ServiceLocationEnumerationImpl.java

/****************************************************************************
 * Copyright (c) 2005, 2010 Jan S. Rellermeyer, Systems Group,
 * Department of Computer Science, ETH Zurich and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Jan S. Rellermeyer - initial API and implementation
 *    Markus Alexander Kuppe - enhancements and bug fixes
 *
*****************************************************************************/
package ch.ethz.iks.slp.impl;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import ch.ethz.iks.slp.ServiceLocationEnumeration;
import ch.ethz.iks.slp.ServiceLocationException;

/**
 * the implementation of a ServiceLocationEnumeration.
 * 
 * @see ch.ethz.iks.slp.ServiceLocationEnumeration
 * @author Jan S. Rellermeyer, IKS, ETH Z�rich
 * @since 0.1
 */
class ServiceLocationEnumerationImpl implements ServiceLocationEnumeration {
	/**
	 * a list of results.
	 */
	private List list;

	/**
	 * internal Iterator over the elements of the list.
	 */
	private Iterator iterator;

	/**
	 * creates a new ServiceLocationEnumerationImpl.
	 * 
	 * @param resultList
	 *            a list of results.
	 */
	ServiceLocationEnumerationImpl(final List resultList) {
		list = resultList != null ? resultList : new ArrayList();
		this.iterator = list.iterator();
	}

	/**
	 * returns the next element of the Enumeration.
	 * 
	 * @return the next element.
	 * @throws ServiceLocationException
	 *             if there is no more element.
	 * @see ch.ethz.iks.slp.ServiceLocationEnumeration#next()
	 */
	public synchronized Object next() throws ServiceLocationException {
		try {
			return iterator.next();
		} catch (Exception e) {
			throw new ServiceLocationException(
					ServiceLocationException.INTERNAL_SYSTEM_ERROR, e
							.getMessage());
		}
	}

	/**
	 * checks if the Enumeration has more elements.
	 * 
	 * @return true if there are more elements available.
	 */
	public synchronized boolean hasMoreElements() {
		return iterator.hasNext();
	}

	/**
	 * returns the next elenemt of the Enumeration.
	 * 
	 * @return the next element or null if there aren't any more.
	 */
	public synchronized Object nextElement() {
		try {
			return next();
		} catch (ServiceLocationException sle) {
			return null;
		}
	}

	public void testMethod() {
		// TODO Auto-generated method stub
		
	}
}