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Java Source | 2000-05-25 | 4.1 KB | 123 lines |
- //: Music5.java
- //////////////////////////////////////////////////
- // Copyright (c) Bruce Eckel, 1998
- // Source code file from the book "Thinking in Java"
- // All rights reserved EXCEPT as allowed by the
- // following statements: You can freely use this file
- // for your own work (personal or commercial),
- // including modifications and distribution in
- // executable form only. Permission is granted to use
- // this file in classroom situations, including its
- // use in presentation materials, as long as the book
- // "Thinking in Java" is cited as the source.
- // Except in classroom situations, you cannot copy
- // and distribute this code; instead, the sole
- // distribution point is http://www.BruceEckel.com
- // (and official mirror sites) where it is
- // freely available. You cannot remove this
- // copyright and notice. You cannot distribute
- // modified versions of the source code in this
- // package. You cannot use this file in printed
- // media without the express permission of the
- // author. Bruce Eckel makes no representation about
- // the suitability of this software for any purpose.
- // It is provided "as is" without express or implied
- // warranty of any kind, including any implied
- // warranty of merchantability, fitness for a
- // particular purpose or non-infringement. The entire
- // risk as to the quality and performance of the
- // software is with you. Bruce Eckel and the
- // publisher shall not be liable for any damages
- // suffered by you or any third party as a result of
- // using or distributing software. In no event will
- // Bruce Eckel or the publisher be liable for any
- // lost revenue, profit, or data, or for direct,
- // indirect, special, consequential, incidental, or
- // punitive damages, however caused and regardless of
- // the theory of liability, arising out of the use of
- // or inability to use software, even if Bruce Eckel
- // and the publisher have been advised of the
- // possibility of such damages. Should the software
- // prove defective, you assume the cost of all
- // necessary servicing, repair, or correction. If you
- // think you've found an error, please email all
- // modified files with clearly commented changes to:
- // Bruce@EckelObjects.com. (Please use the same
- // address for non-code errors found in the book.)
- /////////////////////////////////////////////////
-
- // Interfaces
- import java.util.*;
-
- interface Instrument5 {
- // Compile-time constant:
- int i = 5; // static & final
- // Cannot have method definitions:
- void play(); // Automatically public
- String what();
- void adjust();
- }
-
- class Wind5 implements Instrument5 {
- public void play() {
- System.out.println("Wind5.play()");
- }
- public String what() { return "Wind5"; }
- public void adjust() {}
- }
-
- class Percussion5 implements Instrument5 {
- public void play() {
- System.out.println("Percussion5.play()");
- }
- public String what() { return "Percussion5"; }
- public void adjust() {}
- }
-
- class Stringed5 implements Instrument5 {
- public void play() {
- System.out.println("Stringed5.play()");
- }
- public String what() { return "Stringed5"; }
- public void adjust() {}
- }
-
- class Brass5 extends Wind5 {
- public void play() {
- System.out.println("Brass5.play()");
- }
- public void adjust() {
- System.out.println("Brass5.adjust()");
- }
- }
-
- class Woodwind5 extends Wind5 {
- public void play() {
- System.out.println("Woodwind5.play()");
- }
- public String what() { return "Woodwind5"; }
- }
-
- public class Music5 {
- // Doesn't care about type, so new types
- // added to the system still work right:
- static void tune(Instrument5 i) {
- // ...
- i.play();
- }
- static void tuneAll(Instrument5[] e) {
- for(int i = 0; i < e.length; i++)
- tune(e[i]);
- }
- public static void main(String[] args) {
- Instrument5[] orchestra = new Instrument5[5];
- int i = 0;
- // Upcasting during addition to the array:
- orchestra[i++] = new Wind5();
- orchestra[i++] = new Percussion5();
- orchestra[i++] = new Stringed5();
- orchestra[i++] = new Brass5();
- orchestra[i++] = new Woodwind5();
- tuneAll(orchestra);
- }
- } ///:~