1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17 package org.apache.commons.validator.util;
18
19 import java.io.Serializable;
20
21 /***
22 * Represents a collection of 64 boolean (on/off) flags. Individual flags
23 * are represented by powers of 2. For example,<br/>
24 * Flag 1 = 1<br/>
25 * Flag 2 = 2<br/>
26 * Flag 3 = 4<br/>
27 * Flag 4 = 8<br/><br/>
28 * or using shift operator to make numbering easier:<br/>
29 * Flag 1 = 1 << 0<br/>
30 * Flag 2 = 1 << 1<br/>
31 * Flag 3 = 1 << 2<br/>
32 * Flag 4 = 1 << 3<br/>
33 *
34 * <p>
35 * There cannot be a flag with a value of 3 because that represents Flag 1
36 * and Flag 2 both being on/true.
37 * </p>
38 *
39 * @version $Revision: 478334 $ $Date: 2006-11-22 21:31:54 +0000 (Wed, 22 Nov 2006) $
40 */
41 public class Flags implements Serializable {
42
43 /***
44 * Represents the current flag state.
45 */
46 private long flags = 0;
47
48 /***
49 * Create a new Flags object.
50 */
51 public Flags() {
52 super();
53 }
54
55 /***
56 * Initialize a new Flags object with the given flags.
57 *
58 * @param flags collection of boolean flags to represent.
59 */
60 public Flags(long flags) {
61 super();
62 this.flags = flags;
63 }
64
65 /***
66 * Returns the current flags.
67 *
68 * @return collection of boolean flags represented.
69 */
70 public long getFlags() {
71 return this.flags;
72 }
73
74 /***
75 * Tests whether the given flag is on. If the flag is not a power of 2
76 * (ie. 3) this tests whether the combination of flags is on.
77 *
78 * @param flag Flag value to check.
79 *
80 * @return whether the specified flag value is on.
81 */
82 public boolean isOn(long flag) {
83 return (this.flags & flag) > 0;
84 }
85
86 /***
87 * Tests whether the given flag is off. If the flag is not a power of 2
88 * (ie. 3) this tests whether the combination of flags is off.
89 *
90 * @param flag Flag value to check.
91 *
92 * @return whether the specified flag value is off.
93 */
94 public boolean isOff(long flag) {
95 return (this.flags & flag) == 0;
96 }
97
98 /***
99 * Turns on the given flag. If the flag is not a power of 2 (ie. 3) this
100 * turns on multiple flags.
101 *
102 * @param flag Flag value to turn on.
103 */
104 public void turnOn(long flag) {
105 this.flags |= flag;
106 }
107
108 /***
109 * Turns off the given flag. If the flag is not a power of 2 (ie. 3) this
110 * turns off multiple flags.
111 *
112 * @param flag Flag value to turn off.
113 */
114 public void turnOff(long flag) {
115 this.flags &= ~flag;
116 }
117
118 /***
119 * Turn off all flags.
120 */
121 public void turnOffAll() {
122 this.flags = 0;
123 }
124
125 /***
126 * Turn off all flags. This is a synonym for <code>turnOffAll()</code>.
127 * @since Validator 1.1.1
128 */
129 public void clear() {
130 this.flags = 0;
131 }
132
133 /***
134 * Turn on all 64 flags.
135 */
136 public void turnOnAll() {
137 this.flags = Long.MAX_VALUE;
138 }
139
140 /***
141 * Clone this Flags object.
142 *
143 * @return a copy of this object.
144 * @see java.lang.Object#clone()
145 */
146 public Object clone() {
147 try {
148 return super.clone();
149 } catch(CloneNotSupportedException e) {
150 throw new RuntimeException("Couldn't clone Flags object.");
151 }
152 }
153
154 /***
155 * Tests if two Flags objects are in the same state.
156 * @param obj object being tested
157 * @see java.lang.Object#equals(java.lang.Object)
158 *
159 * @return whether the objects are equal.
160 */
161 public boolean equals(Object obj) {
162 if (!(obj instanceof Flags)) {
163 return false;
164 }
165
166 if (obj == this) {
167 return true;
168 }
169
170 Flags f = (Flags) obj;
171
172 return this.flags == f.flags;
173 }
174
175 /***
176 * The hash code is based on the current state of the flags.
177 * @see java.lang.Object#hashCode()
178 *
179 * @return the hash code for this object.
180 */
181 public int hashCode() {
182 return (int) this.flags;
183 }
184
185 /***
186 * Returns a 64 length String with the first flag on the right and the
187 * 64th flag on the left. A 1 indicates the flag is on, a 0 means it's
188 * off.
189 *
190 * @return string representation of this object.
191 */
192 public String toString() {
193 StringBuffer bin = new StringBuffer(Long.toBinaryString(this.flags));
194 for (int i = 64 - bin.length(); i > 0; i--) {
195 bin.insert(0, "0");
196 }
197 return bin.toString();
198 }
199
200 }