1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * https://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 package org.apache.commons.lang3.mutable;
19
20 import java.util.function.Supplier;
21
22 /**
23 * Provides mutable access to a value.
24 * <p>
25 * {@link Mutable} is used as a generic interface to the implementations in this package.
26 * </p>
27 * <p>
28 * A typical use case would be to enable a primitive or string to be passed to a method and allow that method to effectively change the value of the
29 * primitive/object. Another use case is to store a frequently changing primitive in a collection (for example a total in a map) without needing to create new
30 * Integer/Long wrapper objects.
31 * </p>
32 *
33 * @param <T> the type to wrap.
34 * @since 2.1
35 */
36 public interface Mutable<T> extends Supplier<T> {
37
38 /**
39 * Gets the value of this mutable.
40 *
41 * @return the stored value.
42 * @since 3.18.0
43 */
44 @Override
45 default T get() {
46 return getValue();
47 }
48
49 /**
50 * Gets the value of this mutable.
51 *
52 * @return the stored value
53 * @deprecated Use {@link #get()}.
54 */
55 @Deprecated
56 T getValue();
57
58 /**
59 * Sets the value of this mutable.
60 *
61 * @param value the value to store
62 * @throws NullPointerException if the object is null and null is invalid.
63 * @throws ClassCastException if the type is invalid.
64 */
65 void setValue(T value);
66 }