Java Tutorial, Third Edition: A Short Course on Note the Previous releases of the Java platform allowed you to use the abstract modifier on Basics, The

interface declarations and on method declarations within interfaces However, this is unnecessary, because interfaces and their methods are implicitly abstract You should not Publisher abstract in your interface declarations or in your method declarations within use : Addison Wesley Pub Date : December 28, 2000 interfacespublic Makes this interface public

ISBN Pages : 0-201-70393-9 : 592

"This book stands above the rest behavior has been available on the interface adheres to the An interface defines a protocol of because it A class that implements anweb and read by thousands of Java programmers The interface To received class that implements an interface, include an protocol defined by that authors have declare a an enormous amount of feedback about which sections implements clause sections are declarationthe confusing ones have been improved I interface (the are good and which in the class confusing; Your class can implement more than one doubt that any Java platform supports multiple such trial byfor interfaces), so the implements keyword is followed by other Java book has undergone inheritance fire" -Metroplex Java User Group, wwwjavamugorg/reviews/ a comma-separated list of the interfaces implemented by the class Whether you're taking a class or learning on the job, The Java(TM) Tutorial, Third Edition , is a handson guide that lets you quickly become proficient with the Java programming language Written by members of the Java Software team at Sun Microsystems, the book uses an interactive approach to By learn the Java help you Convention platform by example SinceTheimplements clausein 1995, the extends in The Java(TM) Tutorial has been updated its first online release follows the material clause, if it exists continuously to reflect reader feedback and new releases of the Java platform This third edition has been thoroughly updated to cover v13 of the Java Platform, Standard Edition, as well as preceding versions as early as JDK 11 Here's a partial example of an applet that implements the StockWatcher interface: You will find clear explanations of such fundamentals as objects, classes, and data structures In addition, the book provides introductions Applet implements StockWatcher { public class StockApplet extends to object-oriented programming, applet construction, and user interface design Other topics include exceptions, I/O, and threads To help beginners avoid many common mistakes, an entire chapter is devoted to programming problems and their solutions public void valueChanged(String tickerSymbol, double newValue) { Convenient summaries at the end of each section are new to this edition Also new for this edition are if (tickerSymbolequals(sunTicker)) { "Questions and Exercises" sections to help you practice what you learn After working through the lessons in this proven tutorial, you will be well prepared to use the Java programming language in your school or workplace } else if (tickerSymbolequals(ciscoTicker)) {

} else if (tickerSymbolequals(oracleTicker)) {

} } }

Note that this class refers to each constant defined in StockWatcher,sunTicker,oracleTicker, andciscoTicker, by its simple name Classes that implement an interface inherit the constants

defined within that interface So those classes can use simple names to refer to the constants Any other class can use an interface's constants with a qualified name, like this:

When a class implements an interface, it is essentially signing a contract Either the class must implement all the methods declared in the interface and its superinterfaces, or the class must be declaredabstract The method signature the name and the number and type of arguments in the class must match the method signature as it appears in the interface The StockApplet implements theStockWatcher interface, so the applet provides an implementation for the valueChanged method The method ostensibly updates the applet's display or otherwise uses this information