list.java

这是《Java图形用户界面设计与实例》一书配套的源代码

//List.java
//Linked list class, holds URL information


public abstract class List {

    protected WebNode head;
    protected int size = 0;

    public List() {
        head = null;
    }

    public void remove(String s) throws Exception {//Remove URL
        }

    public void add(String url) {//AddURL
        WebNode placeHolder = new WebNode();
        placeHolder.setURL(url);
        placeHolder.setNext(head);
        head=placeHolder;
        size++;
    }

    public String getName(int i) throws Exception{//Returns the name of a URL 
    
        WebNode wn = head;

        if (isEmpty())
            throw new Exception("记录为空");

        for (int x = 0; x < i; x++) {//查找下一个URL,并且返回其值
            wn = wn.getNext();
        }

      return wn.getURL();
    }

    public int getSize() {return size;}//ListSize

    public boolean isEmpty() { return (head == null); }//the list is empty or not



}