/*
* 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.sshd.common.io;
import java.util.Iterator;
import java.util.ServiceLoader;
import java.util.concurrent.ExecutorService;
import org.apache.sshd.common.FactoryManager;
import org.apache.sshd.common.util.GenericUtils;
import org.apache.sshd.common.util.threads.ExecutorServiceConfigurer;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* @author <a href="mailto:dev@mina.apache.org">Apache MINA SSHD Project</a>
*/
public class DefaultIoServiceFactoryFactory extends AbstractIoServiceFactoryFactory {
private static final Logger LOGGER = LoggerFactory.getLogger(DefaultIoServiceFactoryFactory.class);
private IoServiceFactoryFactory factory;
public DefaultIoServiceFactoryFactory() {
this(null, true);
}
protected DefaultIoServiceFactoryFactory(ExecutorService executors, boolean shutdownOnExit) {
super(executors, shutdownOnExit);
}
@Override
public IoServiceFactory create(FactoryManager manager) {
return getFactory().create(manager);
}
private IoServiceFactoryFactory getFactory() {
synchronized (this) {
if (factory == null) {
factory = newInstance(IoServiceFactoryFactory.class);
if (factory instanceof ExecutorServiceConfigurer) {
ExecutorServiceConfigurer configurer = (ExecutorServiceConfigurer) factory;
configurer.setExecutorService(getExecutorService());
configurer.setShutdownOnExit(isShutdownOnExit());
}
}
}
return factory;
}
public static <T extends IoServiceFactoryFactory> T newInstance(Class<T> clazz) {
String factory = System.getProperty(clazz.getName());
if (!GenericUtils.isEmpty(factory)) {
return newInstance(clazz, factory);
}
ClassLoader cl = Thread.currentThread().getContextClassLoader();
if (cl != null) {
T t = tryLoad(ServiceLoader.load(clazz, cl));
if (t != null) {
return t;
}
}
if (cl != DefaultIoServiceFactoryFactory.class.getClassLoader()) {
T t = tryLoad(ServiceLoader.load(clazz, DefaultIoServiceFactoryFactory.class.getClassLoader()));
if (t != null) {
return t;
}
}
throw new IllegalStateException("Could not find a valid sshd io provider");
}
public static <T extends IoServiceFactoryFactory> T tryLoad(ServiceLoader<T> loader) {
Iterator<T> it = loader.iterator();
try {
while (it.hasNext()) {
try {
return it.next();
} catch (Throwable t) {
LOGGER.trace("Exception while loading factory from ServiceLoader", t);
}
}
} catch (Throwable t) {
LOGGER.trace("Exception while loading factory from ServiceLoader", t);
}
return null;
}
public static <T extends IoServiceFactoryFactory> T newInstance(Class<T> clazz, String factory) {
BuiltinIoServiceFactoryFactories builtin = BuiltinIoServiceFactoryFactories.fromFactoryName(factory);
if (builtin != null) {
return clazz.cast(builtin.create());
}
ClassLoader cl = Thread.currentThread().getContextClassLoader();
if (cl != null) {
try {
return clazz.cast(cl.loadClass(factory).newInstance());
} catch (Throwable t) {
LOGGER.trace("Exception while loading factory " + factory, t);
}
}
if (cl != DefaultIoServiceFactoryFactory.class.getClassLoader()) {
try {
return clazz.cast(DefaultIoServiceFactoryFactory.class.getClassLoader().loadClass(factory).newInstance());
} catch (Throwable t) {
LOGGER.trace("Exception while loading factory " + factory, t);
}
}
throw new IllegalStateException("Unable to create instance of class " + factory);
}
}