问题
org.apache.commons.validator.routines.CodeValidator class of Apache Commons Validator library is presented as "pinned class" icon. What does it mean? I don't see any unusual things it this class.
回答1:
According to this, the "pinned" symbol represents a final Java class. As you can see with the link you provided, the CodeValidator class is, indeed, final.
来源：https://stackoverflow.com/questions/41678343/what-does-pinned-icon-of-a-class-in-intellij-idea-mean