[PDF] Java-Reflection-Tutorial.pdf Dynamic proxy is a class

Can class methods in an abstract class be abstract?

Class methods in an abstract class cannot be abstract. Ø The heading public interface X means X cannot contain anything but non - final instance method headings (with a semicolon in place of the body) and final class variables. A non -abstract object class with the heading class Y implements X must define all methods in that interface .

How does a non-abstract object class implement X?

A non -abstract object class with the heading class Y implements X must define all methods in that interface . A class may implement many interfaces (use implement X,U,Z ) but may subclass only one class. Ø The compiler binds a method call t o a particular method definition when it can, namely, for a class method or for a final instance method.

How do I put abstract in an instance method heading?

You can put abstract in an instance method heading if you replace the method's body by a semicolon. T his makes the class it is in an abstract class. You must also put abstract in the class heading to signal this. Any concrete class that extends the abstract class must have coding for each of the abstract methods.

Can you extend an abstract class with a concrete class?

Any concrete class that extends the abstract class must have coding for each of the abstract methods. Reminder: A method call is polymorphic if at runtime the call could execute any of several different method definitions (i.e., codings). You cannot have an abstract class method, because class methods cannot be overridden.