Simple win32 JNIEnv problem

Question

I am very new to using jni on windows and am having a C++ compile time problem with a seemingly very simple program. Basically I am trying to do a callback on a java file from my native C++ code. The problem is listed after the following source code excerpts:
<Java file>
class TestJni
     static
          System.loadLibrary("TestJni");
     private native void print();
     public static void main( String [] args )
          new TestJni().print();     
     public void callback()
          System.out.println( "Callback called" );     
<C++ file>
#include <TestJni.h>
#include <iostream.h>
JNIEXPORT void JNICALL Java_TestJni_print( JNIEnv *env, jobject obj )
     cout << "Inside C++" << endl;
     jclass cls = (*env)->GetObjectClass( env, obj );
     jmethodID mid = (*env)->GetMethodId( env, cls, "callback", "()V" );
     if( mid == NULL )
          cout << "Method id was NULL, returning" << endl;
          return;
     (*env)->CallVoidMethod( env, obj, mid );
     return;
Now the actual compile time errors that I am getting from either Visual C++ or command line "cl -I. -IC:\j2sdk1.4.0_01\include -IC:\j2sdk1.4.0_01\include\win32 -MD -LD TestJni.cpp -FeTestJni.dll" are:
d:\java\code\jni_test\testjni.cpp(9) : error C2819: type 'JNIEnv_' does not have an overloaded member 'operator ->'
c:\j2sdk1.4.0_01\include\jni.h(750) : see declaration of 'JNIEnv_'
d:\java\code\jni_test\testjni.cpp(9) : error C2227: left of '->GetObjectClass' must point to class/struct/union
d:\java\code\jni_test\testjni.cpp(10) : error C2819: type 'JNIEnv_' does not have an overloaded member 'operator ->'
c:\j2sdk1.4.0_01\include\jni.h(750) : see declaration of 'JNIEnv_'
d:\java\code\jni_test\testjni.cpp(10) : error C2227: left of '->GetMethodId' must point to class/struct/union
d:\java\code\jni_test\testjni.cpp(18) : error C2819: type 'JNIEnv_' does not have an overloaded member 'operator ->'
c:\j2sdk1.4.0_01\include\jni.h(750) : see declaration of 'JNIEnv_'
d:\java\code\jni_test\testjni.cpp(18) : error C2227: left of '->CallVoidMethod' must point to class/struct/union
Any help would be greatly appreciated. This example is pretty much taken from the book "The Java Native Interface: Programmer Guide and Specification". Thats why I can't understand why it doesn't work.

Answer 1

It was listed this way in the book, honestly. It was almost a complet copy and paste. I would like to know if this is due to the fact that I am on win32 and their are differences between platforms. Do you have any ideas here? It is even a sun certified book, i thought this thing was like the bible for jni.
in the book they always seem to pass env into all the methods, whereas when i looked at jni.h it doesn't expect env because it simply wraps that up for you, for example:
jmethodID GetMethodID(jclass clazz, const char *name,
               const char *sig) {
return functions->GetMethodID(this,clazz,name,sig);
What the hell is going on here, is this book out of date or just plain wrong?