Iterator 设计模式

package Iterator;
import java.util.*;
/**实现创建具体迭代器角色的接口， 这个具体迭代器角色与该容器的结构相关**/
public class ConcreteContainer implements Container {
    private Vector vector = null;

    public Vector getVector() {
        return vector;
    }

    public void setVector(Vector vector) {
        this.vector = vector;
    }

    @Override
    public Iterator createIterator() {
        // TODO Auto-generated method stub
        return new ConcreteIterator(vector);
    }

    public ConcreteContainer() {
        vector = new Vector();
        vector.add("vector 1");
        vector.add("vector 2");
        vector.add("vector 3");
    }

}

package Iterator;
/**实现迭代器接口，并要记录遍历中的当前位置**/
import java.util.*;

public class ConcreteIterator implements Iterator {
    private int currentIndex = 0;
    private Vector vector = null;

    public ConcreteIterator(final Vector vector) {
        this.vector = vector;
    }

    @Override
    public Object first() {
        // TODO Auto-generated method stub
        currentIndex = 0;
        return vector.get(currentIndex);
    }

    @Override
    public Object next() {
        // TODO Auto-generated method stub
        currentIndex++;
        return vector.get(currentIndex);
    }

    @Override
    public Object currenItem() {
        // TODO Auto-generated method stub
        return vector.get(currentIndex);
    }

    @Override
    public boolean isDone() {
        // TODO Auto-generated method stub
        if (currentIndex >= this.vector.size() - 1) {
            return true;
        } else {
            return false;
        }
    }

    @Override
    public int count() {
        // TODO Auto-generated method stub
        return 0;
    }

}

package Iterator;
/**负责提供创建具体迭代器角色的接口**/
public interface Container {
    public Iterator createIterator();
}

package Iterator;
/**负责定义访问和遍历元素的接口**/
public interface Iterator {
    public Object first();
    public Object next();
    public Object currenItem();
    public boolean isDone();
    public int count();
}

package JTest;
import static org.junit.Assert.*;

import org.junit.Test;

import Iterator.ConcreteContainer;
import Iterator.Container;
import Iterator.Iterator;

public class IteratorTest {

    @Test
    public void IteratorTest() {
        final Container container = new ConcreteContainer();
        final Iterator iterator = container.createIterator();
        System.out.println(iterator.first());
        while (!iterator.isDone()) {
            System.out.println(iterator.next());
        }
    }

}