j3_20.java

来自「本光盘是《JSP应用教程》的配套光盘」· Java 代码 · 共 34 行

interface Runner { 
public void run();
}
interface Swimmer {
public double swim();
}
abstract class Animal  {
abstract public int eat();
} 
class Person extends Animal implements Runner,Swimmer {
	public void run() {
System.out.println("run!");  
}
	public double swim()  {
		double speed = 20;
		return speed;
}
	public int eat() {
		return 3;
}
}
class Test{
	public static void main(String args[]){
		Test t = new Test();
		Person p = new Person();
		t.m1(p);
		t.m2(p);
		t.m3(p);
	}
	public void m1(Runner f) {f.run();}
	public void  m2(Swimmer s) {s.swim();}
	public void  m3(Animal a) {a.eat();}
}