01: /*
02: * Copyright 1999 Sun Microsystems, Inc. All Rights Reserved.
03: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
04: *
05: * This code is free software; you can redistribute it and/or modify it
06: * under the terms of the GNU General Public License version 2 only, as
07: * published by the Free Software Foundation. Sun designates this
08: * particular file as subject to the "Classpath" exception as provided
09: * by Sun in the LICENSE file that accompanied this code.
10: *
11: * This code is distributed in the hope that it will be useful, but WITHOUT
12: * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13: * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14: * version 2 for more details (a copy is included in the LICENSE file that
15: * accompanied this code).
16: *
17: * You should have received a copy of the GNU General Public License version
18: * 2 along with this work; if not, write to the Free Software Foundation,
19: * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20: *
21: * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
22: * CA 95054 USA or visit www.sun.com if you need additional information or
23: * have any questions.
24: */
25:
26: package sun.awt;
27:
28: /**
29: * The AWTSecurityManager class provides the ability to secondarily
30: * index AppContext objects through SecurityManager extensions.
31: * As noted in AppContext.java, AppContexts are primarily indexed by
32: * ThreadGroup. In the case where the ThreadGroup doesn't provide
33: * enough information to determine AppContext (e.g. system threads),
34: * if a SecurityManager is installed which derives from
35: * AWTSecurityManager, the AWTSecurityManager's getAppContext()
36: * method is called to determine the AppContext.
37: *
38: * A typical example of the use of this class is where an applet
39: * is called by a system thread, yet the system AppContext is
40: * inappropriate, because applet code is currently executing.
41: * In this case, the getAppContext() method can walk the call stack
42: * to determine the applet code being executed and return the applet's
43: * AppContext object.
44: *
45: * @author Fred Ecks
46: * @version 1.14 05/05/07
47: */
48: public class AWTSecurityManager extends SecurityManager {
49:
50: /**
51: * Get the AppContext corresponding to the current context.
52: * The default implementation returns null, but this method
53: * may be overridden by various SecurityManagers
54: * (e.g. AppletSecurity) to index AppContext objects by the
55: * calling context.
56: *
57: * @return the AppContext corresponding to the current context.
58: * @see sun.awt.AppContext
59: * @see java.lang.SecurityManager
60: * @since JDK1.2.1
61: */
62: public AppContext getAppContext() {
63: return null; // Default implementation returns null
64: }
65:
66: } /* class AWTSecurityManager */
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