EBusTCPConnector.java

/**
 * Copyright (c) 2010-2016 by the respective copyright holders.
 *
 * 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.openhab.binding.ebus.internal.connection;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.ConnectException;
import java.net.Socket;

import org.apache.commons.io.IOUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * This is the TCP/IP implementation of the eBus connector. It only handles
 * TCP/IP specific connection/disconnection. All logic is handled by
 * abstract class AbstractEBusConnector.
 *
 * @author Christian Sowada
 * @since 1.7.0
 */
public class EBusTCPConnector extends AbstractEBusWriteConnector {

    private static final Logger logger = LoggerFactory.getLogger(EBusTCPConnector.class);

    /** The tcp socket */
    private Socket socket;

    /** The tcp hostname */
    private String hostname;

    /** The tcp port */
    private int port;

    /** output stream for eBus communication */
    private OutputStream outputStream;

    /** input stream for eBus communication */
    private InputStream inputStream;

    /**
     * Constructor
     * 
     * @param hostname
     * @param port
     */
    public EBusTCPConnector(String hostname, int port) {
        this.hostname = hostname;
        this.port = port;
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.openhab.binding.ebus.connection.AbstractEBusConnector#connect()
     */
    @Override
    protected boolean connect() throws IOException {

        try {
            socket = new Socket(hostname, port);
            socket.setSoTimeout(20000);
            socket.setKeepAlive(true);

            socket.setTcpNoDelay(true);
            socket.setTrafficClass((byte) 0x10);

            // Useful? We try it
            // socket.setReceiveBufferSize(1);
            socket.setSendBufferSize(1);

            inputStream = socket.getInputStream();
            outputStream = socket.getOutputStream();

            return super.connect();

        } catch (ConnectException e) {
            logger.error(e.toString());

        } catch (Exception e) {
            logger.error(e.toString(), e);

        }

        return false;
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.openhab.binding.ebus.connection.AbstractEBusConnector#disconnect()
     */
    @Override
    protected boolean disconnect() throws IOException {

        if (outputStream != null) {
            outputStream.flush();
        }

        IOUtils.closeQuietly(inputStream);
        IOUtils.closeQuietly(outputStream);

        if (socket != null) {
            socket.close();
            socket = null;
        }
        return true;
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.openhab.binding.ebus.internal.connection.AbstractEBusConnector#readByte()
     */
    @Override
    protected int readByte(boolean lowLatency) throws IOException {
        return inputStream.read();
    }

    /*
     * (non-Javadoc)
     * 
     * @see org.openhab.binding.ebus.internal.connection.AbstractEBusWriteConnector#writeByte(int)
     */
    @Override
    protected void writeByte(int b) throws IOException {
        outputStream.write(b);
        outputStream.flush();
    }

    @Override
    protected boolean isReceiveBufferEmpty() throws IOException {
        return inputStream.available() == 0;
    }

    @Override
    protected boolean isConnected() {
        return inputStream != null;
    }

    @Override
    protected void resetInputBuffer() throws IOException {
        int available = inputStream.available();
        if (available > 0) {
            logger.debug("InputBuffer is not empty before sending: {} bytes waiting !", available);
        }
        inputStream.skip(available);
    }

    @Override
    protected InputStream getInputStream() {
        return inputStream;
    }
}