This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
I was going through some of the excellent mock exams on the Dan Chisholm site and came across a question I need to see some code to understand. The answer indicates that while anonymous classes can not use the implements keyword (which I can understand), they can implement interfaces. Can someone provide a simple example on how you can implement an interface without specifying the interface you are implementing and why you would do so? The only thing I can think of is something like the following (albeit a bit contrived):
In this case, the anonymous class is not using the implements keyword but is implementing the Runnable interface by specifying a method body to the run method.
The best example is when using Gui's, and when creating a button (for example) supplying the implementation of it's ActionListener in an anonymous class using the ActionListener interface from java.awt. Study this code: ----------------------------
Do you understand? Using the ActionPerformed interface in the addActionListener of the button component, i created an anonymous class (implementing the ActionListener interface) to System.out "Button Clicked" and a number each time.