//License
/***
* Java Modbus Library (jamod)
* Copyright (c) 2002-2004, jamod development team
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the author nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS ``AS
* IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
***/
package net.wimpi.modbus.net;
import java.net.InetAddress;
import net.wimpi.modbus.Modbus;
import net.wimpi.modbus.ModbusCoupler;
import net.wimpi.modbus.ModbusIOException;
import net.wimpi.modbus.io.ModbusUDPTransport;
import net.wimpi.modbus.msg.ModbusRequest;
import net.wimpi.modbus.msg.ModbusResponse;
/**
* Class that implements a ModbusUDPListener.<br>
*
* @author Dieter Wimberger
* @version 1.2rc1 (09/11/2004)
*/
public class ModbusUDPListener {
private UDPSlaveTerminal m_Terminal;
private ModbusUDPHandler m_Handler;
private Thread m_HandlerThread;
private int m_Port = Modbus.DEFAULT_PORT;
private boolean m_Listening;
private InetAddress m_Interface;
/**
* Constructs a new ModbusUDPListener instance.
*/
public ModbusUDPListener() {
}//ModbusUDPListener
/**
* Create a new <tt>ModbusUDPListener</tt> instance
* listening to the given interface address.
*
* @param ifc an <tt>InetAddress</tt> instance.
*/
public ModbusUDPListener(InetAddress ifc) {
m_Interface = ifc;
}//ModbusUDPListener
/**
* Returns the number of the port this <tt>ModbusUDPListener</tt>
* is listening to.
*
* @return the number of the IP port as <tt>int</tt>.
*/
public int getPort() {
return m_Port;
}//getPort
/**
* Sets the number of the port this <tt>ModbusUDPListener</tt>
* is listening to.
*
* @param port the number of the IP port as <tt>int</tt>.
*/
public void setPort(int port) {
m_Port = ((port>0)? port : Modbus.DEFAULT_PORT);
}//setPort
/**
* Starts this <tt>ModbusUDPListener</tt>.
*/
public void start() {
//start listening
try {
if(m_Interface == null) {
m_Terminal = new UDPSlaveTerminal(InetAddress.getLocalHost());
} else {
m_Terminal = new UDPSlaveTerminal(m_Interface);
}
m_Terminal.setLocalPort(m_Port);
m_Terminal.activate();
m_Handler = new ModbusUDPHandler(m_Terminal.getModbusTransport());
m_HandlerThread = new Thread(m_Handler);
m_HandlerThread.start();
} catch (Exception e) {
//FIXME: this is a major failure, how do we handle this
}
m_Listening = true;
}//start
/**
* Stops this <tt>ModbusUDPListener</tt>.
*/
public void stop() {
//stop listening
m_Terminal.deactivate();
m_Handler.stop();
m_Listening = false;
}//stop
/**
* Tests if this <tt>ModbusTCPListener</tt> is listening
* and accepting incoming connections.
*
* @return true if listening (and accepting incoming connections),
* false otherwise.
*/
public boolean isListening() {
return m_Listening;
}//isListening
class ModbusUDPHandler
implements Runnable {
private ModbusUDPTransport m_Transport;
private boolean m_Continue = true;
public ModbusUDPHandler(ModbusUDPTransport transport) {
m_Transport = transport;
}//constructor
public void run() {
try {
do {
//1. read the request
ModbusRequest request = m_Transport.readRequest();
//System.out.println("Request:" + request.getHexMessage());
ModbusResponse response = null;
//test if Process image exists
if (ModbusCoupler.getReference().getProcessImage() == null) {
response =
request.createExceptionResponse(Modbus.ILLEGAL_FUNCTION_EXCEPTION);
} else {
response = request.createResponse();
}
/*DEBUG*/
if (Modbus.debug) System.out.println("Request:" + request.getHexMessage());
if (Modbus.debug) System.out.println("Response:" + response.getHexMessage());
//System.out.println("Response:" + response.getHexMessage());
m_Transport.writeMessage(response);
} while (m_Continue);
} catch (ModbusIOException ex) {
if (!ex.isEOF()) {
//other troubles, output for debug
ex.printStackTrace();
}
} finally {
try {
m_Terminal.deactivate();
} catch (Exception ex) {
//ignore
}
}
}//run
public void stop() {
m_Continue = false;
}//stop
}//inner class ModbusUDPHandler
}//class ModbusUDPListener