hunt.shiro.mgt.SessionStorageEvaluator source code

1 /*
2  * Licensed to the Apache Software Foundation (ASF) under one
3  * or more contributor license agreements.  See the NOTICE file
4  * distributed with this work for additional information
5  * regarding copyright ownership.  The ASF licenses this file
6  * to you under the Apache License, Version 2.0 (the
7  * "License"); you may not use this file except in compliance
8  * with the License.  You may obtain a copy of the License at
9  *
10  *     http://www.apache.org/licenses/LICENSE-2.0
11  *
12  * Unless required by applicable law or agreed to in writing,
13  * software distributed under the License is distributed on an
14  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15  * KIND, either express or implied.  See the License for the
16  * specific language governing permissions and limitations
17  * under the License.
18  */
19 module hunt.shiro.mgt.SessionStorageEvaluator;
20 
21 import hunt.shiro.subject.Subject;
22 
23 /**
24  * Evaluates whether or not Shiro may use a {@code Subject}'s {@link hunt.shiro.session.Session Session}
25  * to persist that {@code Subject}'s internal state.
26  * <p/>
27  * It is a common Shiro implementation strategy to use a Subject's session to persist the Subject's identity and
28  * authentication state (e.g. after login) so that information does not need to be passed around for any further
29  * requests/invocations.  This effectively allows a session id to be used for any request or invocation as the only
30  * 'pointer' that Shiro needs, and from that, Shiro can re-create the Subject instance based on the referenced Session.
31  * <p/>
32  * However, in purely stateless applications, such as some REST applications or those where every request is
33  * authenticated, it is usually not needed or desirable to use Sessions to store this state (since it is in
34  * fact re-created on every request).  In these applications, sessions would never be used.
35  * <p/>
36  * This interface allows implementations to determine exactly when a Session might be used or not to store
37  * {@code Subject} state on a <em>per-Subject</em> basis.
38  * <p/>
39  * If you simply wish to enable or disable session usage at a global level for all {@code Subject}s, the
40  * {@link DefaultSessionStorageEvaluator} should be sufficient.  Per-subject behavior should be performed in custom
41  * implementations of this interface.
42  *
43  * @see Subject#getSession()
44  * @see Subject#getSession(bool)
45  * @see DefaultSessionStorageEvaluator
46  */
47 interface SessionStorageEvaluator {
48 
49     /**
50      * Returns {@code true} if the specified {@code Subject}'s
51      * {@link hunt.shiro.subject.Subject#getSession() session} may be used to persist that Subject's
52      * state, {@code false} otherwise.
53      *
54      * @param subject the {@code Subject} for which session state persistence may be enabled
55      * @return {@code true} if the specified {@code Subject}'s
56      *         {@link hunt.shiro.subject.Subject#getSession() session} may be used to persist that Subject's
57      *         state, {@code false} otherwise.
58      * @see Subject#getSession()
59      * @see Subject#getSession(bool)
60      */
61     bool isSessionStorageEnabled(Subject subject);
62 
63 }