Java tutorial
/* * Copyright 2015 Lithium Technologies, Inc. * * Licensed 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 com.lithium.flow.shell.sshj; import static com.google.common.base.Preconditions.checkNotNull; import com.lithium.flow.access.Access; import com.lithium.flow.access.Login; import com.lithium.flow.config.Config; import com.lithium.flow.shell.Shell; import com.lithium.flow.shell.Shore; import com.lithium.flow.shell.util.DecoratedShell; import com.lithium.flow.util.Caches; import java.io.IOException; import java.util.Set; import java.util.concurrent.locks.Lock; import java.util.concurrent.locks.ReentrantLock; import javax.annotation.Nonnull; import org.apache.commons.io.IOUtils; import com.google.common.cache.LoadingCache; import com.google.common.collect.Sets; /** * @author Matt Ayres */ public class SshjShore implements Shore { private final Config config; private final Access access; private final Set<Shell> shells = Sets.newCopyOnWriteArraySet(); private final LoadingCache<String, Lock> locks = Caches.build(key -> new ReentrantLock()); public SshjShore(@Nonnull Config config, @Nonnull Access access) { this.config = checkNotNull(config); this.access = checkNotNull(access); } @Override @Nonnull public Shell getShell(@Nonnull String host) throws IOException { checkNotNull(host); return getShell(access.getLogin(host)); } @Override @Nonnull public Shell getShell(@Nonnull Login login) throws IOException { checkNotNull(login); Sshj client = new Sshj(config, access.getPrompt()); Lock lock = locks.getUnchecked(login.getHost()); lock.lock(); try { Shell shell = new SshjShell(client, login); shells.add(shell); return new DecoratedShell(shell) { @Override public void close() throws IOException { shells.remove(shell); super.close(); } }; } finally { lock.unlock(); } } @Override public void close() throws IOException { shells.forEach(IOUtils::closeQuietly); } }