sumexample.java

java语言与面向对象程序设计源程序

//SumExample. java
abstract class PhoneCard
    {
      double balance;
      abstract boolean phoneCall ( );
      double getBalance( )
{  return balance ;   
}
};
abstract class Number_PhoneCard extends PhoneCard 
   { 
      long cardNumber;
 int password; 
 boolean connected; 
 Number_PhoneCard( ) 
   {     }; 
     Number_PhoneCard (long cn) 
       { 
this( );
cardNumber = cn; 
        }
 Number_PhoneCard (long cn, int pw ) 
  { 
       this(cn);
       password = pw; 
 } 
 Number_PhoneCard(long cn ,int pw ,double b) 
   { 
this(cn,pw); 
      balance= b;
   } 
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 a)
        {
       super(cn, pw);
       additoryFee = a;
        }
       D200_Card(long cn,int pw,double b,double a)
        {
        super(cn ,pw, b);
        additoryFee = a ;
        }
      boolean phoneCall( ) 
    {
if (! connected) 
       return false ;
if ( balance > (0.4 + additoryFee )) 
       { 
            balance -= (0.4 + additoryFee);
              return true; 
          } 
    else 
           return false ;
  } 
 boolean phoneCall(long cn,int pw) 
 { 
       if (login(cn, pw) )
          return phoneCall ( );
       else 
            return false ;
 } 
 double getBalanee ( )
 { 
     if (connected)
          return balance;
      else 
          return -1 ;
 } 
 public String toString( ) 
 { 
      return ( "电话卡卡号:"+cardNumber 
            +"\n 电话卡密码:"+password
            +"\n 卡中的金额:"+balance 
            +"\n 通话附加费:"+additoryFee); 
  } 
 }
public class SumExample                      //定义主类

   {
     public static void main(String args[])
      {
         D200_Card my200=new D200_Card(43218765, 5658, 50.0, 0.1);
         System.out.println (my200.toString ( ) );
      }
}