listIterator不工作

Question

我不斷收到一個錯誤：方法listIterator（）對於Salama類型是未定義的。

是否因爲Salama不是LinkedList？

下面的代碼在主：

private Salama asteroids = new Salama(); 
private Salama rockets = new Salama(); 
private Station station = new Station (FrameWidth/2, FrameHeight-20); 

public void paint (Graphics g) { 
    station.paint(g); 

    ListIterator <Faeton> aIt = asteroids.listIterator(); 
    while (aIt.hasNext()) { 
     Faeton asteroid = (Faeton) aIt.next(); 
     asteroid.paint(g); 

這裏從類的：

class Salama {  
    private Object data; 
    private Salama next;  
    private Salama head; 

    Salama(){ 
     head = new Salama(); 
     head.setNext(null); 
     } 

    public void setNext(Salama e) { 
    public Salama getNext() 
    public void setData(Object d) 

    public void add (Object o){ 
     Salama temp = new Salama(); 
     temp.setData(o); 
     Salama current = head; 
     while (current.getNext() != null){ 
      current = current.getNext(); 
     } 
     current.setNext(temp); 
    } 
} 

Answer 1

你Salama類需要listIterator方法（如果你想使用的列表迭代器）。根據您使用的簽名看起來應該像

public ListIterator<Faeton> listIterator() { 
    // Create a list iterator and return here. 
} 

這可能是值得一讀了有關標準ListIterator文檔：http://docs.oracle.com/javase/7/docs/api/java/util/ListIterator.html