1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
|
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.lang3;
import org.apache.commons.lang3.stream.Streams;
/**
* Operations on {@link CharSet} instances.
*
* <p>This class handles {@code null} input gracefully.
* An exception will not be thrown for a {@code null} input.
* Each method documents its behavior in more detail.</p>
*
* <p>#ThreadSafe#</p>
* @see CharSet
* @since 1.0
*/
public class CharSetUtils {
/**
* Takes an argument in set-syntax, see evaluateSet,
* and identifies whether any of the characters are present in the specified string.
*
* <pre>
* CharSetUtils.containsAny(null, *) = false
* CharSetUtils.containsAny("", *) = false
* CharSetUtils.containsAny(*, null) = false
* CharSetUtils.containsAny(*, "") = false
* CharSetUtils.containsAny("hello", "k-p") = true
* CharSetUtils.containsAny("hello", "a-d") = false
* </pre>
*
* @see CharSet#getInstance(String...) for set-syntax.
* @param str String to look for characters in, may be null
* @param set String[] set of characters to identify, may be null
* @return whether or not the characters in the set are in the primary string
* @since 3.2
*/
public static boolean containsAny(final String str, final String... set) {
if (StringUtils.isEmpty(str) || deepEmpty(set)) {
return false;
}
final CharSet chars = CharSet.getInstance(set);
for (final char c : str.toCharArray()) {
if (chars.contains(c)) {
return true;
}
}
return false;
}
/**
* Takes an argument in set-syntax, see evaluateSet,
* and returns the number of characters present in the specified string.
*
* <pre>
* CharSetUtils.count(null, *) = 0
* CharSetUtils.count("", *) = 0
* CharSetUtils.count(*, null) = 0
* CharSetUtils.count(*, "") = 0
* CharSetUtils.count("hello", "k-p") = 3
* CharSetUtils.count("hello", "a-e") = 1
* </pre>
*
* @see CharSet#getInstance(String...) for set-syntax.
* @param str String to count characters in, may be null
* @param set String[] set of characters to count, may be null
* @return the character count, zero if null string input
*/
public static int count(final String str, final String... set) {
if (StringUtils.isEmpty(str) || deepEmpty(set)) {
return 0;
}
final CharSet chars = CharSet.getInstance(set);
int count = 0;
for (final char c : str.toCharArray()) {
if (chars.contains(c)) {
count++;
}
}
return count;
}
/**
* Determines whether or not all the Strings in an array are
* empty or not.
*
* @param strings String[] whose elements are being checked for emptiness
* @return whether or not the String is empty
*/
private static boolean deepEmpty(final String[] strings) {
return Streams.of(strings).allMatch(StringUtils::isEmpty);
}
/**
* Takes an argument in set-syntax, see evaluateSet,
* and deletes any of characters present in the specified string.
*
* <pre>
* CharSetUtils.delete(null, *) = null
* CharSetUtils.delete("", *) = ""
* CharSetUtils.delete(*, null) = *
* CharSetUtils.delete(*, "") = *
* CharSetUtils.delete("hello", "hl") = "eo"
* CharSetUtils.delete("hello", "le") = "ho"
* </pre>
*
* @see CharSet#getInstance(String...) for set-syntax.
* @param str String to delete characters from, may be null
* @param set String[] set of characters to delete, may be null
* @return the modified String, {@code null} if null string input
*/
public static String delete(final String str, final String... set) {
if (StringUtils.isEmpty(str) || deepEmpty(set)) {
return str;
}
return modify(str, set, false);
}
/**
* Takes an argument in set-syntax, see evaluateSet,
* and keeps any of characters present in the specified string.
*
* <pre>
* CharSetUtils.keep(null, *) = null
* CharSetUtils.keep("", *) = ""
* CharSetUtils.keep(*, null) = ""
* CharSetUtils.keep(*, "") = ""
* CharSetUtils.keep("hello", "hl") = "hll"
* CharSetUtils.keep("hello", "le") = "ell"
* </pre>
*
* @see CharSet#getInstance(String...) for set-syntax.
* @param str String to keep characters from, may be null
* @param set String[] set of characters to keep, may be null
* @return the modified String, {@code null} if null string input
* @since 2.0
*/
public static String keep(final String str, final String... set) {
if (str == null) {
return null;
}
if (str.isEmpty() || deepEmpty(set)) {
return StringUtils.EMPTY;
}
return modify(str, set, true);
}
/**
* Implementation of delete and keep
*
* @param str String to modify characters within
* @param set String[] set of characters to modify
* @param expect whether to evaluate on match, or non-match
* @return the modified String, not null
*/
private static String modify(final String str, final String[] set, final boolean expect) {
final CharSet chars = CharSet.getInstance(set);
final StringBuilder buffer = new StringBuilder(str.length());
final char[] chrs = str.toCharArray();
for (final char chr : chrs) {
if (chars.contains(chr) == expect) {
buffer.append(chr);
}
}
return buffer.toString();
}
/**
* Squeezes any repetitions of a character that is mentioned in the
* supplied set.
*
* <pre>
* CharSetUtils.squeeze(null, *) = null
* CharSetUtils.squeeze("", *) = ""
* CharSetUtils.squeeze(*, null) = *
* CharSetUtils.squeeze(*, "") = *
* CharSetUtils.squeeze("hello", "k-p") = "helo"
* CharSetUtils.squeeze("hello", "a-e") = "hello"
* </pre>
*
* @see CharSet#getInstance(String...) for set-syntax.
* @param str the string to squeeze, may be null
* @param set the character set to use for manipulation, may be null
* @return the modified String, {@code null} if null string input
*/
public static String squeeze(final String str, final String... set) {
if (StringUtils.isEmpty(str) || deepEmpty(set)) {
return str;
}
final CharSet chars = CharSet.getInstance(set);
final StringBuilder buffer = new StringBuilder(str.length());
final char[] chrs = str.toCharArray();
final int sz = chrs.length;
char lastChar = chrs[0];
char ch;
Character inChars = null;
Character notInChars = null;
buffer.append(lastChar);
for (int i = 1; i < sz; i++) {
ch = chrs[i];
if (ch == lastChar) {
if (inChars != null && ch == inChars) {
continue;
}
if (notInChars == null || ch != notInChars) {
if (chars.contains(ch)) {
inChars = ch;
continue;
}
notInChars = ch;
}
}
buffer.append(ch);
lastChar = ch;
}
return buffer.toString();
}
/**
* CharSetUtils instances should NOT be constructed in standard programming.
* Instead, the class should be used as {@code CharSetUtils.evaluateSet(null);}.
*
* <p>This constructor is public to permit tools that require a JavaBean instance
* to operate.</p>
*/
public CharSetUtils() {
}
}
|
