[Sablevm-user] classpath problems with JNI_CreateJavaVM()

[Tom S. <to...@pl...>]

Hello,
   I am trying to use JNI_CreateJavaVM() to create a JVM, but I am 
having what I think are classpath problems.  The JVM starts ok, but then 
fails to find my class.  Does anyone have any ideas?

Versions:
   gcc            3.3.4-1  The GNU C compiler
   jikes          1.21-2   Fast Java compiler adhering to language and
   jikes-sablevm  1.1.0-5  Wrapper for jikes using classes from SableVM
   sablevm        1.1.0-5  Free implementation of Java Virtual Machine
   libsablevm1-de 1.1.0-5  Free implementation of JVM secon edition - d

Build commands:
   gcc -lsablevm main.c -o main
   jikes-sablevm Foo.java

Running:
   $ ./main
   error finding 'Foo' class
   $

Test files:
/* Foo.java */
public class Foo {
   public static void main(String args[]) {
     System.out.println("Foo::main()");
   }
}


/* main.c */
#include <jni.h>
#include <stdio.h>
int main(int argc, char *argv[]) {
   JavaVMOption options[1];
   JavaVMInitArgs vm_args;
   JNIEnv *env = NULL;
   JavaVM *jvm = NULL;
   jint jni_error;
   jclass java_class;
   jmethodID method_id;

   /* Setup the options list. */
   options[0].optionString = "-Djava.class.path=.";
   options[0].extraInfo = NULL;

   /* Setup the vm_args structure. */
   memset(&vm_args, 0, sizeof(vm_args));
   vm_args.version = JNI_VERSION_1_2;
   vm_args.options = options;
   vm_args.nOptions = sizeof(options) / sizeof(options[0]);

   /* Create the Java Virtual Machine. */
   jni_error = JNI_CreateJavaVM(&jvm, (void **) &env, &vm_args);
   if (jni_error < 0) {
     printf("ERROR: Unable to create JVM, (%i)\n", (int) jni_error);
     return(1);
   }

   /* Get the "Foo" class. */
   java_class = (*env)->FindClass(env, "Foo");
   if (java_class == NULL) {
     printf("error finding 'Foo' class\n");
     return(1);
   }

   /* Get the "main" method ID. */
   method_id = (*env)->GetStaticMethodID(
     env,
     java_class,
     "main",
     "([Ljava/lang/String;)V"
   );
   if (method_id == NULL) {
     printf("error finding 'main' method\n");
     return(1);
   }

   /* Call Foo::main(). */
   (*env)->CallStaticVoidMethod(
     env,
     java_class,
     method_id,
     NULL /* args */
   );

   /* Destroy the VM. */
   (*jvm)->DestroyJavaVM(jvm);

   /* Exit. */
   argc = argc;
   argv = argv;
   return(0);
}

-- 
Tom Schutter (mailto:to...@pl...)
Platte River Associates, Inc. (http://www.platte.com)