reload.java

来自「java语言与面向对象程序设计源程序」· Java 代码 · 共 75 行

abstract class PhoneCard
        {
           double balance ;   
           abstract boolean phoneCall ( ) ;
           double getBalance ( )               
             {
               return balance ;
             }
        }
abstract class Number_PhoneCard extends PhoneCard
   {
        long cardNumber ;
        int password ;
        boolean connected ;
      boolean  login(long cn,int pw)
         {
            if  (cn == cardNumber && pw == password)
              {
                  connected = true ;
                  return true ;
              }
            else
                  return false ;
         }
    }
class D200_Card extends Number_PhoneCard
    {
double additoryFee; 
D200_Card (long cn, int pw, double b )
 {
           cardNumber = cn ;
           password = pw;
           balance = b ;
} 
     boolean phoneCall ( )                    //已连接情况下的拨打电话
        { 
if (! connected )
                return false ;
           if  ( balance > (0.4 +additoryFee )) 
            { 
              balance -= (0.4 +additoryFee) ; 
                 return true; 
            } 
           else 
                return  false; 
}
boolean phoneCall (long cn, int pw )          //未连接情况下的拨打电话
        { 
if (login(cn,pw) )
                return  phoneCall ();
           else 
                return  false;
       }
    double getBalance()
{
if (connected)
   return balance;
else
   return -1;
}
}
public  class  reload                            // 主类定义
      {
    public static void main(String args[])
        {    
          D200_Card my200=new D200_Card(43215678,5645,50.0);
            if (my200. phoneCall (43215678,5645) )       //调用第二个phoneCall方法
             System.out.println("拨打电话后剩余金额为；"+my200.getBalance());
            if (my200. phoneCall () )                   //调用第一个phoneCall方法
             System.out.println("拨打电话后剩余金额为："+my200.getBalance()) ;
      }
}