java interface的两个经典用法

import CalTime.vehicle.all.Common;
import java .lang.*;
public class ComputeTime {
public static void main(String args[]) {
System.out.println(“交通工具: “+args[0]);
System.out.println(” 参数A: “+args[1]);
System.out.println(” 参数B: “+args[2]);
System.out.println(” 参数C: “+args[3]);
double A=Double.parseDouble(args[1]);
double B=Double.parseDouble(args[2]);
double C=Double.parseDouble(args[3]);
double v,t;
try {
Common d=(Common) Class.forName(“CalTime.vehicle.”+args[0]).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”);
}
}
}

package CalTime.vehicle;
import CalTime.vehicle.all.Common;
public class Plane implements Common {
public double runTimer(double a, double b, double c) {
return (a+ b + c);
}
}

package CalTime.vehicle;
import CalTime.vehicle.all.Common;
public class Car implements Common {
public double runTimer(double a, double b, double c) {
return ( a*b/c );
}
}

package CalTime.vehicle.all;
public interface Common {
double runTimer(double a, double b, double c);
}

interface Extendbroadable{
public void inPut();
}
class KeyBroad   implements Extendbroadable{
public void inPut(){
System.out.println(“\n hi,keybroad has be input into then mainbroad!\n”);
}
}
class NetCardBroad   implements Extendbroadable{
public void inPut(){
System.out.println(“\n hi,netCardBroad has be input into then mainbroad!\n”);
}
}
class CheckBroad{
public void getMainMessage(Extendbroadable ext){
ext.inPut();
}
}
public class InterfaceTest01{
public   static void main(String []args){
KeyBroad kb=new KeyBroad();
NetCardBroad ncb=new NetCardBroad();
CheckBroad cb=new CheckBroad();
cb.getMainMessage(kb);
cb.getMainMessage(ncb);
 
}
}