SerialDevice.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.ucprelayboard.internal;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

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

import gnu.io.CommPortIdentifier;
import gnu.io.NoSuchPortException;
import gnu.io.PortInUseException;
import gnu.io.SerialPort;
import gnu.io.UnsupportedCommOperationException;

/**
 * This class represents a serial device
 *
 * @author Robert Michalak
 * @since 1.8.0
 */

public class SerialDevice {

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

    private SerialDeviceConfig config;

    private CommPortIdentifier portId;
    private SerialPort serialPort;

    private InputStream inputStream;
    private OutputStream outputStream;

    public SerialDevice(SerialDeviceConfig config) {
        this.config = config;
    }

    public SerialDeviceConfig getConfig() {
        return config;
    }

    /**
     * Initialize this device and open the serial port
     * 
     * @throws InitializationException
     *             if port can not be opened
     */
    public void initialize() throws InitializationException {
        try {
            portId = CommPortIdentifier.getPortIdentifier(config.getPort());

            if (portId != null) {
                // initialize serial port
                serialPort = portId.open("openHAB", 2000);

                // set port parameters
                serialPort.setSerialPortParams(config.getBaud(), SerialPort.DATABITS_8, SerialPort.STOPBITS_1,
                        SerialPort.PARITY_NONE);

                inputStream = serialPort.getInputStream();

                outputStream = serialPort.getOutputStream();

            } else {
                throw new InitializationException("Serial port '" + config.getPort() + "' could not be found.\n");
            }
        } catch (UnsupportedCommOperationException e) {
            throw new InitializationException(e);
        } catch (IOException e) {
            throw new InitializationException(e);
        } catch (PortInUseException e) {
            throw new InitializationException(e);
        } catch (NoSuchPortException e) {
            throw new InitializationException(e);
        }
    }

    /**
     * Sends a string to the serial port of this device
     * 
     * @param relayBoardCommand
     *            the string to send
     */
    public void writeBytes(byte[] relayBoardCommand) {
        try {
            // write bytes to serial port
            outputStream.write(relayBoardCommand);
            outputStream.flush();
        } catch (IOException e) {
            logger.error("Error writing to serial port {}: {}", new Object[] { config.getPort(), e.getMessage() });
        }
    }

    public byte[] readBytes(final byte[] buffer) {
        try {
            if (inputStream.available() > 0) {
                inputStream.read(buffer);
            }
        } catch (IOException e) {
            logger.error("Error reading from serial port {}: {}", new Object[] { config.getPort(), e.getMessage() });
        }
        return buffer;
    }

    /**
     * Close this serial device
     */
    public void close() {
        IOUtils.closeQuietly(outputStream);
        IOUtils.closeQuietly(inputStream);
        serialPort.close();
    }

}