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//: polymorphism/music3/Music3.java

// An extensible program.

package polymorphism.music3;

import polymorphism.music.Note;

import static net.mindview.util.Print.*;

class Instrument {

void play(Note n) { print("Instrument.play() " + n); }

String what() { return "Instrument"; }

void adjust() { print("Adjusting Instrument"); }

}

class Wind extends Instrument {

void play(Note n) { print("Wind.play() " + n); }

String what() { return "Wind"; }

void adjust() { print("Adjusting Wind"); }

}

class Percussion extends Instrument {

void play(Note n) { print("Percussion.play() " + n); }

String what() { return "Percussion"; }

void adjust() { print("Adjusting Percussion"); }

}

class Stringed extends Instrument {

void play(Note n) { print("Stringed.play() " + n); }

String what() { return "Stringed"; }

void adjust() { print("Adjusting Stringed"); }

}

class Brass extends Wind {

void play(Note n) { print("Brass.play() " + n); }

void adjust() { print("Adjusting Brass"); }

}

class Woodwind extends Wind {

void play(Note n) { print("Woodwind.play() " + n); }

String what() { return "Woodwind"; }

}

public class Music3 {

// Doesn't care about type, so new types

// added to the system still work right:

public static void tune(Instrument i) {

// ...

i.play(Note.MIDDLE_C);

}

public static void tuneAll(Instrument[] e) {

for(Instrument i : e)

tune(i);

}

public static void main(String[] args) {

// Upcasting during addition to the array:

Instrument[] orchestra = {

new Wind(),

new Percussion(),

new Stringed(),

new Brass(),

new Woodwind()

};

tuneAll(orchestra);

}

} /* Output:

Wind.play() MIDDLE_C

Percussion.play() MIDDLE_C

Stringed.play() MIDDLE_C

Brass.play() MIDDLE_C

Woodwind.play() MIDDLE_C

*///:~