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 if (s == null) {
44 return true;
45 }
46 return s.length() == 0;
47 }
48
49 /**
50 * Returns true if the parameter is null or contains only whitespace
51 */
52 public static boolean isBlank(final CharSequence s) {
53 if (s == null) {
54 return true;
55 }
56 for (int i = 0; i < s.length(); i++) {
57 if (!Character.isWhitespace(s.charAt(i))) {
58 return false;
59 }
60 }
61 return true;
62 }
63
64 /**
65 * @since 4.4
66 */
67 public static boolean containsBlanks(final CharSequence s) {
68 if (s == null) {
69 return false;
70 }
71 for (int i = 0; i < s.length(); i++) {
72 if (Character.isWhitespace(s.charAt(i))) {
73 return true;
74 }
75 }
76 return false;
77 }
78
79 /**
80 * Returns a hexadecimal string with lowercase letters, representing the
81 * values of the {@code bytes}.
82 *
83 * @param bytes whose hex string should be created
84 * @return hex string for the bytes
85 *
86 * @since 5.0
87 */
88 public static String toHexString(final byte[] bytes) {
89 if (bytes == null) {
90 return null;
91 }
92 final StringBuffer buffer = new StringBuffer();
93 for (int i = 0; i < bytes.length; i++) {
94 final int unsignedB = bytes[i] & 0xff;
95 if (unsignedB < 16) {
96 buffer.append('0');
97 }
98 buffer.append(Integer.toHexString(unsignedB));
99 }
100 return buffer.toString();
101 }
102
103 }