01: /*
02: * ====================================================================
03: * JAFFA - Java Application Framework For All
04: *
05: * Copyright (C) 2002 JAFFA Development Group
06: *
07: * This library is free software; you can redistribute it and/or
08: * modify it under the terms of the GNU Lesser General Public
09: * License as published by the Free Software Foundation; either
10: * version 2.1 of the License, or (at your option) any later version.
11: *
12: * This library is distributed in the hope that it will be useful,
13: * but WITHOUT ANY WARRANTY; without even the implied warranty of
14: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15: * Lesser General Public License for more details.
16: *
17: * You should have received a copy of the GNU Lesser General Public
18: * License along with this library; if not, write to the Free Software
19: * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20: *
21: * Redistribution and use of this software and associated documentation ("Software"),
22: * with or without modification, are permitted provided that the following conditions are met:
23: * 1. Redistributions of source code must retain copyright statements and notices.
24: * Redistributions must also contain a copy of this document.
25: * 2. Redistributions in binary form must reproduce the above copyright notice,
26: * this list of conditions and the following disclaimer in the documentation
27: * and/or other materials provided with the distribution.
28: * 3. The name "JAFFA" must not be used to endorse or promote products derived from
29: * this Software without prior written permission. For written permission,
30: * please contact mail to: jaffagroup@yahoo.com.
31: * 4. Products derived from this Software may not be called "JAFFA" nor may "JAFFA"
32: * appear in their names without prior written permission.
33: * 5. Due credit should be given to the JAFFA Project (http://jaffa.sourceforge.net).
34: *
35: * THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESSED OR IMPLIED
36: * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
37: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
38: * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
39: * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
40: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
41: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
42: * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
43: * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
44: * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
45: * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
46: * SUCH DAMAGE.
47: * ====================================================================
48: */
49:
50: /* Generated by Together */
51:
52: package org.jaffa.security;
53:
54: import java.util.ArrayList;
55:
56: /** This is a simple push on, pop off stack implementation for SecurityContext objects
57: */
58: class SecurityContextStack {
59: /** Holds the stack of contexts, the top of the stack is the last entry in the list
60: * @associates SecurityContext
61: */
62: private ArrayList stack = new ArrayList();
63:
64: /** Pushes a SecurityContext on to the top of the stack
65: * @param ctx SecurityContext to push on stack
66: */
67: public void push(SecurityContext ctx) {
68: stack.add(ctx);
69: }
70:
71: /** Pops the SecurityContext that is on the top of the stack off
72: */
73: public void pop() {
74: if (stack.isEmpty())
75: throw new RuntimeException(
76: "Stack UnderFlow, Pop Called On An Empty Stack");
77: else
78: stack.remove(stack.size() - 1);
79: }
80:
81: /** Get the context of the top of the stack
82: * @return Returns the SecurityContext on the top of the stack, or null if the stack is empty
83: */
84: public SecurityContext getContext() {
85: if (stack.isEmpty())
86: return null;
87: else
88: return (SecurityContext) stack.get(stack.size() - 1);
89: }
90: }
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