View Javadoc

1   /*
2   * Copyright 2004 The Apache Software Foundation
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  package javax.servlet;
17  
18  import java.util.EventListener;
19  
20      /**
21       * A ServletRequestAttributeListener can be implemented by the
22       * developer interested in being notified of request attribute
23       * changes. Notifications will be generated while the request
24       * is within the scope of the web application in which the listener
25       * is registered. A request is defined as coming into scope when
26       * it is about to enter the first servlet or filter in each web
27       * application, as going out of scope when it exits the last servlet
28       * or the first filter in the chain.
29       *
30       * @since Servlet 2.4
31       */
32  
33  public interface ServletRequestAttributeListener extends EventListener {
34      /** Notification that a new attribute was added to the
35       ** servlet request. Called after the attribute is added.
36       */
37      public void attributeAdded(ServletRequestAttributeEvent srae);
38  
39      /** Notification that an existing attribute has been removed from the
40       ** servlet request. Called after the attribute is removed.
41       */
42      public void attributeRemoved(ServletRequestAttributeEvent srae);
43  
44      /** Notification that an attribute was replaced on the
45       ** servlet request. Called after the attribute is replaced.
46       */
47      public void attributeReplaced(ServletRequestAttributeEvent srae);
48  }
49