01: /*
02: * Bytecode Analysis Framework
03: * Copyright (C) 2003,2004 University of Maryland
04: *
05: * This library is free software; you can redistribute it and/or
06: * modify it under the terms of the GNU Lesser General Public
07: * License as published by the Free Software Foundation; either
08: * version 2.1 of the License, or (at your option) any later version.
09: *
10: * This library is distributed in the hope that it will be useful,
11: * but WITHOUT ANY WARRANTY; without even the implied warranty of
12: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13: * Lesser General Public License for more details.
14: *
15: * You should have received a copy of the GNU Lesser General Public
16: * License along with this library; if not, write to the Free Software
17: * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18: */
19:
20: package edu.umd.cs.findbugs.ba;
21:
22: public class ResourceValue {
23: private ResourceValue() {
24: }
25:
26: private static final ResourceValue instance = new ResourceValue();
27: private static final ResourceValue notInstance = new ResourceValue();
28:
29: public static ResourceValue instance() {
30: return instance;
31: }
32:
33: public static ResourceValue notInstance() {
34: return notInstance;
35: }
36:
37: public static ResourceValue merge(ResourceValue a, ResourceValue b) {
38: if (a == notInstance && b == notInstance)
39: return notInstance;
40: else
41: return instance;
42: }
43:
44: public boolean isInstance() {
45: return this == instance;
46: }
47:
48: @Override
49: public String toString() {
50: return (this == instance) ? "I" : "-";
51: }
52: }
53:
54: // vim:ts=4
|