vecterator.java

来自「《Java与模式》一书的源代码」· Java 代码 · 共 48 行

package com.javapatterns.iterator.vecterator2;

import java.util.NoSuchElementException;
import java.util.Vector;

public class Vecterator
{
    private Vector iteratee;
    private int count;

    public Vecterator(Vector v)
    {
        iteratee = (Vector)v.clone();
        count = 0;
    }

    public void first()
    {
        count = 0;
    }

    public boolean isDone()
    {
        return count < iteratee.size();
    }

    public void next()
    {
        if (count < iteratee.size())
        {
            count++;
        }
    }

    public Object currentItem()
    {
        synchronized(iteratee)
        {
            if (count < iteratee.size())
            {
                return iteratee.elementAt(count);
            }
        }
        throw new NoSuchElementException("Vecterator");
    }

}