/*

 * JBoss, Home of Professional Open Source

 * Copyright 2011, Red Hat, Inc. and individual contributors

 * by the @authors tag. See the copyright.txt in the distribution for a

 * full listing of individual contributors.

 *

 * This is free software; you can redistribute it and/or modify it

 * under the terms of the GNU Lesser General Public License as

 * published by the Free Software Foundation; either version 2.1 of

 * the License, or (at your option) any later version.

 *

 * This software is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this software; if not, write to the Free

 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA

 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.

 */



package org.openxdm.xcap.server.etag;



import org.openxdm.xcap.common.error.PreconditionFailedException;



public class IfNoneMatchETagValidator implements ETagValidator {



	private String eTag;

	

	public IfNoneMatchETagValidator(String eTag) {		

		this.eTag = eTag;

	}

	

	public void validate(String documentETag) throws PreconditionFailedException {

		if(eTag != null) {

			if(eTag.compareTo("*") == 0) {

				// matches anything except null

				if (documentETag != null) {

					throw new PreconditionFailedException();

				}

			}

			else {

				// etags must not match

				if (documentETag != null && eTag.compareTo(documentETag) == 0) {

					throw new PreconditionFailedException();

				}

			}

		}

	}

	

}