1 /*
2 * ====================================================================
3 * Licensed to the Apache Software Foundation (ASF) under one
4 * or more contributor license agreements. See the NOTICE file
5 * distributed with this work for additional information
6 * regarding copyright ownership. The ASF licenses this file
7 * to you under the Apache License, Version 2.0 (the
8 * "License"); you may not use this file except in compliance
9 * with the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing,
14 * software distributed under the License is distributed on an
15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16 * KIND, either express or implied. See the License for the
17 * specific language governing permissions and limitations
18 * under the License.
19 * ====================================================================
20 *
21 * This software consists of voluntary contributions made by many
22 * individuals on behalf of the Apache Software Foundation. For more
23 * information on the Apache Software Foundation, please see
24 * <http://www.apache.org/>.
25 *
26 */
27
28 package org.apache.hc.core5.util;
29
30 /**
31 * @since 4.3
32 */
33 public final class TextUtils {
34
35 private TextUtils() {
36 // Do not allow utility class to be instantiated.
37 }
38
39 /**
40 * Returns true if the parameter is null or of zero length
41 */
42 public static boolean isEmpty(final CharSequence s) {
43 return length(s) == 0;
44 }
45
46 /**
47 * <p>Checks if a CharSequence is empty (""), null or whitespace only.</p>
48 *
49 * <p>Whitespace is defined by {@link Character#isWhitespace(char)}.</p>
50 *
51 * <pre>
52 * TextUtils.isBlank(null) = true
53 * TextUtils.isBlank("") = true
54 * TextUtils.isBlank(" ") = true
55 * TextUtils.isBlank("abg") = false
56 * TextUtils.isBlank(" abg ") = false
57 * </pre>
58 *
59 * @param s the CharSequence to check, may be null
60 * @return {@code true} if the CharSequence is null, empty or whitespace only
61 */
62 public static boolean isBlank(final CharSequence s) {
63 final int strLen = length(s);
64 if (strLen == 0) {
65 return true;
66 }
67 for (int i = 0; i < strLen; i++) {
68 if (!Character.isWhitespace(s.charAt(i))) {
69 return false;
70 }
71 }
72 return true;
73 }
74
75 /**
76 * Gets a CharSequence length or {@code 0} if the CharSequence is
77 * {@code null}.
78 *
79 * @param cs
80 * a CharSequence or {@code null}
81 * @return CharSequence length or {@code 0} if the CharSequence is
82 * {@code null}.
83 * @since 5.1
84 */
85 public static int length(final CharSequence cs) {
86 return cs == null ? 0 : cs.length();
87 }
88
89 /**
90 * @since 4.4
91 */
92 public static boolean containsBlanks(final CharSequence s) {
93 final int strLen = length(s);
94 if (strLen == 0) {
95 return false;
96 }
97 for (int i = 0; i < s.length(); i++) {
98 if (Character.isWhitespace(s.charAt(i))) {
99 return true;
100 }
101 }
102 return false;
103 }
104
105 /**
106 * Returns a hexadecimal string with lowercase letters, representing the
107 * values of the {@code bytes}.
108 *
109 * @param bytes whose hex string should be created
110 * @return hex string for the bytes
111 *
112 * @since 5.0
113 */
114 public static String toHexString(final byte[] bytes) {
115 if (bytes == null) {
116 return null;
117 }
118 final StringBuilder buffer = new StringBuilder();
119 for (int i = 0; i < bytes.length; i++) {
120 final int unsignedB = bytes[i] & 0xff;
121 if (unsignedB < 16) {
122 buffer.append('0');
123 }
124 buffer.append(Integer.toHexString(unsignedB));
125 }
126 return buffer.toString();
127 }
128
129 }