/* 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.providers.dao.salt;

 import org.acegisecurity.AuthenticationServiceException;

 import org.acegisecurity.providers.dao.SaltSource;

 import org.acegisecurity.userdetails.UserDetails;

 import org.springframework.beans.factory.InitializingBean;

 import java.lang.reflect.Method;

 /**

  * Obtains a salt from a specified property of the {@link org.acegisecurity.userdetails.User} object.<P>This allows

  * you to subclass <code>User</code> and provide an additional bean getter for a salt. You should use a synthetic

  * value that does not change, such as a database primary key.  Do not use <code>username</code> if it is likely to

  * change.</p>

  *

  * @author Ben Alex

  * @version $Id: ReflectionSaltSource.java 1519 2006-05-29 15:06:32Z benalex $

  */

 public class ReflectionSaltSource implements SaltSource, InitializingBean {

     //~ Instance fields ================================================================================================

     private String userPropertyToUse;

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

     public void afterPropertiesSet() throws Exception {

         if ((this.getUserPropertyToUse() == null) || "".equals(this.getUserPropertyToUse())) {

             throw new IllegalArgumentException("A userPropertyToUse must be set");

         }

     }

     /**

      * Performs reflection on the passed <code>User</code> to obtain the salt.<P>The property identified by

      * <code>userPropertyToUse</code> must be available from the passed <code>User</code> object. If it is not

      * available, an {@link AuthenticationServiceException} will be thrown.</p>

      *

      * @param user which contains the method identified by <code>userPropertyToUse</code>

      *

      * @return the result of invoking <code>user.userPropertyToUse()</code>

      *

      * @throws AuthenticationServiceException if reflection fails

      */

     public Object getSalt(UserDetails user) {

         try {

             Method reflectionMethod = user.getClass().getMethod(this.userPropertyToUse, new Class[] {});

             return reflectionMethod.invoke(user, new Object[] {});

         } catch (Exception exception) {

             throw new AuthenticationServiceException(exception.getMessage(), exception);

         }

     }

     public String getUserPropertyToUse() {

         return userPropertyToUse;

     }

     /**

      * The method name to call to obtain the salt. If your <code>UserDetails</code> contains a

      * <code>UserDetails.getSalt()</code> method, you should set this property to <code>getSalt</code>.

      *

      * @param userPropertyToUse the name of the <b>getter</b> to call to obtain the salt from the

      *        <code>UserDetails</code>

      */

     public void setUserPropertyToUse(String userPropertyToUse) {

         this.userPropertyToUse = userPropertyToUse;

     }

 }