magazinelist.java

Java 程序设计教程（第五版）EXAMPLESchap12的程序范例。

//*******************************************************************
//  MagazineList.java       Author: Lewis/Loftus
//
//  Represents a collection of magazines.
//*******************************************************************

public class MagazineList
{
   private MagazineNode list;

   //----------------------------------------------------------------
   //  Sets up an initially empty list of magazines.
   //----------------------------------------------------------------
   public MagazineList()
   {
      list = null;
   }

   //----------------------------------------------------------------
   //  Creates a new MagazineNode object and adds it to the end of
   //  the linked list.
   //----------------------------------------------------------------
   public void add (Magazine mag)
   {

      MagazineNode node = new MagazineNode (mag);
      MagazineNode current;

      if (list == null)
         list = node;
      else
      {
         current = list;
         while (current.next != null)
            current = current.next;
         current.next = node;
      }
   }

   //----------------------------------------------------------------
   //  Returns this list of magazines as a string.
   //----------------------------------------------------------------
   public String toString ()
   {
      String result = "";

      MagazineNode current = list;

      while (current != null)
      {
         result += current.magazine + "\n";
         current = current.next;
      }

      return result;
   }

   //*****************************************************************
   //  An inner class that represents a node in the magazine list.
   //  The public variables are accessed by the MagazineList class.
   //*****************************************************************
   private class MagazineNode
   {
      public Magazine magazine;
      public MagazineNode next;

      //--------------------------------------------------------------
      //  Sets up the node
      //--------------------------------------------------------------
      public MagazineNode (Magazine mag)
      {
         magazine = mag;
         next = null;
      }
   }
}