Logback: the reliable, generic, fast and flexible logging framework.
Copyright (C) 1999-2015, QOS.ch. All rights reserved.
This program and the accompanying materials are dual-licensed under
either the terms of the Eclipse Public License v1.0 as published by
the Eclipse Foundation
  or (per the licensee's choosing)
under the terms of the GNU Lesser General Public License version 2.1
as published by the Free Software Foundation.
/**
 * Logback: the reliable, generic, fast and flexible logging framework.
 * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
 *
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation
 *
 *   or (per the licensee's choosing)
 *
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation.
 */
package ch.qos.logback.classic.net;

import java.io.EOFException;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.net.ConnectException;
import java.net.InetAddress;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import java.util.concurrent.RejectedExecutionException;

import javax.net.SocketFactory;

import ch.qos.logback.classic.Logger;
import ch.qos.logback.classic.LoggerContext;
import ch.qos.logback.classic.net.server.HardenedLoggingEventInputStream;
import ch.qos.logback.classic.spi.ILoggingEvent;
import ch.qos.logback.core.net.DefaultSocketConnector;
import ch.qos.logback.core.net.AbstractSocketAppender;
import ch.qos.logback.core.net.SocketConnector;
import ch.qos.logback.core.util.CloseUtil;

A component that receives serialized ILoggingEvent objects from a remote appender over a Socket. 
Author:
Carl Harris/**
 * A component that receives serialized {@link ILoggingEvent} objects from a
 * remote appender over a {@link Socket}.
 *
 * @author Carl Harris
 */
public class SocketReceiver extends ReceiverBase implements Runnable, SocketConnector.ExceptionHandler {

    private static final int DEFAULT_ACCEPT_CONNECTION_DELAY = 5000;

    private String remoteHost;
    private InetAddress address;
    private int port;
    private int reconnectionDelay;
    private int acceptConnectionTimeout = DEFAULT_ACCEPT_CONNECTION_DELAY;

    private String receiverId;
    private volatile Socket socket;
    private Future<Socket> connectorTask;

    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    protected boolean shouldStart() {
        int errorCount = 0;
        if (port == 0) {
            errorCount++;
            addError("No port was configured for receiver. " + "For more information, please visit http://logback.qos.ch/codes.html#receiver_no_port");
        }

        if (remoteHost == null) {
            errorCount++;
            addError("No host name or address was configured for receiver. "
                            + "For more information, please visit http://logback.qos.ch/codes.html#receiver_no_host");
        }

        if (reconnectionDelay == 0) {
            reconnectionDelay = AbstractSocketAppender.DEFAULT_RECONNECTION_DELAY;
        }

        if (errorCount == 0) {
            try {
                address = InetAddress.getByName(remoteHost);
            } catch (UnknownHostException ex) {
                addError("unknown host: " + remoteHost);
                errorCount++;
            }
        }

        if (errorCount == 0) {
            receiverId = "receiver " + remoteHost + ":" + port + ": ";
        }

        return errorCount == 0;
    }

    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    protected void onStop() {
        if (socket != null) {
            CloseUtil.closeQuietly(socket);
        }
    }

    @Override
    protected Runnable getRunnableTask() {
        return this;
    }

    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    public void run() {
        try {
            LoggerContext lc = (LoggerContext) getContext();
            while (!Thread.currentThread().isInterrupted()) {
                SocketConnector connector = createConnector(address, port, 0, reconnectionDelay);
                connectorTask = activateConnector(connector);
                if (connectorTask == null) {
                    break;
                }
                socket = waitForConnectorToReturnASocket();
                if (socket == null)
                    break;
                dispatchEvents(lc);
            }
        } catch (InterruptedException ex) {
            assert true; // ok... we'll exit now
        }
        addInfo("shutting down");
    }

    private SocketConnector createConnector(InetAddress address, int port, int initialDelay, int retryDelay) {
        SocketConnector connector = newConnector(address, port, initialDelay, retryDelay);
        connector.setExceptionHandler(this);
        connector.setSocketFactory(getSocketFactory());
        return connector;
    }

    private Future<Socket> activateConnector(SocketConnector connector) {
        try {
            return getContext().getScheduledExecutorService().submit(connector);
        } catch (RejectedExecutionException ex) {
            return null;
        }
    }

    private Socket waitForConnectorToReturnASocket() throws InterruptedException {
        try {
            Socket s = connectorTask.get();
            connectorTask = null;
            return s;
        } catch (ExecutionException e) {
            return null;
        }
    }

    private void dispatchEvents(LoggerContext lc) {
        ObjectInputStream ois = null;
        try {
            socket.setSoTimeout(acceptConnectionTimeout);
            ois = new HardenedLoggingEventInputStream(socket.getInputStream());
            socket.setSoTimeout(0);
            addInfo(receiverId + "connection established");
            while (true) {
                ILoggingEvent event = (ILoggingEvent) ois.readObject();
                Logger remoteLogger = lc.getLogger(event.getLoggerName());
                if (remoteLogger.isEnabledFor(event.getLevel())) {
                    remoteLogger.callAppenders(event);
                }
            }
        } catch (EOFException ex) {
            addInfo(receiverId + "end-of-stream detected");
        } catch (IOException ex) {
            addInfo(receiverId + "connection failed: " + ex);
        } catch (ClassNotFoundException ex) {
            addInfo(receiverId + "unknown event class: " + ex);
        } finally {
            CloseUtil.closeQuietly(ois);
            CloseUtil.closeQuietly(socket);
            socket = null;
            addInfo(receiverId + "connection closed");
        }
    }

    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    public void connectionFailed(SocketConnector connector, Exception ex) {
        if (ex instanceof InterruptedException) {
            addInfo("connector interrupted");
        } else if (ex instanceof ConnectException) {
            addInfo(receiverId + "connection refused");
        } else {
            addInfo(receiverId + ex);
        }
    }

    protected SocketConnector newConnector(InetAddress address, int port, int initialDelay, int retryDelay) {
        return new DefaultSocketConnector(address, port, initialDelay, retryDelay);
    }

    protected SocketFactory getSocketFactory() {
        return SocketFactory.getDefault();
    }

    public void setRemoteHost(String remoteHost) {
        this.remoteHost = remoteHost;
    }

    public void setPort(int port) {
        this.port = port;
    }

    public void setReconnectionDelay(int reconnectionDelay) {
        this.reconnectionDelay = reconnectionDelay;
    }

    public void setAcceptConnectionTimeout(int acceptConnectionTimeout) {
        this.acceptConnectionTimeout = acceptConnectionTimeout;
    }

}