/*
 * Copyright 2013-2014 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations under the License.
 */

package org.springframework.security.oauth2.provider.authentication;

import javax.servlet.http.HttpServletRequest;

import org.springframework.security.core.Authentication;

/**
 * @author Dave Syer
 *
 */
public interface TokenExtractor {

	/**
	 * Extract a token value from an incoming request without authentication.
	 * 
	 * @param request the current ServletRequest
	 * @return an authentication token whose principal is an access token (or null if there is none)
	 */
	Authentication extract(HttpServletRequest request);

}