java完全限定名是什么

Answer 1

Give me an example:

我的一个类里面引入了：

import org.apache.commons.lang3.StringUtils;

At this time, my class can use the methods in the StringUtils class:

boolean isEmpty = StringUtils.isNotEmpty(str);

That’s right, you can directly use the method in it.

Then suppose that I want to use the methods in StringUtils provided by spring in this class, but I do not import spring's StringUtils class. What should I do at this time? We can do this (provided there is a spring jar):

boolean isEmpty = org.springframework.util.StringUtils.isEmpty(str);

That’s right, it’s the fully qualified name to access spring’s StringUtils class.

This is my understanding, any corrections are welcome.

Answer 2

Just check JLS for this kind of problem
6.7. Fully Qualified Names and Canonical Names