ChainedList.java

/*
 * Copyright (c) 2012 EMC Corporation
 * All Rights Reserved
 */

package com.emc.storageos.api.service.impl.resource;

import java.util.*;

/**
 * Used for chaining two iterators
 */
public class ChainedList<T> implements List<T> {
    private final Iterator<Iterator<T>> _iterators;
    private ChainedIterator _chained;

    private class ChainedIterator implements Iterator<T> {
        private Iterator<T> _currentIt = _iterators.next();

        @Override
        public boolean hasNext() {

            if (_currentIt.hasNext()) {
                return true;
            }

            while (_iterators.hasNext()) {
                _currentIt = _iterators.next();
                if (_currentIt.hasNext()) {
                    return true;
                }
            }
            return false;
        }

        @Override
        public T next() {
            return _currentIt.next();
        }

        @Override
        public void remove() {
            throw new UnsupportedOperationException();
        }
    }

    public ChainedList(Iterator<T>... iterator) {
        _iterators = Arrays.asList(iterator).iterator();
        _chained = new ChainedIterator();
    }

    @Override
    public int size() {
        throw new UnsupportedOperationException();
    }

    @Override
    public boolean isEmpty() {
        throw new UnsupportedOperationException();
    }

    @Override
    public boolean contains(Object o) {
        throw new UnsupportedOperationException();
    }

    @Override
    public Iterator<T> iterator() {
        return _chained;
    }

    @Override
    public Object[] toArray() {
        throw new UnsupportedOperationException();
    }

    @Override
    public <T> T[] toArray(T[] a) {
        throw new UnsupportedOperationException();
    }

    @Override
    public boolean add(T t) {
        throw new UnsupportedOperationException();
    }

    @Override
    public boolean remove(Object o) {
        throw new UnsupportedOperationException();
    }

    @Override
    public boolean containsAll(Collection<?> c) {
        throw new UnsupportedOperationException();
    }

    @Override
    public boolean addAll(Collection<? extends T> c) {
        throw new UnsupportedOperationException();
    }

    @Override
    public boolean addAll(int index, Collection<? extends T> c) {
        throw new UnsupportedOperationException();
    }

    @Override
    public boolean removeAll(Collection<?> c) {
        throw new UnsupportedOperationException();
    }

    @Override
    public boolean retainAll(Collection<?> c) {
        throw new UnsupportedOperationException();
    }

    @Override
    public void clear() {
        throw new UnsupportedOperationException();
    }

    @Override
    public T get(int index) {
        throw new UnsupportedOperationException();
    }

    @Override
    public T set(int index, T element) {
        throw new UnsupportedOperationException();
    }

    @Override
    public void add(int index, T element) {
        throw new UnsupportedOperationException();
    }

    @Override
    public T remove(int index) {
        throw new UnsupportedOperationException();
    }

    @Override
    public int indexOf(Object o) {
        throw new UnsupportedOperationException();
    }

    @Override
    public int lastIndexOf(Object o) {
        throw new UnsupportedOperationException();
    }

    @Override
    public ListIterator<T> listIterator() {
        throw new UnsupportedOperationException();
    }

    @Override
    public ListIterator<T> listIterator(int index) {
        throw new UnsupportedOperationException();
    }

    @Override
    public List<T> subList(int fromIndex, int toIndex) {
        throw new UnsupportedOperationException();
    }
}