Java doesn’t support multiple inheritance through class extension, however. When viewing an inheritance hierarchy, you can easily detect multiple inheritance by the presence of a diamond pattern.

Java’s single inheritance limitation is usually not a problem in the normal course of development. In fact, the need to use multiple inheritance could be a sign of a bad design.

However, there's one frustrating limitation: You cannot prevent other developers from extending certain classes. A method might accept a specific type and its subclasses, but you want to restrict ...