testinterface.java

这是一张java应用教程的随书光盘

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("in method run!");	
	}
	public double swim()  {
		System.out.println("in method swim!");
		return 3.14;	
	}
	public int eat() {
		System.out.println("in method eat!");
		return 2000;				
	}
}
public class TestInterface{
	public static void main(String args[]){
		TestInterface t = new TestInterface();
		Person p = new Person();
		t.m1(p);
		t.m2(p);
		t.m3(p);
	}
	public String m1(Runner f) { 
		f.run(); 
		return "ok!";
	}
	public void  m2(Swimmer s) {
		s.swim();
	}
	public void  m3(Animal a) {
		a.eat();
	}
}