Class not found by FindClass - java-native-interface

Question

I have some troubles with a non-working call to FindClass in my application. I've looked up many questions on this subject but none of these solved my problem...
The JVM creation code:
JavaVM *test_jvm;
JNIEnv *test_jenv;
JavaVMInitArgs vm_args; /* JDK 1.1 VM initialization arguments */
JNI_GetDefaultJavaVMInitArgs(&vm_args);
JavaVMOption options[1];
options[0].optionString = classpath;
vm_args.version = JNI_VERSION_1_4; /* New in 1.1.2: VM version */
vm_args.nOptions = 1;
vm_args.options = options;
vm_args.ignoreUnrecognized = false;
jint ret = JNI_CreateJavaVM(&test_jvm, reinterpret_cast<void**>(&test_jenv), &vm_args);
assert(ret == JNI_OK);
assert(test_jenv->FindClass("my/package/MyClass") != 0);
The definition of classpath:
char classpath[] = "-Djava.class.path=lib/somejar1.jar:"
"bin:"
"lib/somejar2.jar:"
"lib/somejar3.jar";
When I run this code, the assert() code fails, but when I run this (at the same location):
java -cp lib/somejar1.jar:bin:lib/somejar2.jar:lib/somejar3.jar my.package.MyClass
...everything works fine.
The class I am loading is very simple:
package my.package;
public class MyClass {
public static void main(String[] args) {
System.out.println("Hello World!");
}
};
I also tried without the main method but the result was the same. I can load classes from the JARs without issues, but I cannot load this one class from the bin directory...
I have checked many questions, but most of these were about incorrect classpath or incorrect naming convention... I double checked everything and I did not find any issue.
Some other answers mentioned problem with threads, but since I am creating the JVM from a C++ environment, I don't if this apply? And even if it does, this call to FindClass should not be problematic?
I would really appreciate a solution to this, or at least a way to debug in more depth what is happening...

Answer 1

Disclaimer: I found the root of the problem, and I am writting this answer because I did not find a canonical one for FindClass-related problem.
The issue was a difference between the java version of the javac executable used to compile the .java file (Java 1.7, standard Java installation on the machine) and the version of the JNI code (OpenJDK 1.5, custom installation).
Once I compiled the java files with the correct javac executable, the code worked without issue.