Java tutorial
/* * Copyright (c) 2013 Cisco Systems, Inc. and others. All rights reserved. * * This program and the accompanying materials are made available under the * terms of the Eclipse Public License v1.0 which accompanies this distribution, * and is available at http://www.eclipse.org/legal/epl-v10.html */ package org.opendaylight.controller.netconf.nettyutil.handler.ssh.client; import io.netty.buffer.ByteBuf; import io.netty.buffer.Unpooled; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.ChannelPromise; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.util.LinkedList; import java.util.Queue; import java.util.concurrent.atomic.AtomicBoolean; import org.opendaylight.controller.netconf.nettyutil.handler.ssh.virtualsocket.VirtualSocketException; /** * Worker thread class. Handles all downstream and upstream events in SSH Netty * pipeline. */ public class SshClientAdapter implements Runnable { private static final int BUFFER_SIZE = 1024; private final SshClient sshClient; private final Invoker invoker; private OutputStream stdIn; private Queue<ByteBuf> postponed = new LinkedList<>(); private ChannelHandlerContext ctx; private ChannelPromise disconnectPromise; private final AtomicBoolean stopRequested = new AtomicBoolean(false); private final Object lock = new Object(); public SshClientAdapter(SshClient sshClient, Invoker invoker) { this.sshClient = sshClient; this.invoker = invoker; } public void run() { try { SshSession session = sshClient.openSession(); invoker.invoke(session); InputStream stdOut = session.getStdout(); session.getStderr(); synchronized (lock) { stdIn = session.getStdin(); ByteBuf message; while ((message = postponed.poll()) != null) { writeImpl(message); } } while (!stopRequested.get()) { byte[] readBuff = new byte[BUFFER_SIZE]; int c = stdOut.read(readBuff); if (c == -1) { continue; } byte[] tranBuff = new byte[c]; System.arraycopy(readBuff, 0, tranBuff, 0, c); ByteBuf byteBuf = Unpooled.buffer(c); byteBuf.writeBytes(tranBuff); ctx.fireChannelRead(byteBuf); } } catch (VirtualSocketException e) { // Netty closed connection prematurely. // Just pass and move on. } catch (Exception e) { throw new IllegalStateException(e); } finally { sshClient.close(); synchronized (lock) { if (disconnectPromise != null) { ctx.disconnect(disconnectPromise); } } } } // TODO: needs rework to match netconf framer API. public void write(ByteBuf message) throws IOException { synchronized (lock) { if (stdIn == null) { postponed.add(message); return; } writeImpl(message); } } private void writeImpl(ByteBuf message) throws IOException { message.getBytes(0, stdIn, message.readableBytes()); stdIn.flush(); } public void stop(ChannelPromise promise) { synchronized (lock) { stopRequested.set(true); disconnectPromise = promise; } } public void start(ChannelHandlerContext ctx) { if (this.ctx != null) { // context is already associated. return; } this.ctx = ctx; new Thread(this).start(); } }