java - javac "no source files" when using -h option

Question

I'm trying to experiment with using the JNI and JDK 9. I have a class NativeTest.java that looks like this:

public class NativeTest {

    static {
        System.loadLibrary("hello");
    }

    private native void sayHello();

    public static void main(String[] args) {
        new NativeTest().sayHello();
    }
}

I compile the class, then use javah NativeTest to generate the header file.

Upon issuing javah, I get this warning:

Warning: The javah tool is planned to be removed in the next major
JDK release. The tool has been superseded by the '-h' option added
to javac in JDK 8. Users are recommended to migrate to using the
javac '-h' option; see the javac man page for more information.

I know it'll be quite a while before the next major JDK release, but I figured I'd start getting used to this new option now.

So upon trying javac -h NativeTest.java (and other variations like NativeTest, NativeTest.class, etc.) I keep getting this error:

javac: no source files

I haven't been able to find any help online, probably because this feature is relatively new, and I can't find anything about this new -h option in the man page.

Anyone else try this yet? What am I missing?

Answer 1

The solution I discovered was that I was not specifying the directory where javac should place the header files.

Executing javac -h . NativeTest.java worked.