I can't create the JVM using JNI_CreateJavaVM

Question

I'm very much new to the JNI on Windows 2000. When I compiled the example invoke.c program that invoke the java program, it generated invoke.exe file. but when I run the this executable file, it always shows "Can't create Java VM". I tried other samples, but the result is same. I am also sure that I copy jvm.dll from jdk1.2.2\jre\bin\classic to the same folder with invoke.exe file.
I use JDK1.2.2 and Microsoft Visual Studio 6.0 C++. Please let me know what's going on about the following program?
#include <jni.h>
#define USER_CLASSPATH "." /* where Prog.class is */
int main() {
JNIEnv *env;
JavaVM *jvm;
jint res;
jclass cls;
jmethodID mid;
jstring jstr;
jclass stringClass;
jobjectArray args;
JavaVMInitArgs vm_args;
JavaVMOption options[1];
options[0].optionString =
"-Djava.class.path=" USER_CLASSPATH;
vm_args.version = JNI_VERSION_1_2;
vm_args.options = options;
vm_args.nOptions = 1;
vm_args.ignoreUnrecognized = JNI_TRUE;
/* Create the Java VM */
res = JNI_CreateJavaVM(&jvm, (void**)&env, &vm_args);
if (res < 0) {
fprintf(stderr, "Can't create Java VM\n");
exit(1);
cls = (*env)->FindClass(env, "Prog");
if (cls == 0) {
goto destroy;
mid = (*env)->GetStaticMethodID(env, cls, "main",
"([Ljava/lang/String;)V");
if (mid == 0) {
goto destroy;
jstr = (*env)->NewStringUTF(env, " from C!");
if (jstr == 0) {
goto destroy;
stringClass = (*env)->FindClass(env, "java/lang/String");
args = (*env)->NewObjectArray(env, 1, stringClass, jstr);
if (args == 0) {
goto destroy;
(*env)->CallStaticVoidMethod(env, cls, mid, args);
destroy:
if ((*env)->ExceptionOccurred(env)) {
(*env)->ExceptionDescribe(env);
(*jvm)->DestroyJavaVM(jvm);
return 0;

Answer 1

Are you sure you are using the correct jvm.dll?
Remove any jvm.dll files you copied to your .exe directory and set your Path so that is using the jdk1.3 hotspot jvm.dll.
You said you were using windows so the default location of your jdk is C:\jdk1.3.1 To set your path to the correct location use this command:
set Path=%Path%;C:\jdk1.3.1\jre\bin\hotspot
If your jdk is installed somewhere else replace C:\jdk1.3.1 with the root path to your jdk.
If that doesn't work there may be a conflict with the way you compiled the program.