| // Copyright 2006, 2007 The Apache Software Foundation |
| // |
| // Licensed 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.tapestry5.internal.util; |
| |
| import java.util.concurrent.atomic.AtomicReference; |
| |
| /** |
| * An object that holds some type of other object. This is useful for communicating information from an inner class |
| * (used as a closure) to the containing method. This is similar to {@link AtomicReference}, except that it is simpler |
| * but <strong>not</strong> thread safe. |
| * |
| * @param <T> |
| */ |
| public class Holder<T> |
| { |
| private T held; |
| |
| public void put(T object) |
| { |
| held = object; |
| } |
| |
| public T get() |
| { |
| return held; |
| } |
| |
| public boolean hasValue() |
| { |
| return held != null; |
| } |
| |
| public static <T> Holder<T> create() |
| { |
| return new Holder<T>(); |
| } |
| } |