Source of LinkedListGeneric.java

Structures and functions

public class LinkedListGeneric

  1: //LinkedListGeneric.java

  3: import java.util.ArrayList;

  5: public class LinkedListGeneric<E>
  6: {
  7:     private ListNode head;

  9:     public LinkedListGeneric()
 10:     {
 11:         head = null;
 12:     }

 14:     public void showList()
 15:     {
 16:         ListNode position = head;
 17:         while (position != null)
 18:         {
 19:             System.out.println(position.getData());
 20:             position = position.getLink();
 21:         }
 22:     }

 24:     public int length()
 25:     {
 26:         int count = 0;
 27:         ListNode position = head;
 28:         while (position != null)
 29:         {
 30:             count++;
 31:             position = position.getLink();
 32:         }
 33:         return count;
 34:     }

 36:     public void addANodeToStart(E addData)
 37:     {
 38:         head = new ListNode(addData, head);
 39:     }

 41:     public void deleteHeadNode()
 42:     {
 43:         if (head != null)
 44:         {
 45:             head = head.getLink();
 46:         }
 47:         else
 48:         {
 49:             System.out.println("Deleting from an empty list.");
 50:             System.exit(0);
 51:         }
 52:     }

 54:     public boolean onList(E target)
 55:     {
 56:         return find(target) != null;
 57:     }

 59:     private ListNode find(E target)
 60:     {
 61:         boolean found = false;
 62:         ListNode position = head;
 63:         while (position != null)
 64:         {
 65:             E dataAtPosition = position.getData();
 66:             if (dataAtPosition.equals(target))
 67:                 found = true;
 68:             else
 69:                 position = position.getLink();
 70:         }
 71:         return position;
 72:     }

 74:     public ArrayList<E> toArrayList()
 75:     {
 76:                 ArrayList<E> list = new ArrayList<E>(length());
 77:                 ListNode position = head;
 78:                 while (position != null)
 79:                 {
 80:                         list.add(position.data);
 81:                         position = position.link;
 82:                 }
 83:                 return list;
 84:         }

 86:         private class ListNode
 87:         {
 88:                 private E data;
 89:                 private ListNode link;

 91:                 public ListNode()
 92:                 {
 93:                         link = null;
 94:                         data = null;
 95:                 }
 96:                 public ListNode(E newData, ListNode linkValue)
 97:                 {
 98:                         data = newData;
 99:                         link = linkValue;
100:                 }
101:                 public E getData()
102:                 {
103:                         return data;
104:                 }
105:                 public ListNode getLink()
106:                 {
107:                         return link;
108:                 }
109:         }
110: }