1 /* Copyright 2004, 2005, 2006 Acegi Technology Pty Limited
2 *
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16 package org.springframework.security;
17
18 import java.io.Serializable;
19
20 import org.springframework.security.userdetails.UserDetails;
21
22 /**
23 * Represents an authority granted to an {@link Authentication} object.
24 *
25 * <p>
26 * A <code>GrantedAuthority</code> must either represent itself as a
27 * <code>String</code> or be specifically supported by an {@link
28 * AccessDecisionManager}.
29 * </p>
30 *
31 * <p>
32 * Implementations must implement {@link Comparable} in order to ensure that
33 * array sorting logic guaranteed by {@link UserDetails#getAuthorities()} can
34 * be reliably implemented.
35 * </p>
36 *
37 * @author Ben Alex
38 * @version $Id: GrantedAuthority.java 2735 2008-03-16 04:02:55Z benalex $
39 */
40 public interface GrantedAuthority extends Serializable, Comparable {
41 //~ Methods ========================================================================================================
42
43 /**
44 * If the <code>GrantedAuthority</code> can be represented as a <code>String</code> and that
45 * <code>String</code> is sufficient in precision to be relied upon for an access control decision by an {@link
46 * AccessDecisionManager} (or delegate), this method should return such a <code>String</code>.<p>If the
47 * <code>GrantedAuthority</code> cannot be expressed with sufficient precision as a <code>String</code>,
48 * <code>null</code> should be returned. Returning <code>null</code> will require an
49 * <code>AccessDecisionManager</code> (or delegate) to specifically support the <code>GrantedAuthority</code>
50 * implementation, so returning <code>null</code> should be avoided unless actually required.</p>
51 *
52 * @return a representation of the granted authority (or <code>null</code> if the granted authority cannot be
53 * expressed as a <code>String</code> with sufficient precision).
54 */
55 String getAuthority();
56 }