| /* |
| * 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.concurrent; |
| |
| /** |
| * <p> |
| * Definition of an interface for the thread-safe initialization of objects. |
| * </p> |
| * <p> |
| * The idea behind this interface is to provide access to an object in a |
| * thread-safe manner. A {@code ConcurrentInitializer} can be passed to multiple |
| * threads which can all access the object produced by the initializer. Through |
| * the {@link #get()} method the object can be queried. |
| * </p> |
| * <p> |
| * Concrete implementations of this interface will use different strategies for |
| * the creation of the managed object, e.g. lazy initialization or |
| * initialization in a background thread. This is completely transparent to |
| * client code, so it is possible to change the initialization strategy without |
| * affecting clients. |
| * </p> |
| * |
| * @since 3.0 |
| * @param <T> the type of the object managed by this initializer class |
| */ |
| public interface ConcurrentInitializer<T> { |
| /** |
| * Returns the fully initialized object produced by this {@code |
| * ConcurrentInitializer}. A concrete implementation here returns the |
| * results of the initialization process. This method may block until |
| * results are available. Typically, once created the result object is |
| * always the same. |
| * |
| * @return the object created by this {@code ConcurrentException} |
| * @throws ConcurrentException if an error occurred during initialization of |
| * the object |
| */ |
| T get() throws ConcurrentException; |
| } |