/***
* Copyright 2002-2010 jamod development team
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
***/
package net.wimpi.modbus.net;
import net.wimpi.modbus.Modbus;
import net.wimpi.modbus.io.ModbusUDPTransport;
import net.wimpi.modbus.util.LinkedQueue;
import net.wimpi.modbus.util.ModbusUtil;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.util.Hashtable;
/**
* Class implementing a <tt>UDPSlaveTerminal</tt>.
*
* @author Dieter Wimberger
* @version @version@ (@date@)
*/
class UDPSlaveTerminal
implements UDPTerminal {
//instance attributes
private DatagramSocket m_Socket;
private int m_Timeout = Modbus.DEFAULT_TIMEOUT;
private boolean m_Active;
protected InetAddress m_LocalAddress;
private int m_LocalPort = Modbus.DEFAULT_PORT;
protected ModbusUDPTransport m_ModbusTransport;
private int m_Retries = Modbus.DEFAULT_RETRIES;
private LinkedQueue m_SendQueue;
private LinkedQueue m_ReceiveQueue;
private PacketSender m_PacketSender;
private PacketReceiver m_PacketReceiver;
private Thread m_Receiver;
private Thread m_Sender;
protected Hashtable m_Requests;
protected UDPSlaveTerminal() {
m_SendQueue = new LinkedQueue();
m_ReceiveQueue = new LinkedQueue();
//m_Requests = new Hashtable(342,0.75F);
m_Requests = new Hashtable(342);
}//constructor
protected UDPSlaveTerminal(InetAddress localaddress) {
m_LocalAddress = localaddress;
m_SendQueue = new LinkedQueue();
m_ReceiveQueue = new LinkedQueue();
//m_Requests = new Hashtable(342, 0.75F);
m_Requests = new Hashtable(342);
}//constructor
public InetAddress getLocalAddress() {
return m_LocalAddress;
}//getLocalAddress
public int getLocalPort() {
return m_LocalPort;
}//getLocalPort
protected void setLocalPort(int port) {
m_LocalPort = port;
}//setLocalPort
/**
* Tests if this <tt>UDPSlaveTerminal</tt> is active.
*
* @return <tt>true</tt> if active, <tt>false</tt> otherwise.
*/
public boolean isActive() {
return m_Active;
}//isActive
/**
* Activate this <tt>UDPTerminal</tt>.
*
* @throws Exception if there is a network failure.
*/
public synchronized void activate()
throws Exception {
if (!isActive()) {
if (Modbus.debug) System.out.println("UDPSlaveTerminal::activate()");
if (m_Socket == null) {
if (m_LocalAddress != null && m_LocalPort != -1) {
m_Socket = new DatagramSocket(m_LocalPort, m_LocalAddress);
} else {
m_Socket = new DatagramSocket();
m_LocalPort = m_Socket.getLocalPort();
m_LocalAddress = m_Socket.getLocalAddress();
}
}
if (Modbus.debug) System.out.println("UDPSlaveTerminal::haveSocket():" + m_Socket.toString());
if (Modbus.debug) System.out.println("UDPSlaveTerminal::addr=:" + m_LocalAddress.toString() + ":port=" + m_LocalPort);
m_Socket.setReceiveBufferSize(1024);
m_Socket.setSendBufferSize(1024);
m_PacketReceiver = new PacketReceiver();
m_Receiver = new Thread(m_PacketReceiver);
m_Receiver.start();
if (Modbus.debug) System.out.println("UDPSlaveTerminal::receiver started()");
m_PacketSender = new PacketSender();
m_Sender = new Thread(m_PacketSender);
m_Sender.start();
if (Modbus.debug) System.out.println("UDPSlaveTerminal::sender started()");
m_ModbusTransport = new ModbusUDPTransport(this);
if (Modbus.debug) System.out.println("UDPSlaveTerminal::transport created");
m_Active = true;
}
if (Modbus.debug) System.out.println("UDPSlaveTerminal::activated");
}//activate
/**
* Deactivates this <tt>UDPSlaveTerminal</tt>.
*/
public void deactivate() {
try {
if (m_Active) {
//1. stop receiver
m_PacketReceiver.stop();
m_Receiver.join();
//2. stop sender gracefully
m_PacketSender.stop();
m_Sender.join();
//3. close socket
m_Socket.close();
m_ModbusTransport = null;
m_Active = false;
}
} catch (Exception ex) {
ex.printStackTrace();
}
}//deactivate
/**
* Returns the <tt>ModbusTransport</tt> associated with this
* <tt>TCPMasterConnection</tt>.
*
* @return the connection's <tt>ModbusTransport</tt>.
*/
public ModbusUDPTransport getModbusTransport() {
return m_ModbusTransport;
}//getModbusTransport
protected boolean hasResponse() {
return !m_ReceiveQueue.isEmpty();
}//hasResponse
/**
* Returns the timeout for this <tt>UDPSlaveTerminal</tt>.
*
* @return the timeout as <tt>int</tt>.
*
public int getReceiveTimeout() {
return m_Timeout;
}//getReceiveTimeout
/**
* Sets the timeout for this <tt>UDPSlaveTerminal</tt>.
*
* @param timeout the timeout as <tt>int</tt>.
*
public void setReceiveTimeout(int timeout) {
m_Timeout = timeout;
try {
m_Socket.setSoTimeout(m_Timeout);
} catch (IOException ex) {
ex.printStackTrace();
//handle?
}
}//setReceiveTimeout
*/
/**
* Returns the socket of this <tt>UDPSlaveTerminal</tt>.
*
* @return the socket as <tt>DatagramSocket</tt>.
*/
public DatagramSocket getSocket() {
return m_Socket;
}//getSocket
/**
* Sets the socket of this <tt>UDPTerminal</tt>.
*
* @param sock the <tt>DatagramSocket</tt> for this terminal.
*/
protected void setSocket(DatagramSocket sock) {
m_Socket = sock;
}//setSocket
public void sendMessage(byte[] msg)
throws Exception {
m_SendQueue.put(msg);
}//sendPackage
public byte[] receiveMessage()
throws Exception {
return (byte[]) m_ReceiveQueue.take();
}//receiveMessage
class PacketSender
implements Runnable {
private boolean m_Continue;
public PacketSender() {
m_Continue = true;
}//constructor
public void run() {
do {
try {
//1. pickup the message and corresponding request
byte[] message = (byte[]) m_SendQueue.take();
DatagramPacket req = (DatagramPacket)
m_Requests.remove(new Integer(ModbusUtil.registersToInt(message)));
//2. create new Package with corresponding address and port
DatagramPacket res = new DatagramPacket(message,
message.length,
req.getAddress(),
req.getPort());
m_Socket.send(res);
if (Modbus.debug) System.out.println("Sent package from queue.");
} catch (Exception ex) {
DEBUG:ex.printStackTrace();
}
} while (m_Continue || !m_SendQueue.isEmpty());
}//run
public void stop() {
m_Continue = false;
}//stop
}//PacketSender
class PacketReceiver
implements Runnable {
private boolean m_Continue;
public PacketReceiver() {
m_Continue = true;
}//constructor
public void run() {
do {
try {
//1. Prepare buffer and receive package
byte[] buffer = new byte[256];//max size
DatagramPacket packet = new DatagramPacket(buffer, buffer.length);
m_Socket.receive(packet);
//2. Extract TID and remember request
Integer tid = new Integer(ModbusUtil.registersToInt(buffer));
m_Requests.put(tid, packet);
//3. place the data buffer in the queue
m_ReceiveQueue.put(buffer);
if (Modbus.debug) System.out.println("Received package to queue.");
} catch (Exception ex) {
DEBUG:ex.printStackTrace();
}
} while (m_Continue);
}//run
public void stop() {
m_Continue = false;
}//stop
}//PacketReceiver
}//class UDPTerminal