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 * https://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 */
20 package org.apache.directory.api.ldap.model.message;
21
22
23 import java.util.Observable;
24 import java.util.Observer;
25
26
27 /**
28 * The base abandonable request message class. All such requests have a response
29 * type.
30 *
31 * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a>
32 */
33 public abstract class AbstractAbandonableRequest extends AbstractRequest implements AbandonableRequest
34 {
35 static final long serialVersionUID = -4511116249089399040L;
36
37 /** Flag indicating whether or not this request returns a response. */
38 private boolean abandoned = false;
39
40 /** A filed used to check if the request has been abandonned */
41 private RequestObservable observable;
42
43
44 /**
45 * Subclasses must provide these parameters via a super constructor call.
46 *
47 * @param id the sequential message identifier
48 * @param type the request type enum
49 */
50 protected AbstractAbandonableRequest( final int id, final MessageTypeEnum type )
51 {
52 super( id, type, true );
53 }
54
55
56 /**
57 * {@inheritDoc}
58 */
59 @Override
60 public void abandon()
61 {
62 if ( abandoned )
63 {
64 return;
65 }
66
67 abandoned = true;
68
69 if ( observable == null )
70 {
71 observable = new RequestObservable();
72 }
73
74 observable.setChanged();
75 observable.notifyObservers();
76 observable.deleteObservers();
77 }
78
79
80 /**
81 * {@inheritDoc}
82 */
83 @Override
84 public boolean isAbandoned()
85 {
86 return abandoned;
87 }
88
89
90 /**
91 * {@inheritDoc}
92 */
93 @Override
94 public AbandonableRequest addAbandonListener( final AbandonListener listener )
95 {
96 if ( observable == null )
97 {
98 observable = new RequestObservable();
99 }
100
101 observable.addObserver( new Observer()
102 {
103 @Override
104 public void update( Observable o, Object arg )
105 {
106 listener.requestAbandoned( AbstractAbandonableRequest.this );
107 }
108 } );
109
110 return this;
111 }
112
113 // False positive
114 static class RequestObservable extends Observable
115 {
116 @Override
117 public void setChanged()
118 {
119 super.setChanged();
120 }
121 }
122 }