原文：
Deprecated. as of 5.3, in favor of hasLength(String) and hasText(String) (or ObjectUtils.isEmpty(Object))
Check whether the given object (possibly a String) is empty. This is effectively a shortcut for !hasLength(String).
This method accepts any Object as an argument, comparing it to null and the empty String. As a consequence, this method will never return true for a non-null non-String object.
The Object signature is useful for general attribute handling code that commonly deals with Strings but generally has to iterate over Objects since attributes may e.g. be primitive value objects as well.
Note: If the object is typed to String upfront, prefer hasLength(String) or hasText(String) instead.
即，自5.3版本起，isEmpty(Object)已建议弃用，使用hasLength(String)或hasText(String)替代。
