?? music10.java
字號(hào):
// interfaces/music10/Music10.java
// TIJ4 Chapter Interfaces, Exercise 10, page 320
/* Modify Music5.java by adding a Playable interface. Move the play() declaration
* from Instrument to Playable. Add Playable to the derived classes by including
* it in the implements list. Change tune() so that it takes a Playable instead
* of and Instrument.
*/
package interfaces.music10;
import polymorphism.music.Note;
import static net.mindview.util.Print.*;
interface Instrument {
// Compile-time constant:
int VALUE = 5; // static and final
// Cannot have method definitions:
void adjust();
}
interface Playable {
void play(Note n); // Automatically public
}
class Wind implements Instrument, Playable {
public void play(Note n) {
print(this + ".play() " + n);
}
public String toString() { return "Wind"; }
public void adjust() { print(this + ".adjust()"); }
}
class Percussion implements Instrument, Playable {
public void play(Note n) {
print(this + ".play() " + n);
}
public String toString() { return "Percussion"; }
public void adjust() { print(this + ".adjust()"); }
}
class Stringed implements Instrument, Playable {
public void play(Note n) {
print(this + ".play() " + n);
}
public String toString() { return "Stringed"; }
public void adjust() { print(this + ".adjust()"); }
}
class Brass extends Wind {
public String toString() { return "Brass"; }
}
class Woodwind extends Wind {
public String toString() { return "Woodwing"; }
}
public class Music10 {
// Doesn't care about type, so new types
// added to the system will work right:
static void tune(Playable p) {
//...
p.play(Note.MIDDLE_C);
}
static void tuneAll(Playable[] e) {
for(Playable p : e)
tune(p);
}
public static void main(String[] args) {
// Upcasting during addition to the array:
Playable[] orchestra = {
new Wind(),
new Percussion(),
new Stringed(),
new Brass(),
new Woodwind()
};
tuneAll(orchestra);
}
}
?? 快捷鍵說(shuō)明
復(fù)制代碼
Ctrl + C
搜索代碼
Ctrl + F
全屏模式
F11
切換主題
Ctrl + Shift + D
顯示快捷鍵
?
增大字號(hào)
Ctrl + =
減小字號(hào)
Ctrl + -