Java HotSpot Virtual Machine

I copied jvm.dll to my directory of the project of calling java from within c++. In my c++ code I have statements to test the creation of jvm. I got message: "jni: Can't create Java VM" I do not know what is the problem.

res = JNI_CreateJavaVM(&jvm,(void **)&env,&vm_args);
if (res < 0) {
fprintf(stderr, "jni: Can't create Java VM\n");

The code is :
#include "jni.h"

#ifdef _WIN32
#define PATH_SEPARATOR ';'
#else /* UNIX */
#define PATH_SEPARATOR ':'
#endif

#define USER_CLASSPATH "." /* where MainFrame.class is */

// user classpath


main() {
JNIEnv *env;
JavaVM *jvm;
JDK1_1InitArgs vm_args;
jint res;
jclass cls;
jmethodID mid;
jstring jstr;
jobjectArray args;
char classpath[1024];

printf("\n### welcome to the testprogram ###\n\n");

vm_args.version = 0x00010001;
JNI_GetDefaultJavaVMInitArgs(&vm_args);

/* Append USER_CLASSPATH to the end of default system class path */
sprintf(classpath, "%s%c%s",
vm_args.classpath, PATH_SEPARATOR, USER_CLASSPATH);
vm_args.classpath = classpath;

/* Create the Java VM */
res = JNI_CreateJavaVM(&jvm,(void **)&env,&vm_args);
if (res < 0) {
fprintf(stderr, "jni: Can't create Java VM\n");
// exit(1);
}

cls = env->FindClass("MainFrame");
if (cls == 0) {
fprintf(stderr, "jni: Can't find MainFrame class\n");
// exit(1);
}

mid = env->GetStaticMethodID(cls, "main", "([Ljava/lang/String;)V");
if (mid == 0) {
fprintf(stderr, "jni: Can't find MainFrame.main\n");
// exit(1);
}

jstr = env->NewStringUTF(" from C!");
if (jstr == 0) {
fprintf(stderr, "jni: Out of memory\n");
// exit(1);
}
args = env->NewObjectArray(1, env->FindClass("java/lang/String"), jstr);
if (args == 0) {
fprintf(stderr, "jni: Out of memory\n");
// exit(1);
}
env->CallStaticVoidMethod(cls, mid, args);

jvm->DestroyJavaVM();
}

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