适配器方法惯用法

import java.util.*;

class ReversibleArrayList<T> extends ArrayList<T>{
    public ReversibleArrayList(Collection<T> c) {super(c);}
    public Iterable<T> reversed() {
        return new Iterable<T>() {
            public Iterator<T> iterator() {
                return new Iterator<T>() {
                    int current = size() - 1;
                    public boolean hasNext() {return current > -1;}
                    public T next() {return get(current--);}
                    public void remove() {
                        throw new UnsupportedOperationException();
                    }
                };
            }
        };
    }
}

public class AdapterMethodIdiom {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        ReversibleArrayList<String> ral = new  
                ReversibleArrayList<String>(
                        Arrays.asList("To be or not to be".split(" ")));
        for(String s:ral)
            System.out.print(s+" ");
        System.out.println();
        for(String s:ral.reversed())
            System.out.print(s+" ");
    }


}