1 /*
2 * Copyright 2002-2012 the original author or authors.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package org.springframework.web.bind.support;
18
19 import org.springframework.web.context.request.WebRequest;
20
21 /**
22 * Strategy interface for storing model attributes in a backend session.
23 *
24 * @author Juergen Hoeller
25 * @since 2.5
26 * @see org.springframework.web.bind.annotation.SessionAttributes
27 */
28 public interface SessionAttributeStore {
29
30 /**
31 * Store the supplied attribute in the backend session.
32 * <p>Can be called for new attributes as well as for existing attributes.
33 * In the latter case, this signals that the attribute value may have been modified.
34 * @param request the current request
35 * @param attributeName the name of the attribute
36 * @param attributeValue the attribute value to store
37 */
38 void storeAttribute(WebRequest request, String attributeName, Object attributeValue);
39
40 /**
41 * Retrieve the specified attribute from the backend session.
42 * <p>This will typically be called with the expectation that the
43 * attribute is already present, with an exception to be thrown
44 * if this method returns {@code null}.
45 * @param request the current request
46 * @param attributeName the name of the attribute
47 * @return the current attribute value, or {@code null} if none
48 */
49 Object retrieveAttribute(WebRequest request, String attributeName);
50
51 /**
52 * Clean up the specified attribute in the backend session.
53 * <p>Indicates that the attribute name will not be used anymore.
54 * @param request the current request
55 * @param attributeName the name of the attribute
56 */
57 void cleanupAttribute(WebRequest request, String attributeName);
58
59 }