I am trying to invoke a simple helloWorld java method from Objective C via JNI.
The JNI starts, but FindClass returns nil. No class is found, therefore, can't invoke the method.
Please suggest.
My setup:
Java class (located on desktop, compiled with javac)
public class HelloWorld {
public static void main(String[] args) {
System.out.println("Hello, World");
}
}
Objective C
JNIEnv* jniEnv;
JavaVM* javaVM;
- (void)launch {
JavaVMOption javaVMOptions[2];
javaVMOptions[0].optionString = "-Djava.awt.headless=true";
// directory path
javaVMOptions[1].optionString = "-Djava.class.path=/Users/me/Desktop";
JavaVMInitArgs javaVMInitArgs;
javaVMInitArgs.version = JNI_VERSION_1_6;
javaVMInitArgs.options = javaVMOptions;
javaVMInitArgs.nOptions = 1;
javaVMInitArgs.ignoreUnrecognized = JNI_TRUE;
int result = JNI_CreateJavaVM(&javaVM, (void**)&jniEnv, &javaVMInitArgs);
NSLog(@"Java vm launched %i", result);
invoke_class(jniEnv);
}
void invoke_class(JNIEnv* env) {
jclass helloWorldClass;
jmethodID mainMethod;
jobjectArray applicationArgs;
jstring applicationArg0;
helloWorldClass = (*env)->FindClass(env, "HelloWorld");
mainMethod = (*env)->GetStaticMethodID(env, helloWorldClass, "main", "([Ljava/lang/String;)V");
applicationArgs = (*env)->NewObjectArray(env, 1, (*env)->FindClass(env, "java/lang/String"), NULL);
applicationArg0 = (*env)->NewStringUTF(env, "From-C-program");
(*env)->SetObjectArrayElement(env, applicationArgs, 0, applicationArg0);
(*env)->CallStaticVoidMethod(env, helloWorldClass, mainMethod, applicationArgs);
}