001package com.pi4j.io.serial; 002 003/* 004 * #%L 005 * ********************************************************************** 006 * ORGANIZATION : Pi4J 007 * PROJECT : Pi4J :: Java Library (Core) 008 * FILENAME : SerialFactory.java 009 * 010 * This file is part of the Pi4J project. More information about 011 * this project can be found here: https://www.pi4j.com/ 012 * ********************************************************************** 013 * %% 014 * Copyright (C) 2012 - 2019 Pi4J 015 * %% 016 * This program is free software: you can redistribute it and/or modify 017 * it under the terms of the GNU Lesser General Public License as 018 * published by the Free Software Foundation, either version 3 of the 019 * License, or (at your option) any later version. 020 * 021 * This program is distributed in the hope that it will be useful, 022 * but WITHOUT ANY WARRANTY; without even the implied warranty of 023 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 024 * GNU General Lesser Public License for more details. 025 * 026 * You should have received a copy of the GNU General Lesser Public 027 * License along with this program. If not, see 028 * <http://www.gnu.org/licenses/lgpl-3.0.html>. 029 * #L% 030 */ 031 032 033import com.pi4j.concurrent.DefaultExecutorServiceFactory; 034import com.pi4j.concurrent.ExecutorServiceFactory; 035import com.pi4j.io.serial.impl.SerialImpl; 036 037/** 038 * <p> This factory class provide a static method to create new 'Serial' instances. </p> 039 * 040 * <p> 041 * Before using the Pi4J library, you need to ensure that the Java VM in configured with access to 042 * the following system libraries: 043 * <ul> 044 * <li>pi4j</li> 045 * <li>wiringPi</li> 046 * </ul> 047 * <blockquote> This library depends on the wiringPi native system library.</br> (developed by 048 * Gordon Henderson @ <a href="http://wiringpi.com/">http://wiringpi.com/</a>) 049 * </blockquote> 050 * </p> 051 * 052 * @see com.pi4j.io.serial.Serial 053 * @see com.pi4j.io.serial.SerialDataEvent 054 * @see SerialDataEventListener 055 * 056 * @see <a href="https://www.pi4j.com/">https://www.pi4j.com/</a> 057 * @author Robert Savage (<a 058 * href="http://www.savagehomeautomation.com">http://www.savagehomeautomation.com</a>) 059 */ 060public class SerialFactory { 061 062 private static boolean isshutdown = false; 063 064 // we only allow a single default scheduled executor service factory to exists 065 private static ExecutorServiceFactory executorServiceFactory = null; 066 067 // private constructor 068 private SerialFactory() { 069 // forbid object construction 070 } 071 072 /** 073 * Create New Serial instance 074 * 075 * @return Return a new Serial implementation instance. 076 */ 077 public static Serial createInstance() { 078 isshutdown = false; 079 return new SerialImpl(); 080 } 081 082 /** 083 * <p>Return instance of {@link ExecutorServiceFactory}.</p> 084 * <p>Note: .</p> 085 * 086 * @return Return a new GpioController impl instance. 087 */ 088 public static ExecutorServiceFactory getExecutorServiceFactory() { 089 // if an executor service provider factory has not been created, then create a new default instance 090 if (executorServiceFactory == null) { 091 executorServiceFactory = new DefaultExecutorServiceFactory(); 092 } 093 // return the provider instance 094 return executorServiceFactory; 095 } 096 097 /** 098 * Sets default {@link ExecutorServiceFactory}. 099 * 100 * @param executorServiceFactory service factory instance 101 */ 102 public static void setExecutorServiceFactory(ExecutorServiceFactory executorServiceFactory) { 103 // set the default factory instance 104 SerialFactory.executorServiceFactory = executorServiceFactory; 105 } 106 107 /** 108 * This method returns TRUE if the serial controller has been shutdown. 109 * 110 * @return shutdown state 111 */ 112 public static boolean isShutdown(){ 113 return isshutdown; 114 } 115 116 117 /** 118 * This method can be called to forcefully shutdown all serial port 119 * monitoring, listening, and task threads/executors. 120 */ 121 public static void shutdown() 122 { 123 // prevent reentrant invocation 124 if(isShutdown()) 125 return; 126 127 // shutdown all executor services 128 // 129 // NOTE: we are not permitted to access the shutdown() method of the individual 130 // executor services, we must perform the shutdown with the factory 131 SerialFactory.getExecutorServiceFactory().shutdown(); 132 133 // set is shutdown tracking variable 134 isshutdown = true; 135 } 136}