/*
 * 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.

Type parameters:
  • <T> – the type to set and get
Since:2.1
/** * Provides mutable access to a value. * <p> * <code>Mutable</code> is used as a generic interface to the implementations in this package. * <p> * 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 <T> the type to set and get * @since 2.1 */
public interface Mutable<T> {
Gets the value of this mutable.
Returns:the stored value
/** * Gets the value of this mutable. * * @return the stored value */
T getValue();
Sets the value of this mutable.
Params:
  • value – the value to store
Throws:
/** * 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); }