Comments by anktrive (Top 8 by date)

The include directives that are missing in the above code
#include jni.h
#include windows.h

Here is the C code file I am trying to compile.

#include <jni.h>
#include <windows.h>

#define PATH_SEPARATOR ';' /* define it to be ':' on Solaris */
#define USER_CLASSPATH "." /* where Prog.class is */

main() {
JNIEnv *env;
JavaVM *jvm;
jint res;
jclass cls;
jmethodID mid;
jstring jstr;
jclass stringClass;
jobjectArray args;

#ifdef JNI_VERSION_1_2
JavaVMInitArgs vm_args;
JavaVMOption options[1];
options[0].optionString =
"-Djava.class.path=" USER_CLASSPATH;
vm_args.version = 0x00010002;
vm_args.options = options;
vm_args.nOptions = 1;
vm_args.ignoreUnrecognized = JNI_TRUE;
/* Create the Java VM */
// this should contain the path to the JVM DLL file
HINSTANCE hVM = LoadLibrary("C:\\Program Files\\Java\\jdk1.6.0_27\\jre6\\bin\\client\\jvm.dll");
if (hVM == NULL)
{
DWORD dwe = GetLastError();
return -1;
}
typedef jint
(CALLBACK *fpCJV)(JavaVM**, void**, JavaVMInitArgs*);

fpCJV CreateJavaVM = (fpCJV)::GetProcAddress(hVM, "JNI_CreateJavaVM");
res = CreateJavaVM(&jvm, (void**)&env, &vm_args);
#else
JDK1_1InitArgs vm_args;
char classpath[1024];
vm_args.version = 0x00010001;
JNI_GetDefaultJavaVMInitArgs(&vm_args);
/* Append USER_CLASSPATH to the 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, &env, &vm_args);
#endif /* JNI_VERSION_1_2 */

if (res < 0) {
fprintf(stderr, "Can't create Java VM\n");
exit(1);
}
cls = (*env)->FindClass(env, "Prog");
if (cls == NULL) {
goto destroy;
}

mid = (*env)->GetStaticMethodID(env, cls, "main",
"([Ljava/lang/String;)V");
if (mid == NULL) {
goto destroy;
}
jstr = (*env)->NewStringUTF(env, " from C!");
if (jstr == NULL) {
goto destroy;
}
stringClass = (*env)->FindClass(env, "java/lang/String");
args = (*env)->NewObjectArray(env, 1, stringClass, jstr);
if (args == NULL) {
goto destroy;
}
(*env)->CallStaticVoidMethod(env, cls, mid, args);

destroy:
if ((*env)->ExceptionOccurred(env)) {
(*env)->ExceptionDescribe(env);
}
(*jvm)->DestroyJavaVM(jvm);
}
Could you please check if it gives any compilation error to you?

The following line gives a compilation error as "syntax error before ':' token "
fpCJV CreateJavaVM = (fpCJV)::GetProcAddress(hVM, "JNI_CreateJavaVM");
Am I missing any import header file?
Sorry for the dumb question but i am new to C programming as well.