1 /***
2 * Redistribution and use in source and binary forms, with or without
3 * modification, are permitted provided that the following conditions are
4 * met :
5 *
6 * . Redistributions of source code must retain the above copyright
7 * notice, this list of conditions and the following disclaimer.
8 *
9 * . Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * . The name of the author may not be used to endorse or promote products
14 * derived from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
20 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
22 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
24 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
25 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 *
28 * $Id: ValidationHandler.java,v 1.4 2005/08/26 18:09:36 mat007 Exp $
29 */
30
31 package jtge.engine.security;
32
33 import jtge.engine.command.ICommand;
34 import jtge.engine.handler.AbstractHandler;
35 import jtge.engine.handler.IConsumer;
36 import jtge.engine.user.IUser;
37
38 /***
39 * Implements a handler to filter out invalid commands.
40 * <p>
41 * It intercepts commands and checks that the registered user has the right to issue them before forwarding to the next
42 * consumer.
43 *
44 * @author Mathieu Champlon
45 * @version $Revision: 1.4 $ $Date: 2005/08/26 18:09:36 $
46 */
47 public class ValidationHandler extends AbstractHandler
48 {
49 private final IUser user;
50 private final ISecurityObserver observer;
51
52 /***
53 * Create a validation handler.
54 *
55 * @param consumer the target consumer
56 * @param user the reference user for validation
57 * @param observer the (optional) security observer
58 */
59 public ValidationHandler( final IConsumer consumer, final IUser user, final ISecurityObserver observer )
60 {
61 super( consumer );
62 if( user == null )
63 throw new IllegalArgumentException( "argument 'user' is null" );
64 this.user = user;
65 this.observer = observer;
66 }
67
68 /***
69 * Create a validation handler.
70 *
71 * @param consumer the target consumer
72 * @param user the reference user for validation
73 */
74 public ValidationHandler( final IConsumer consumer, final IUser user )
75 {
76 this( consumer, user, null );
77 }
78
79 /***
80 * {@inheritDoc}
81 */
82 public final void handle( final ICommand command )
83 {
84 if( command == null || command.validate( user ) )
85 forward( command );
86 else if( observer != null )
87 observer.userMismatch( user, command );
88 }
89 }