commportserver.java

This package making a GPRS connection using Tini (from Dallas Semiconductors). After connection the

package com.eta.etatcpcomm.server;

import java.io.*;
import java.net.*;
import javax.comm.*;
import com.eta.etatcpcomm.*;

/* This class allows us to perform operations on the CommPort object that this
 * server is talking to.  It also listens for connections on port 10101 (or
 * whatever is specified) and begins a communication session if such a 
 * connection is made.
 */
public abstract class CommPortServer implements Runnable, Constants
{
	protected CommPortServer(CommPortIdentifier commPortIdentifier, int tcpPort)
	{
		this.commPortIdentifier = commPortIdentifier;
		this.tcpPort = tcpPort;
	}

	public abstract int getPortType();

	// Provides access to the underlying CommPort.
	public CommPort getCommPort()
	{
		return cp;
	}

	public synchronized void stop()
	{
		if( state != STOPPED && state != STOPPING)
		{
			setState( STOPPING);
		}
	}
	
	/* Method to be overridden by subclass, if necessary.
	 * Called once in the lifetime of the process.
	 */
	public void addListeners()
	{
	}

	public void run()
	{
		ServerSocket ss = null;
        try
		{
		    //add any listeners for the SerialPort
            addListeners();

			ss = new ServerSocket( tcpPort);

			// Setting SO_TIMEOUT allows us to check for termination
			// requests every so often.
			ss.setSoTimeout( 5000);
		}
		catch( IOException ioe)
		{
			return;
		}

		try
		{
			setState( RUNNING);
			while( state == RUNNING)
			{
				controlSocket = null;
				try
				{
				    //use this object array to gather up the DataInputStreams,
				    //that way we only have to create them once
				    Object[] datastreams = new Object[2];
				    
					// Listen for control socket connection
                    if( DEBUG) System.out.println( "Listening for control socket");
					controlSocket = accept(ss, 0, datastreams);
                    if( DEBUG) System.out.println( "Got control socket");
                    
					controlSocket.setTcpNoDelay( true);
					// Use double KEEP_ALIVE_TIME to allow for latency
					controlSocket.setSoTimeout(2 * KEEP_ALIVE_TIME);

					// Get control streams
					//DataInputStream cis  = (DataInputStream)  datastreams[0];
					//DataOutputStream cos = (DataOutputStream) datastreams[1];

					// Get new control streams
					DataInputStream cis  = new DataInputStream(cpis);
					DataOutputStream cos = new DataOutputStream(cpos);
					cis.readLine datastreams[0].toString();
					
					// Send port type
		            cos.writeInt( getPortType());

					// Read status and restart loop if it is not OK
					if( OK != cis.readInt()) 
					{
						controlSocket.close();
						continue;
					}

					try
					{
						initialize(ss);
					}
					catch( PortInUseException piue)
					{
						// Send exception
		                cos.writeInt(PORT_IN_USE_EXCEPTION);
						continue;
					}
					catch( IOException ioe)
					{
						// Send exception
		                cos.writeInt(IO_EXCEPTION);
						continue;
					}

					// Send OK
					cos.writeInt(OK);

					// Set state to CONNECTED
					setState(CONNECTED);

					// Handle connection
					handleConnection(cis, cos);
				}
				catch( IOException ioe)
				{
					// Assume connection has been terminated and no longer
					// needs to be handled.
                    if( DEBUG) System.out.println( "Caught IOException.  Terminating connection.");
					// Step down to RUNNING state IFF current state is CONNECTED
					synchronized( this)
					{
						if( state == CONNECTED)
						{
							setState( RUNNING);
						}
					}
				}
				// Stop on any other Exception.
				catch( Exception e)
				{
                    if( DEBUG) e.printStackTrace();
					stop();
				}
				finally
				{
					// Close any and all sockets that may have been opened
                    if( DEBUG) System.out.println( "Closing connection...");
					close();
                    if( DEBUG) System.out.println( "...Connection closed.");
				}
			}
            if( DEBUG) System.out.println( "RUNNING != state (" + state + ")" );
		}
		catch( RuntimeException re)
		{
			throw re;
		}
		finally
		{
			try 
			{ 
			    ss.close(); 
			}
			catch( IOException ioe) { /* Ignore */ }

            if( DEBUG) System.out.println( "Setting state to STOPPED.");

			setState( STOPPED);

            if( DEBUG) System.out.println( "CPS.run() returning...");
		}
        if( DEBUG) System.out.println( "...return is normal.");
	}

	protected synchronized void setState(int state)
	{
        if( DEBUG) System.out.println( "CommPortServer state change " + this.state + "->" + state);
		this.state = state;
		notifyAll();
	}

	protected void initialize( ServerSocket ss) throws IOException, PortInUseException
	{
		// Open comm port
        if (DEBUG) System.out.println( "Opening comm port");
        
        /*  try this...we are going to open the serial port upon construction 
            of the server, and not close it until the end...if we ever want to 
            open the server only when there is a request, this is where we
            need to do it

            cp = commPortIdentifier.open( "tcpcomm", 0);
            
            however, we should reset the commPort to default parameters...
        */

        try
        {
            ((SerialPort)cp).setSerialPortParams(2400, 8, 1, SerialPort.PARITY_EVEN);
            ((SerialPort)cp).setFlowControlMode(SerialPort.FLOWCONTROL_NONE);
        }
        catch(UnsupportedCommOperationException ucoe)
        {
            //this should not happen on TINI...these are the default params...
        }
     
	    try 
	    { 
		    cp.enableReceiveTimeout( 3000); 
	    }
	    catch (UnsupportedCommOperationException ucoe) 
	    { 
		    // Ignore 
	    }
        
        
        if (DEBUG) System.out.println( "Got comm port");

		// Set receive timeout to 1 second
        if( DEBUG) System.out.println( "Setting receive timeout to 1 second.");

		try
		{
		    Object[] datastreams = new Object[2];
		    
			// Get stream socket
            if( DEBUG) System.out.println( "Listening for streamSocket");
			streamSocket = accept( ss, STREAM_ID | controlSocket.getPort(), datastreams);
			
			streamSocketInputStream  = (DataInputStream) datastreams[0];
			streamSocketOutputStream = (DataOutputStream) datastreams[1];
			
            if( DEBUG) System.out.println( "Got stream socket");
			streamSocket.setTcpNoDelay( true);

			// Get event socket
            if( DEBUG) System.out.println( "Listening for eventSocket");
			eventSocket = accept( ss, EVENT_ID | controlSocket.getPort(), datastreams);

            eventSocketInputStream  = (DataInputStream) datastreams[0];
			eventSocketOutputStream = (DataOutputStream) datastreams[1];

            if( DEBUG) System.out.println( "Got event socket");
			eventSocket.setTcpNoDelay( true);
		}
		catch( IOException ioe)
		{
		    System.out.println("EXCEPTION IN INITIALIZE: "+ioe);
			cp.close();
			throw ioe;
		}
	}


    /* Once we have a connection we go here, and wait for requests from the client.
     * When we get requests, we perform them--they will be things like setDTR to 
     * true, set baud rate to 9600, etc.
     */
	protected void handleConnection( DataInputStream cis, DataOutputStream cos)	throws IOException
	{
		while( state == CONNECTED)
		{
			try
			{
                if( DEBUG) System.out.println( "----------");
				int cmd = cis.readInt();
				handleRequest( cmd, cis, cos);
			}
			catch( UnsupportedCommOperationException ucoe)
			{
				cos.writeInt(UNSUPPORTED_COMM_OPERATION_EXCEPTION);
				cos.writeUTF(ucoe.getMessage());
			}
		}
        if( DEBUG) System.out.println( "CPS.handleConnection() returning normally.");
	}

	protected void handleRequest(int cmd, DataInputStream cis, DataOutputStream cos)
	throws IOException, UnsupportedCommOperationException
	{
		int p0;
		int retVal = 0;

		switch( cmd)
		{
		    case KEEP_ALIVE:
			    // Do nothing
			    break;
		    case GET_INPUT_STREAM: