All phones must have a way of making and then terminating a connection to the phone network; however the exact procedure for doing so depends upon the nature of the phone (e.g. landline, cell phone, satellite phone). Write a abstract class, Phone, that contains a string instance variable, phoneNumber, a constructor that accepts a string parameter initializing the instance variable, an accessor method, getPhoneNumber, that returns the phoneNumber, a toString method that return the phoneNumber in the form #(phoneNumber), and two abstract methods: a boolean-valued method named createConnection that returns a boolean and accepts an reference to an object of type Network, and a void-returning method, closeConnection, that accepts no parameters

LANGUAGE: JAVA

CHALLENGE:

All phones must have a way of making and then terminating a connection to the phone network; however the exact procedure for doing so depends upon the nature of the phone (e.g. landline, cell phone, satellite phone). Write a abstract class, Phone, that contains a string instance variable, phoneNumber, a constructor that accepts a string parameter initializing the instance variable, an accessor method, getPhoneNumber, that returns the phoneNumber, a toString method that return the phoneNumber in the form #(phoneNumber), and two abstract methods: a boolean-valued method named createConnection that returns a boolean and accepts an reference to an object of type Network, and a void-returning method, closeConnection, that accepts no parameters

SOLUTION:

public abstract class Phone{
   private String phoneNumber;
   public Phone (String thePhoneNumber) {
      phoneNumber = thePhoneNumber;
   }

   public String getPhoneNumber(){
      return phoneNumber;
   }

   public String toString(){
      phoneNumber = "#(" + phoneNumber + ")";
      return phoneNumber;
   }

   public abstract boolean createConnection(Network status);
   public abstract void closeConnection();
}