Does 'extends Object' have a purpose or is it redundant?

Question

Following a tutorial on the internet regarding Soap development with Java, I found this link, with a rather unusual code for myself.

The code:

public         


        

Answer 1

It just means it inherits directly from the Object class. Here is more about inheritance in Java.

Answer 2

No. It's just explicitly doing something that is implicit.

Answer 3

There is one possibility and that is the person who made it don't want you to extend any classes. You can always do a workaround of course but that is the only thing I can come up with that makes sense.

Answer 4

As a matter of fact, it does not seem to be simply redundant, especially when working in the JWS webservices environment.

When defining a class for an XML type to be transported over SOAP, I use the wsimport tool to fetch client dependencies from the WSDL, which creates package-local copies of these classes. By explicitly extending Object, one can seamlessly cast between the classes from the two distinct packages.

Not doing so leads to a compilation error when trying to use a class method from package A that expects an argument type of the class in in package A, and passing in an object generated from the equivalent class in package B.

Answer 5

Why not make it explicit?

I'm for adding it in - not everyone "implicitly" knows that every Java class implicitly extends Object. By writing it explicitly they don't have to guess.

Answer 6

Unless the Object class is not actually the java.lang.Object class (the tutorial does not include the imports, so it's hard to see), the extends Object is redundant.