/* Copyright 2004, 2005, 2006 Acegi Technology Pty Limited

  *

  * 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.acegisecurity.ui;

 import org.acegisecurity.AuthenticationException;

 import java.io.IOException;

 import javax.servlet.ServletException;

 import javax.servlet.ServletRequest;

 import javax.servlet.ServletResponse;

 /**

  * Used by {@link ExceptionTranslationFilter} to commence an authentication

  * scheme.

  *

  * @author Ben Alex

  * @version $Id: AuthenticationEntryPoint.java 1784 2007-02-24 21:00:24Z luke_t $

  */

 public interface AuthenticationEntryPoint {

     //~ Methods ========================================================================================================

     /**

      * Commences an authentication scheme.<P><code>SecurityEnforcementFilter</code> will populate the

      * <code>HttpSession</code> attribute named

      * <code>AuthenticationProcessingFilter.ACEGI_SECURITY_TARGET_URL_KEY</code> with the requested target URL before

      * calling this method.</p>

      *  <P>Implementations should modify the headers on the <code>ServletResponse</code> as necessary to

      * commence the authentication process.</p>

      *

      * @param request that resulted in an <code>AuthenticationException</code>

      * @param response so that the user agent can begin authentication

      * @param authException that caused the invocation

      *

      * @throws IOException DOCUMENT ME!

      * @throws ServletException DOCUMENT ME!

      */

     void commence(ServletRequest request, ServletResponse response, AuthenticationException authException)

         throws IOException, ServletException;

 }