1 /*
2 * Copyright 2014 The Netty Project
3 *
4 * The Netty Project licenses this file to you under the Apache License, version 2.0 (the
5 * "License"); you may not use this file except in compliance with the License. You may obtain a
6 * 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 distributed under the License
11 * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
12 * or implied. See the License for the specific language governing permissions and limitations under
13 * the License.
14 */
15 package io.netty.util.internal;
16
17 /**
18 * A grab-bag of useful utility methods.
19 */
20 public final class ObjectUtil {
21
22 private ObjectUtil() {
23 }
24
25 /**
26 * Checks that the given argument is not null. If it is, throws {@link NullPointerException}.
27 * Otherwise, returns the argument.
28 */
29 public static <T> T checkNotNull(T arg, String text) {
30 if (arg == null) {
31 throw new NullPointerException(text);
32 }
33 return arg;
34 }
35
36 /**
37 * Checks that the given argument is strictly positive. If it is not, throws {@link IllegalArgumentException}.
38 * Otherwise, returns the argument.
39 */
40 public static int checkPositive(int i, String name) {
41 if (i <= 0) {
42 throw new IllegalArgumentException(name + ": " + i + " (expected: > 0)");
43 }
44 return i;
45 }
46
47 /**
48 * Checks that the given argument is strictly positive. If it is not, throws {@link IllegalArgumentException}.
49 * Otherwise, returns the argument.
50 */
51 public static long checkPositive(long i, String name) {
52 if (i <= 0) {
53 throw new IllegalArgumentException(name + ": " + i + " (expected: > 0)");
54 }
55 return i;
56 }
57
58 /**
59 * Checks that the given argument is positive or zero. If it is not , throws {@link IllegalArgumentException}.
60 * Otherwise, returns the argument.
61 */
62 public static int checkPositiveOrZero(int i, String name) {
63 if (i < 0) {
64 throw new IllegalArgumentException(name + ": " + i + " (expected: >= 0)");
65 }
66 return i;
67 }
68
69 /**
70 * Checks that the given argument is positive or zero. If it is not, throws {@link IllegalArgumentException}.
71 * Otherwise, returns the argument.
72 */
73 public static long checkPositiveOrZero(long i, String name) {
74 if (i < 0) {
75 throw new IllegalArgumentException(name + ": " + i + " (expected: >= 0)");
76 }
77 return i;
78 }
79
80 /**
81 * Checks that the given argument is neither null nor empty.
82 * If it is, throws {@link NullPointerException} or {@link IllegalArgumentException}.
83 * Otherwise, returns the argument.
84 */
85 public static <T> T[] checkNonEmpty(T[] array, String name) {
86 checkNotNull(array, name);
87 checkPositive(array.length, name + ".length");
88 return array;
89 }
90
91 /**
92 * Resolves a possibly null Integer to a primitive int, using a default value.
93 * @param wrapper the wrapper
94 * @param defaultValue the default value
95 * @return the primitive value
96 */
97 public static int intValue(Integer wrapper, int defaultValue) {
98 return wrapper != null ? wrapper : defaultValue;
99 }
100
101 /**
102 * Resolves a possibly null Long to a primitive long, using a default value.
103 * @param wrapper the wrapper
104 * @param defaultValue the default value
105 * @return the primitive value
106 */
107 public static long longValue(Long wrapper, long defaultValue) {
108 return wrapper != null ? wrapper : defaultValue;
109 }
110 }