匿名内部类 , Iterable<T> 和 Iterator<T>
package generic; import java.util.ArrayList; import java.util.Arrays; import java.util.Collection; import java.util.Iterator; public class ReversibleArrayList<T> extends ArrayList<T> { private static final long serialVersionUID = -2293646393609696016L; public ReversibleArrayList(Collection<T> collection){ super(collection); } public Iterable<T> reversed(){ return new Iterable<T>() { @Override public Iterator<T> iterator() { return new Iterator<T>() { int idx = ReversibleArrayList.this.size() - 1; @Override public boolean hasNext() { return idx > -1; } @Override public T next() { return ReversibleArrayList.this.get(idx--); } @Override public void remove() { throw new UnsupportedOperationException(); } }; } }; } public static void main(String[] args) { ReversibleArrayList<String> list = new ReversibleArrayList<String>( Arrays.asList("To be or not to be".split(" "))); for (String s : list) { System.out.println(s); } System.out.println("----------------"); for (String s : list.reversed()) { System.out.println(s); } } }