AttachCurrentThread
I'm using the code below.
I successfully create a JVM the first time this is called. And the second time ( and every subsequent time ) this method is invoked, it displays that there is 1 JVM found, but the line:
jint attached = jvm->AttachCurrentThread( (void**)&env, &thr_args );
always returns 0. And when I try to find a class using the env variable it comes back NULL ( although, when first creating the JVM the FindClass method DOES find my class as desired).
Any thoughts ideas would be greatly appreciated.
JavaVM *jvm;
JNIEnv *env;
jint res;
jclass cls;
if ( nVMs == 0 ) {
fprintf(stderr, "No VMs created yet. Creating one now");
JavaVMInitArgs vm_args;
JavaVMOption options[1];
options[0].optionString = "-Djava.class.path=c:/WH";
vm_args.version = JNI_VERSION_1_4;
vm_args.options = options;
vm_args.nOptions = 1;
res = JNI_CreateJavaVM(&jvm, (void**)&env, &vm_args);
if (res < 0) {
fprintf(stderr, "Can't create Java VM\n");
fprintf(stderr, "res:%ld", res );
} else {
fprintf(stderr, "VM created.");
}
if (env->ExceptionOccurred()) {
env->ExceptionDescribe();
}
} else {
JavaVMAttachArgs thr_args;
thr_args.version = JNI_VERSION_1_4;
jint attached = jvm->AttachCurrentThread( (void**)&env, &thr_args );
fprintf(stderr, "AttachCurrentThread: %i", attached);
}
fprintf(stderr, "FindClass com/test/TestMe\n");
cls = env->FindClass("com/test/TestMe");
if (cls == NULL) {
fprintf( stderr, "FindClass returned null ?!?" );
goto destroy;
}
fprintf( stderr, "Found Class !");
Output:
vmError = 0
nVMs = 0
No VMs created yet. Creating one now
VM created.
FindClass com/test/TestMe
Found Class !
vmError = 0
nVMs = 1
AttachCurrentThread: 0
FindClass com/test/TestMe
FindClass returned null ?!?
