01: /*BEGIN_COPYRIGHT_BLOCK
02: *
03: * Copyright (c) 2001-2007, JavaPLT group at Rice University (javaplt@rice.edu)
04: * All rights reserved.
05: *
06: * Redistribution and use in source and binary forms, with or without
07: * modification, are permitted provided that the following conditions are met:
08: * * Redistributions of source code must retain the above copyright
09: * notice, this list of conditions and the following disclaimer.
10: * * Redistributions in binary form must reproduce the above copyright
11: * notice, this list of conditions and the following disclaimer in the
12: * documentation and/or other materials provided with the distribution.
13: * * Neither the names of DrJava, the JavaPLT group, Rice University, nor the
14: * names of its contributors may be used to endorse or promote products
15: * derived from this software without specific prior written permission.
16: *
17: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
18: * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
19: * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
20: * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
21: * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
22: * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
23: * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
24: * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
25: * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
26: * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
27: * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28: *
29: * This software is Open Source Initiative approved Open Source Software.
30: * Open Source Initative Approved is a trademark of the Open Source Initiative.
31: *
32: * This file is part of DrJava. Download the current version of this project
33: * from http://www.drjava.org/ or http://sourceforge.net/projects/drjava/
34: *
35: * END_COPYRIGHT_BLOCK*/
36:
37: package edu.rice.cs.util;
38:
39: import java.io.File;
40: import java.io.Serializable;
41:
42: /** A null file. This class is NOT a singleton because we need multiple, distinct null files for untitled documents.
43: * The equals method is overridden so that distinct NullFile objects (which all have the same path) are unequal.
44: */
45: public class NullFile extends File implements Serializable {
46:
47: private static volatile int ct = 0;
48:
49: public NullFile() {
50: super ("*NullFile<" + ct + ">");
51: ct++;
52: }
53:
54: /* The following two method hide the fact that the name field of this file has the form "*NullFile<ct>". They can
55: * be commented out for debugging purposes. */
56: public String toString() {
57: return "(Untitled)";
58: }
59:
60: public String getName() {
61: return "(Untitled)";
62: }
63:
64: /** All distinct objects of type NullFile are unequal. */
65: public boolean equals(Object o) {
66: if (o == null || o.getClass() != getClass())
67: return false;
68: return o == this;
69: }
70:
71: }
|