C[in] bool P3,[in][out] char *P4)P1 is a handle
java code:
private boolean checkCardReader(boolean isopen)
boolean r=false;
try {
javax.smartcardio.card card;
TerminalFactory factory = TerminalFactory.getDefault();
List terminalList = factory.terminals().list();
terminal = (CardTerminal) terminalList.get(0);
// establish a connection with the card
card = terminal.connect("T=0");
channel = card.getBasicChannel();
//how can i get a handle which can be used by windows dll .
}catch (Exception ex)
System.out.println("Exception : " + ex);
return r;
*****************************************************************

Answer 1

Presumably you are calling a C library method that returns a handle.
Normally a handle will be a integer type value.
With such a value you can cast it into a java integer type and then cast it back in different JNI code by passing it to those routines.
A java long is as big as you can get and will hold most every normal type handle item. You should however verify sizes.