1adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project/* 2adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * Licensed to the Apache Software Foundation (ASF) under one or more 3adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * contributor license agreements. See the NOTICE file distributed with 4adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * this work for additional information regarding copyright ownership. 5adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * The ASF licenses this file to You under the Apache License, Version 2.0 6adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * (the "License"); you may not use this file except in compliance with 7adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * the License. You may obtain a copy of the License at 8adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * 9adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * http://www.apache.org/licenses/LICENSE-2.0 10adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * 11adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * Unless required by applicable law or agreed to in writing, software 12adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * distributed under the License is distributed on an "AS IS" BASIS, 13adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * See the License for the specific language governing permissions and 15adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * limitations under the License. 16adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 17adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 18adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Projectpackage java.nio.channels.spi; 19adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 20adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Projectimport java.io.IOException; 21ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughesimport java.nio.SelectorProviderImpl; 22adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Projectimport java.nio.channels.Channel; 23adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Projectimport java.nio.channels.DatagramChannel; 24adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Projectimport java.nio.channels.Pipe; 25adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Projectimport java.nio.channels.ServerSocketChannel; 26adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Projectimport java.nio.channels.SocketChannel; 2764e526d079a7218f984eeaba6ff2feeaadeeaffbElliott Hughesimport java.util.ServiceLoader; 28adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 29adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project/** 30adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * {@code SelectorProvider} is an abstract base class that declares methods for 31adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * providing instances of {@link DatagramChannel}, {@link Pipe}, 32adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * {@link java.nio.channels.Selector} , {@link ServerSocketChannel}, and 33adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * {@link SocketChannel}. All the methods of this class are thread-safe. 3464e526d079a7218f984eeaba6ff2feeaadeeaffbElliott Hughes * 3564e526d079a7218f984eeaba6ff2feeaadeeaffbElliott Hughes * <p>A provider instance can be retrieved through a system property or the 3664e526d079a7218f984eeaba6ff2feeaadeeaffbElliott Hughes * configuration file in a jar file; if no provider is available that way then 37adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * the system default provider is returned. 38adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 3964e526d079a7218f984eeaba6ff2feeaadeeaffbElliott Hughespublic abstract class SelectorProvider { 40ae704b984c10a63883cc366e823d53902d6ac7a9Elliott Hughes 41adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project private static SelectorProvider provider = null; 42eaa2ff09069424b0f7a95c7cd831cef1b744fe67Jesse Wilson 43adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 44adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * Constructs a new {@code SelectorProvider}. 45adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 46adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project protected SelectorProvider() { 47adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 48adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 49adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 50adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * Gets a provider instance by executing the following steps when called for 51adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * the first time: 52adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * <ul> 53adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * <li> if the system property "java.nio.channels.spi.SelectorProvider" is 54adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * set, the value of this property is the class name of the provider 55adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * returned; </li> 56adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * <li>if there is a provider-configuration file named 57adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * "java.nio.channels.spi.SelectorProvider" in META-INF/services of a jar 58adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * file valid in the system class loader, the first class name is the 59adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * provider's class name; </li> 60adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * <li> otherwise, a system default provider will be returned.</li> 61adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * </ul> 62eaa2ff09069424b0f7a95c7cd831cef1b744fe67Jesse Wilson * 63adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @return the provider. 64adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 65adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project synchronized public static SelectorProvider provider() { 6664e526d079a7218f984eeaba6ff2feeaadeeaffbElliott Hughes if (provider == null) { 6764e526d079a7218f984eeaba6ff2feeaadeeaffbElliott Hughes provider = ServiceLoader.loadFromSystemProperty(SelectorProvider.class); 6864e526d079a7218f984eeaba6ff2feeaadeeaffbElliott Hughes if (provider == null) { 69adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project provider = loadProviderByJar(); 70adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 7164e526d079a7218f984eeaba6ff2feeaadeeaffbElliott Hughes if (provider == null) { 72ad41624e761bcf1af9c8008eb45187fc13983717Elliott Hughes provider = new SelectorProviderImpl(); 73adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 74adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 75adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return provider; 76adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 77adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 7864e526d079a7218f984eeaba6ff2feeaadeeaffbElliott Hughes private static SelectorProvider loadProviderByJar() { 79fa65e4a9364363eff71335dfa3520f0c1d788b0dElliott Hughes for (SelectorProvider provider : ServiceLoader.load(SelectorProvider.class)) { 8064e526d079a7218f984eeaba6ff2feeaadeeaffbElliott Hughes return provider; 81adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 82adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project return null; 83adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 84adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 85adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 86adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * Creates a new open {@code DatagramChannel}. 87f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes * 88adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @return the new channel. 89adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @throws IOException 90adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * if an I/O error occurs. 91adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 92adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public abstract DatagramChannel openDatagramChannel() throws IOException; 93adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 94adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 95adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * Creates a new {@code Pipe}. 96f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes * 97adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @return the new pipe. 98adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @throws IOException 99adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * if an I/O error occurs. 100adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 101adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public abstract Pipe openPipe() throws IOException; 102adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 103adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 104adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * Creates a new selector. 105f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes * 106adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @return the new selector. 107adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @throws IOException 108adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * if an I/O error occurs. 109adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 110adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public abstract AbstractSelector openSelector() throws IOException; 111adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 112adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 113adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * Creates a new open {@code ServerSocketChannel}. 114f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes * 115adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @return the new channel. 116adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @throws IOException 117adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * if an I/O error occurs. 118adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 119adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public abstract ServerSocketChannel openServerSocketChannel() 120adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project throws IOException; 121adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 122adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 123adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * Create a new open {@code SocketChannel}. 124f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes * 125adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @return the new channel. 126adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @throws IOException 127adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * if an I/O error occurs. 128adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 129adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public abstract SocketChannel openSocketChannel() throws IOException; 130adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project 131adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project /** 13299e234cc3322b6c88c9d883da45116d9ec8271dbElliott Hughes * Returns the channel inherited from the process that created this VM. 13399e234cc3322b6c88c9d883da45116d9ec8271dbElliott Hughes * On Android, this method always returns null because stdin and stdout are 13499e234cc3322b6c88c9d883da45116d9ec8271dbElliott Hughes * never connected to a socket. 135f33eae7e84eb6d3b0f4e86b59605bb3de73009f3Elliott Hughes * 136adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @return the channel. 137adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * @throws IOException 138adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project * if an I/O error occurs. 139adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project */ 140adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project public Channel inheritedChannel() throws IOException { 141753dcd862b31e85766225590d90ba0b9f481176fElliott Hughes // Android never has stdin/stdout connected to a socket. 142753dcd862b31e85766225590d90ba0b9f481176fElliott Hughes return null; 143adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project } 144adc854b798c1cfe3bfd4c27d68d5cee38ca617daThe Android Open Source Project} 145