class FluxBuilder {

    public static boolean isPrimitiveNumber(Class clazz){
        return clazz.isPrimitive() && !clazz.equals(boolean.class);
    }

}

class FluxBuilderTest {

    @Test
    public void testIsPrimitiveNumber() throws Exception {

        assertTrue(FluxBuilder.isPrimitiveNumber(int.class));
        assertFalse(FluxBuilder.isPrimitiveNumber(boolean.class));
        assertFalse(FluxBuilder.isPrimitiveNumber(String.class));
    }

}