1 /*
2 * Copyright 2011-2012 smartics, Kronseder & Reiner GmbH
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 package de.smartics.util.lang;
17
18 import org.apache.commons.lang.StringUtils;
19
20 /**
21 * A collection of useful string functions.
22 */
23 public final class StringFunction
24 {
25 // ********************************* Fields *********************************
26
27 // --- constants ------------------------------------------------------------
28
29 // --- members --------------------------------------------------------------
30
31 // ****************************** Initializer *******************************
32
33 // ****************************** Constructors ******************************
34
35 /**
36 * Utility class.
37 */
38 private StringFunction()
39 {
40 }
41
42 // ****************************** Inner Classes *****************************
43
44 // ********************************* Methods ********************************
45
46 // --- init -----------------------------------------------------------------
47
48 // --- get&set --------------------------------------------------------------
49
50 // --- business -------------------------------------------------------------
51
52 /**
53 * Chops off the last character of the buffer and returns the string value of
54 * the modified buffer.
55 * <p>
56 * Removes the last character if the buffer has at least one character.
57 * Returns the value as passed in otherwise.
58 * </p>
59 *
60 * @param buffer the buffer to chop.
61 * @return the content of the buffer except the last character.
62 */
63 public static String chop(final StringBuilder buffer)
64 {
65 if (buffer == null)
66 {
67 return null;
68 }
69 final int length = buffer.length();
70 if (length == 0)
71 {
72 return "";
73 }
74
75 if (length > 1 && buffer.charAt(length - 1) == '\n'
76 && buffer.charAt(length - 2) == '\r')
77 {
78 buffer.setLength(length - 2);
79 }
80 else
81 {
82 buffer.setLength(length - 1);
83 }
84
85 return buffer.toString();
86 }
87
88 /**
89 * Returns the {@code camelCasedString} in a hyphen version.
90 * <p>
91 * Each upper case letter is replaces by a dash and the lower case letter.
92 * </p>
93 *
94 * <pre>
95 * thisIsACamleCaseExample -> this-is-a-camle-case-example
96 * </pre>
97 *
98 * @param camelCasedString the input string.
99 * @return the hyphen version or <code>null</code> if <code>null</code> is
100 * passed as an argument.
101 */
102 public static String toHyphenVersion(final String camelCasedString)
103 {
104 if (StringUtils.isBlank(camelCasedString)
105 || StringUtils.isAllLowerCase(camelCasedString))
106 {
107 return camelCasedString;
108 }
109
110 final int length = camelCasedString.length();
111 final StringBuilder buffer = new StringBuilder(length + 16);
112 for (int i = 0; i < length; i++)
113 {
114 final char c = camelCasedString.charAt(i);
115 if (Character.isUpperCase(c))
116 {
117 if (i != 0)
118 {
119 buffer.append('-');
120 }
121 buffer.append(Character.toLowerCase(c));
122 }
123 else
124 {
125 buffer.append(c);
126 }
127 }
128
129 return buffer.toString();
130 }
131
132 /**
133 * Checks if the last character of the given string matches the given
134 * {@code ch}.
135 *
136 * @param string the string to test.
137 * @param ch the expected last character of {@code string}.
138 * @return <code>true</code> if {@code ch} matches the last character of
139 * {@code string}, <code>false</code> otherwise.
140 */
141 public static boolean isLastChar(final String string, final char ch)
142 {
143 if (StringUtils.isEmpty(string))
144 {
145 return false;
146 }
147
148 final int index = string.length() - 1;
149 final char lastChar = string.charAt(index);
150 return lastChar == ch;
151 }
152
153 /**
154 * Replaces all consecutive white spaces by one space and removes white spaces
155 * from the start and end of the string.
156 *
157 * @param string the string to strip.
158 * @return the stripped string.
159 */
160 public static String strip(final String string)
161 {
162 return string.trim().replaceAll("\\s+", " ");
163 }
164
165 // --- object basics --------------------------------------------------------
166
167 }