sir!
   i run the example code of library of
// Example by Tom Igoe
import processing.serial.*;
// The serial port:
Serial myPort;      
// List all the available serial ports:
println(Serial.list());
/*  I know that the first port in the serial list on my mac
is always my  Keyspan adaptor, so I open Serial.list()[0].
Open whatever port is the one you're using.
*/
myPort = new Serial(this, Serial.list()[0], 9600);
// Send a capital A out the serial port:
myPort.write(65);
************************************************
****************************************8
but it tell me
->
java.lang.NoClassDefFoundError: and
Exception in thread "main"

can you tell me why!   thank you!