HELP IN JNI (1.4) : how to get informations from a jclass pointer ?

Question

Hi,
I am integrating a JVM inside an already built product in C and Objective C. I need to build hash tables of jclass pointers. The problem is :
On two different JNI interactions, when for instance you ask for the jclass pointer of "java/lang/String", you get different pointers. So I cannot built a hash key based on the jclass value. Only
(*env)->IsSameObject(env,jclass1,jclass2) can help to recognize that those pointers points to the same java class.
So it would be usefull for me to grab (efficiently) a stable information, such as the name of the class, to build a hash key from.
Anybody could tell me how can I do this ?
Thanks in advance,
Regards,
C.Dore

Answer 1

Yes, sorry, realized that myself and actually thought I would have posted the correct solution but I guess I forgot about it. Here it is:
import java.util.Hashtable;
public final class Test {
    static { System.loadLibrary("test"); }
    private static native Hashtable  makeHash();
    public static void main(String[] args) {
     Hashtable  h = makeHash();
     h.put("ba", "ba");
     System.out.println(h);
    } // main(String[])
// NATIVE portion:
#include <jni.h>
/* Header for class Test */
#ifdef __cplusplus
extern "C" {
#endif
* Class:     Test
* Method:    makeHash
* Signature: ()Ljava/util/Hashtable;
  JNIEXPORT jobject JNICALL Java_Test_makeHash(JNIEnv *env, jclass klass) {
    jclass    hashClass  = (*env)->FindClass(env, "java/util/Hashtable");
    jmethodID hashConstr = (*env)->GetMethodID(env, hashClass, "<init>", "()V");
    jobject   hash       = (*env)->NewObject(env, hashClass, hashConstr);
    return  hash;
#ifdef __cplusplus
#endif