/* * This project is licensed under the MIT license. Module model-view-viewmodel is using ZK framework licensed under LGPL (see lgpl-3.0.txt). * * The MIT License * Copyright © 2014-2022 Ilkka Seppälä * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in * all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN * THE SOFTWARE. */ package com.iluwatar.object.pool; import lombok.extern.slf4j.Slf4j; /** * When it is necessary to work with a large number of objects that are particularly expensive to * instantiate and each object is only needed for a short period of time, the performance of an * entire application may be adversely affected. An object pool design pattern may be deemed * desirable in cases such as these. * *
The object pool design pattern creates a set of objects that may be reused. When a new object * is needed, it is requested from the pool. If a previously prepared object is available it is * returned immediately, avoiding the instantiation cost. If no objects are present in the pool, a * new item is created and returned. When the object has been used and is no longer needed, it is * returned to the pool, allowing it to be used again in the future without repeating the * computationally expensive instantiation process. It is important to note that once an object has * been used and returned, existing references will become invalid. * *
In this example we have created {@link OliphauntPool} inheriting from generic {@link * ObjectPool}. {@link Oliphaunt}s can be checked out from the pool and later returned to it. The * pool tracks created instances and their status (available, inUse). */ @Slf4j public class App { /** * Program entry point. * * @param args command line args */ public static void main(String[] args) { var pool = new OliphauntPool(); LOGGER.info(pool.toString()); var oliphaunt1 = pool.checkOut(); String checkedOut = "Checked out {}"; LOGGER.info(checkedOut, oliphaunt1); LOGGER.info(pool.toString()); var oliphaunt2 = pool.checkOut(); LOGGER.info(checkedOut, oliphaunt2); var oliphaunt3 = pool.checkOut(); LOGGER.info(checkedOut, oliphaunt3); LOGGER.info(pool.toString()); LOGGER.info("Checking in {}", oliphaunt1); pool.checkIn(oliphaunt1); LOGGER.info("Checking in {}", oliphaunt2); pool.checkIn(oliphaunt2); LOGGER.info(pool.toString()); var oliphaunt4 = pool.checkOut(); LOGGER.info(checkedOut, oliphaunt4); var oliphaunt5 = pool.checkOut(); LOGGER.info(checkedOut, oliphaunt5); LOGGER.info(pool.toString()); } }