KickJava   Java API By Example, From Geeks To Geeks.

Java > Open Source Codes > org > ungoverned > oscar > util > ServiceListenerWrapper


1 /*
2  * Oscar - An implementation of the OSGi framework.
3  * Copyright (c) 2004, Richard S. Hall
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * * Redistributions of source code must retain the above copyright
11  * notice, this list of conditions and the following disclaimer.
12  * * Redistributions in binary form must reproduce the above copyright
13  * notice, this list of conditions and the following disclaimer in
14  * the documentation and/or other materials provided with the
15  * distribution.
16  * * Neither the name of the ungoverned.org nor the names of its
17  * contributors may be used to endorse or promote products derived
18  * from this software without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
21  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
23  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
24  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
25  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
26  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
30  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31  *
32  * Contact: Richard S. Hall (heavy@ungoverned.org)
33  * Contributor(s):
34  *
35 **/

36 package org.ungoverned.oscar.util;
37
38 import java.security.AccessControlContext JavaDoc;
39 import java.security.AccessController JavaDoc;
40 import java.security.PrivilegedAction JavaDoc;
41
42 import org.osgi.framework.*;
43
44 public class ServiceListenerWrapper extends ListenerWrapper implements ServiceListener
45 {
46     // LDAP query filter.
47
private Filter m_filter = null;
48     // Remember the security context.
49
private AccessControlContext JavaDoc m_acc = null;
50
51     public ServiceListenerWrapper(Bundle bundle, ServiceListener l, Filter filter)
52     {
53         super(bundle, ServiceListener.class, l);
54         m_filter = filter;
55
56         // Remember security context for filtering
57
// events based on security.
58
if (System.getSecurityManager() != null)
59         {
60             m_acc = AccessController.getContext();
61         }
62     }
63
64     public void setFilter(Filter filter)
65     {
66         m_filter = filter;
67     }
68     
69     public void serviceChanged(final ServiceEvent event)
70     {
71         // Service events should be delivered to STARTING,
72
// STOPPING, and ACTIVE bundles.
73
if ((getBundle().getState() != Bundle.STARTING) &&
74             (getBundle().getState() != Bundle.STOPPING) &&
75             (getBundle().getState() != Bundle.ACTIVE))
76         {
77             return;
78         }
79
80         // Check that the bundle has permission to get at least
81
// one of the service interfaces; the objectClass property
82
// of the service stores its service interfaces.
83
ServiceReference ref = event.getServiceReference();
84         String JavaDoc[] objectClass = (String JavaDoc[]) ref.getProperty(Constants.OBJECTCLASS);
85
86         // On the safe side, if there is no objectClass property
87
// then ignore event altogether.
88
if (objectClass != null)
89         {
90             boolean hasPermission = false;
91             if (m_acc != null)
92             {
93                 for (int i = 0;
94                     !hasPermission && (i < objectClass.length);
95                     i++)
96                 {
97                     try {
98                         ServicePermission perm =
99                             new ServicePermission(
100                                 objectClass[i], ServicePermission.GET);
101                         m_acc.checkPermission(perm);
102                         hasPermission = true;
103                     } catch (Exception JavaDoc ex) {
104                     }
105                 }
106             }
107             else
108             {
109                 hasPermission = true;
110             }
111
112             if (hasPermission)
113             {
114                 // Dispatch according to the filter.
115
if ((m_filter == null) || m_filter.match(event.getServiceReference()))
116                 {
117                     if (System.getSecurityManager() != null)
118                     {
119                         AccessController.doPrivileged(new PrivilegedAction JavaDoc() {
120                             public Object JavaDoc run()
121                             {
122                                 ((ServiceListener) getListener()).serviceChanged(event);
123                                 return null;
124                             }
125                         });
126                     }
127                     else
128                     {
129                         ((ServiceListener) getListener()).serviceChanged(event);
130                     }
131                 }
132             }
133         }
134     }
135 }
Popular Tags