private static Field getDeclaredField(Object object, String fieldName) throws NoSuchFieldException {
        Assert.notNull(object);
        return getDeclaredField(object.getClass(), fieldName);
    }
private static Field getDeclaredField ( Object object , String fieldName ) throws NoSuchFieldException { Assert . notNull ( object ) ; return getDeclaredField ( object . getClass ( ) , fieldName ) ; }
循环向上转型,获取对象的DeclaredField.