自己写的JAVA数据结构2

package edu.basejava.util;

import java.util.Iterator;

public class LinkedList<E> implements IList<E>, Iterable<E>
{
 private Link<E> head;

 private Link<E> tail;

 protected Link<E> curr;

 public LinkedList()
 {
  this.setup();
 }

 LinkedList(E[] elements)
 {
  this.setup();
  for (E e : elements)
   this.append(e);
 }

 public void append(E item)
 {
  this.tail.setNext(new Link<E>(item, null));
  this.tail = this.tail.next();

 }

 public void clear()
 {
  this.head.setNext(null);
  this.curr = this.head = this.tail = null;
 }

 public E currValue()
 {
  if (!this.isInList())
  {
   System.err.println("Curr is not in the list");
   return null;
  }

  return this.curr.next().element();
 }

 @SuppressWarnings("unchecked")
 public void insert(E item)
 {
  if (this.curr == null)
  {
   System.err.println("No current element");
   return;
  }
  this.curr.setNext(new Link<E>(item, this.curr.next()));
  if (this.tail == this.curr)
  {
   this.tail = this.curr.next();
  }

 }

 public boolean isEmpty()
 {
  return this.head.next() == null;
 }

 public boolean isInList()
 {

  return (this.curr != null) && (this.curr.next() != null);
 }

 public int length()
 {
  int cnt = 0;
  for (Link<E> tmp = this.head.next(); tmp != null; tmp = tmp.next())
   cnt++;
  return cnt;
 }

 public boolean hasNext()
 {
  return this.curr != null;
 }

 public void next()
 {
  if (this.curr != null)
   this.curr = this.curr.next();

 }

 public void prev()
 {
  if ((this.curr == null) || (this.curr == this.head))
  {
   this.curr = null;
   return;
  }
  Link<E> tmp = this.head;
  while ((tmp != null) && (tmp.next() != this.curr))
   tmp = tmp.next();
  this.curr = tmp;

 }

 public void print()
 {
  if (this.isEmpty())
   System.out.println("()");
  else
  {
   System.out.print("( ");
   for (this.setFirst(); this.isInList(); this.next())
    System.out.print(this.currValue() + " ");
   System.out.println(")");
  }

 }

 public E remove()
 {
  if (!this.isInList())
   return null;
  E it = this.curr.next().element();
  if (this.tail == this.curr.next())
   this.tail = this.curr;
  this.curr.setNext(this.curr.next().next());
  return it;
 }

 public void remove(E element)
 {

  for (this.setFirst(); this.isInList(); this.next())
   if (this.currValue().equals(element))
   {
    this.curr.setNext(this.curr.next().next());
    if (this.curr == this.tail)
    {
     this.curr.setNext(null);
     this.tail = this.curr;
    }
   }
 }

 public void setFirst()
 {
  this.curr = this.head;

 }

 public void setPos(int pos)
 {
  this.curr = this.head;
  for (int i = 0; (this.curr != null) && (i < pos); i++)
   this.curr = this.curr.next();

 }

 public void setValue(E val)
 {
  if (!this.isInList())
  {
   System.err.println("Curr is not in the list");
   return;
  }
  this.curr.next().setElement(val);

 }

 public String toString()
 {
  if (this.isEmpty())
   return ("()");
  StringBuffer sb = new StringBuffer();
  sb.append("( ");
  for (this.setFirst(); this.isInList(); this.next())
   sb.append(this.currValue() + " ");
  sb.append(")");
  return sb.toString();
 }

 private void setup()
 {
  this.tail = this.head = this.curr = new Link<E>(null);
 }

 @SuppressWarnings("hiding")
 private class Link<E>
 {

  private E element;

  private Link<E> next;

  Link(E element, Link<E> next)
  {
   this.element = element;
   this.next = next;
  }

  Link(Link<E> next)
  {
   this.next = next;
  }

  public E element()
  {
   return element;
  }

  public void setElement(E element)
  {
   this.element = element;
  }

  public Link<E> next()
  {
   return next;
  }

  public void setNext(Link<E> next)
  {
   this.next = next;
  }

 }

 public Iterator<E> iterator()
 {
  return new Ite();
 }

 private class Ite implements Iterator<E>
 {

  Ite()
  {
   LinkedList.this.setFirst();
  }

  public void remove()
  {
   throw new UnsupportedOperationException();
  }

  public boolean hasNext()
  {
   LinkedList.this.next();
   return LinkedList.this.hasNext();
  }

  public E next()
  {
   return curr.element();
  }
 }

}