Java uses “extend” and range resolution / point operators?

I have encountered this problem while reading some code, and I have no idea what it means I tried to use Google search and so on, but I didn't get anything, probably due to lack of vocabulary code:

public final class GeneralPath extends Path2D.Float 
{
    // code and whathaveyou
}

What I know so far:

Therefore, I have no doubt about the "public final class classname extensions", but I don't understand whether there is a point / range resolution operator in the superclass specification First of all, I think someone will say "Java has no range parsing operator" to clarify the subtle difference between Java and CPP / other OOP language, which is good. I'm glad to know this subtle difference The "private" keyword killed me in a HW task. I hope someone will notice the difference between "private" in Java and C

I'm confused because it obviously doesn't refer to the members of the superclass, because the "member" is capitalized. Even if it is, it seems redundant to refer to the members of an object, not just the object class itself In addition, I didn't find any information about this topic, because most people who write java how-to tend to start with simpler concepts, such as "basic" class inheritance, so I can't find anything about the "dot" operator Use the "extends" keyword

If I use too many technical terms, I wonder why they use the dot operator "path2d. Float", or at least what the dot operator does in this context

Thank you so much!

Solution

The generalpath class extends a class float nested in path2d class, which is defined as follows:

public class Path2D {
    public static class Float {
       // ...
    }
    // ...
}