java接口示例

接口示例

package auto.test;


public class RerridingTest {
    public static void main(String args[]){

    test("Car","100","45","67" );
    test("Plane","100","45","67" );
    test("Bike","100","45","67" );
    
    }

    public static void test(String tool, String a,String b, String c) {
        System.out.println("交通工具: " + tool);
        System.out.println(" 参数A: " + a);
        System.out.println(" 参数B: " + b);
        System.out.println(" 参数C: " + c);
        double A = Double.parseDouble(a);
        double B = Double.parseDouble(b);
        double C = Double.parseDouble(c);
        double v, t;
        try {
            Common d = (Common) Class.forName("auto.test." + tool).newInstance();
            v = d.runTimer(A, B, C);
            t = 1000 / v;
            System.out.println("平均速度: " + v + " km/h");
            System.out.println("运行时间：" + t + " 小时");
        } catch (Exception e) {
            System.out.println("class not found");
        }
    }
}

class Plane implements Common {
    public double runTimer(double a, double b, double c) {
        return (a + b + c);
    }
}

class Car implements Common {
    public double runTimer(double a, double b, double c) {
        return (a * b / c);
    }
}


class Bike implements Common {
    public double runTimer(double a, double b, double c) {
        return ((a+b+c)*2);
    }
}
interface Common {
    double runTimer(double a, double b, double c);
}

示例二

package auto.test;
//1、先建一个动物接口，接口里面有吃的方法，没有方法体
interface Animal {
    public void eat();

}
//2 建一个狗的类，implements 动物类，Animal
class Dog implements Animal{
    public void eat(){  //重写animal的eat 方法
        System.out.println("eat bone");
    }
}
//3 建一个猫的类，implements 动物类，Animal
class Cat implements Animal{
    public void eat(){//重写animal的eat 方法
        System.out.println("eat fish");
    }
}
//统一处理所有animal 类的行为
class TestInterface{
    public void getEat(Animal a){// 传入动物类
        a.eat();
    }
}
//测试类
class TestAnimal{
    public static void main(String arg[]){
        Dog d = new Dog(); 
        Cat c = new Cat();
        TestInterface te = new TestInterface();
        te.getEat(d);
        te.getEat(c);        
    }    
}

来源：http://blog.sina.com.cn/s/blog_48c0812c0101alaz.html