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.providers.dao;
17
18 import org.springframework.security.userdetails.User;
19 import org.springframework.security.userdetails.UserDetails;
20
21
22 /**
23 * Provides a cache of {@link User} objects.
24 *
25 * <P>
26 * Implementations should provide appropriate methods to set their cache
27 * parameters (eg time-to-live) and/or force removal of entities before their
28 * normal expiration. These are not part of the <code>UserCache</code>
29 * interface contract because they vary depending on the type of caching
30 * system used (eg in-memory vs disk vs cluster vs hybrid).
31 * </p>
32 *
33 * @author Ben Alex
34 * @version $Id: UserCache.java 2217 2007-10-27 00:45:30Z luke_t $
35 */
36 public interface UserCache {
37 //~ Methods ========================================================================================================
38
39 /**
40 * Obtains a {@link UserDetails} from the cache.
41 *
42 * @param username the {@link User#getUsername()} used to place the user in the cache
43 *
44 * @return the populated <code>UserDetails</code> or <code>null</code> if the user could not be found or if the
45 * cache entry has expired
46 */
47 UserDetails getUserFromCache(String username);
48
49 /**
50 * Places a {@link UserDetails} in the cache. The <code>username</code> is the key used to subsequently
51 * retrieve the <code>UserDetails</code>.
52 *
53 * @param user the fully populated <code>UserDetails</code> to place in the cache
54 */
55 void putUserInCache(UserDetails user);
56
57 /**
58 * Removes the specified user from the cache. The <code>username</code> is the key used to remove the user.
59 * If the user is not found, the method should simply return (not thrown an exception).<P>Some cache
60 * implementations may not support eviction from the cache, in which case they should provide appropriate
61 * behaviour to alter the user in either its documentation, via an exception, or through a log message.</p>
62 *
63 * @param username to be evicted from the cache
64 */
65 void removeUserFromCache(String username);
66 }