QtAndroid, exchanging data between c++ and android

[mrdebug]

These are 3 example functions

    public void Test01() {
        System.out.println("Test01");
        System.out.println("Test01");
    }

    public void Test02(int a) {
        System.out.println("Test02");
        System.out.println("Test02");
    }

    public int Test03() {
        System.out.println("Test03");
        System.out.println("Test03");
        return 321;
    }

And that is how I call them

    QtAndroid::androidActivity().callMethod<void>("Test01", "()V");
    QtAndroid::androidActivity().callMethod<void>("Test02", "(I)", 123);
    QtAndroid::androidActivity().callMethod<jint>("Test03", "()V");

Only the first "Test01" works, the second and the third generate the exception

W System.err: java.lang.NoSuchMethodError: no non-static Test02(I)"
W System.err: java.lang.NoSuchMethodError: no non-static Test03()V"

Which kind of mistake am I making?

[mrdebug]

QtAndroid::androidActivity().callMethod<void>("Test02", "(I)V", 123);
QtAndroid::androidActivity().callMethod<jint>("Test03", "()I");

[mvuori]

The method signatures are wrong.
2 should be "(I)V", 3 should be "()I"