org.apache.commons.lang3.mutable.Mutable Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of commons-lang3 Show documentation

Apache Commons Lang, a package of Java utility classes for the classes that are in java.lang's hierarchy, or are considered to be so standard as to justify existence in java.lang. The code is tested using the latest revision of the JDK for supported LTS releases: 8, 11, 17 and 21 currently. See https://github.com/apache/commons-lang/blob/master/.github/workflows/maven.yml Please ensure your build environment is up-to-date and kindly report any build issues.

There is a newer version: 3.17.0

Show newest version

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.commons.lang3.mutable;

/**
 * Provides mutable access to a value.
 * 
 * Mutable is used as a generic interface to the implementations in this package.
 * 
 * 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 primitive/string. 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 Integer/Long wrapper objects.
 *
 * @param  the type to set and get
 * @since 2.1
 */
public interface Mutable {

    /**
     * Gets the value of this mutable.
     *
     * @return the stored value
     */
    T getValue();

    /**
     * Sets the value of this mutable.
     *
     * @param value
     *            the value to store
     * @throws NullPointerException
     *             if the object is null and null is invalid
     * @throws ClassCastException
     *             if the type is invalid
     */
    void setValue(T value);

}