Here you can find the source of getExecutorService()
public static ScheduledExecutorService getExecutorService()
//package com.java2s; /**//from w w w . j a v a 2s . co m * MIT License * * Copyright (c) 2017 Vladimir Mikhaylov * * 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. **/ import java.util.concurrent.Executors; import java.util.concurrent.ScheduledExecutorService; public class Main { private static ScheduledExecutorService es = Executors .newScheduledThreadPool(Runtime.getRuntime().availableProcessors() * 2); public static int ADDITIONAL_CORES = 1; private static boolean shutdown; public static ScheduledExecutorService getExecutorService() { if ((es == null || es.isShutdown()) && !isExecutorShutdown()) { es = Executors.newScheduledThreadPool(Runtime.getRuntime().availableProcessors() + ADDITIONAL_CORES); } return es; } public static boolean isExecutorShutdown() { return shutdown; } }