Les encoding des types Java (symbolic lookup) :

Element Type Encoding
boolean Z
byte B
char C
double D
float F
int I
long J
short S
class or interface Lclassname;

Exemple : createConsumer(Ljavax/jms/Destination;Ljava/lang/String;Z)Ljavax/jms/MessageConsumer;

see also :
http://docs.oracle.com/javase/6/docs/api/java/lang/Class.html#getName%28%29
http://journals.ecs.soton.ac.uk/java/tutorial/native1.1/implementing/method.html