NumberSinkApplet.java

/*
 * Created on Mar 5, 2004
 */
package org.nees.rbnb;

import java.applet.Applet;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Date;
import java.util.TimeZone;
import java.text.SimpleDateFormat;

import com.rbnb.sapi.*;
//import COM.Creare.Utility.ArgHandler; //for argument parsing
import com.rbnb.utility.ArgHandler; //for argument parsing
//import COM.Creare.Utility.RBNBProcess; //alternative to System.exit, so
                                       //don't bring down servlet engine
import com.rbnb.utility.RBNBProcess; //alternative to System.exit, so
                                       //don't bring down servlet engine

public class NumberSinkApplet extends Applet {
    
    private static final String SERVER_NAME = "localhost";
    private static final String SERVER_PORT = "3333";
    private static final String SINK_NAME = "GetNumber";
    private static final String SOURCE_NAME = "RandomWalk";
    private static final String CHANNEL_NAME = "RandomWalkData";
    
    private static final SimpleDateFormat DATE_FORMAT = new SimpleDateFormat("MMM d, yyyy h:mm aa");
    private static final TimeZone TZ = TimeZone.getTimeZone("GMT");

    static
    {
        DATE_FORMAT.setTimeZone(TZ);
    }

    private String serverName = SERVER_NAME;
    private String serverPort = SERVER_PORT;
    private String server = serverName + ":" + serverPort;
    private String sinkName = SINK_NAME;
    private String sourceName = SOURCE_NAME;
    private String channelName = CHANNEL_NAME;
    private String requestPath = sourceName + "/" + channelName;
     
    Sink sink = null;
    ChannelMap sMap;
    int index;
    boolean connected = false;
    
    Thread stringDataThread;
    boolean runit = false;

    private void setArgs() {
        String serverName = SERVER_NAME;
        String serverPort = SERVER_PORT;
        String sinkName = SINK_NAME;
        String sourceName = SOURCE_NAME;
        String channelName = CHANNEL_NAME;
        String param;

        param = getParameter("serverName");
        if (param != null)
            serverName = param;
        
        param = getParameter("serverPort");
        if (param != null)
            serverPort = param;
        
        param = getParameter("sinkName");
        if (param != null)
            sinkName = param;

        param = getParameter("sourceName");
        if (param != null)
            sourceName = param;

        param = getParameter("channelName");
        if (param != null)
            channelName = param;

        setArgs(serverName,serverPort,sinkName,sourceName,channelName);     
    }

    private void setArgs(String serverName, String serverPort,
        String sinkName, String sourceName, String channelName)
    {
        this.serverName = serverName;
        this.serverPort = serverPort;
        
        server = serverName + ":" + serverPort;
    
        setArgs(server,sinkName,sourceName,channelName);
    }

    private void setArgs(String server, String sinkName,
        String sourceName, String channelName)
    {
        this.server = server;
        serverText.setText(server);
        
        this.sinkName = sinkName;
        sinkText.setText(sinkName);

        this.sourceName = sourceName;
        sourceText.setText(sourceName);
        
        this.channelName = channelName;
        channelText.setText(channelName);
        
        requestPath = sourceName + "/" + channelName;
        
    }

    private void setArgsFromTextFields()
    {
        setArgs (   
            serverText.getText(),
            sinkText.getText(),
            sourceText.getText(),
            channelText.getText()
        );
    }
    
    public void openConnection()
    {
        if (connected) return;
        
        try {
            disableStart();
            setArgsFromTextFields();
            messagePanel.message("Attempting connection to server...");
            // Create a sink and connect:
            sink=new Sink();
            sink.OpenRBNBConnection(server,sinkName);
            sMap = new ChannelMap();
            index = sMap.Add(requestPath);
            sink.Subscribe(sMap,"newest");
            connected = true;
            messagePanel.message("Connection made to server...");
            messagePanel.message("on " + server + " as " + sinkName);
            messagePanel.message("  Requesting " + requestPath);
            enableStart();
            start();
            connectButton.setLabel(DISCONNECT);
            connectButton.setActionCommand(connectButton.getLabel());
        }
        catch (SAPIException se)
        {
            messagePanel.message("SAPIException = " + se);
        }
    }
    
    private void enableStart() {
        startStopButton.setEnabled(true);
    }

    private void disableStart() {
        startStopButton.setEnabled(false);
    }

    private void closeConnection()
    {
        if (!connected) return;
        stop();
        disableStart();
        connected = false;
        sink.CloseRBNBConnection();
        connectButton.setLabel(CONNECT);
        connectButton.setActionCommand(connectButton.getLabel());
    }

    public void startThread()
    {
        
        if (!connected) return;
        
        // Use this inner class to hide the public run method
        Runnable r = new Runnable() {
            public void run() {
              runWork();
            }
        };
        runit = true;
        stringDataThread = new Thread(r, "StringData");
        stringDataThread.start();
        messagePanel.message("NumberSink: Started thread.");
    }

    public void stopThread()
    {
        runit = false;
        stringDataThread.interrupt();
        messagePanel.message("NumberSink: Stopped thread.");
    }
    
    private void runWork ()
    {
        try {
            while(isRunning())
            {
                ChannelMap m = sink.Fetch(-1);
                if (m == null)
                {
                    messagePanel.message("Data fetch failed.");
                    continue;
                }
                double timeStamp = m.GetTimeStart(index);
                double[] data = m.GetDataAsFloat64(index);
                long unixTime = (long)(timeStamp * 1000.0); // convert sec to millisec
                String time = DATE_FORMAT.format(new Date(unixTime));
                messagePanel.message("Data Received (for " + time + " GMT): ");
                for (int i = 0; i < data.length; i++)
                {
                    messagePanel.message("  " + i + ": " + data[i]);
                }
            }
        } catch (SAPIException se) {
            se.printStackTrace(); 
        }
        stringDataThread = null;
    }
    
    public boolean isRunning()
    {
        return (connected && runit);
    }

    public void init() {
        setArgs();
        setLayout();
        repaint();
        messagePanel.message("initializing... ");
        messagePanel.message("Starting NumberSinkAppler on " + server + " as " + sinkName);
        messagePanel.message("  Requesting " + requestPath);
    }

    public void start() {
        messagePanel.message("starting... ");
        startThread();
        startStopButton.setLabel(STOP);
        startStopButton.setActionCommand(startStopButton.getLabel());
    }

    public void stop() {
        messagePanel.message("stopping... ");
        stopThread();
        startStopButton.setLabel(START);
        startStopButton.setActionCommand(startStopButton.getLabel());
    }

    public void destroy() {
        messagePanel.message("preparing for unloading...");
        closeConnection();
    }

    private static final String CONNECT = "Connect";
    private static final String DISCONNECT = "Disconnect";
    private Button connectButton = new Button(CONNECT);
    
    private static final String START = "Start";
    private static final String STOP = "Stop";
    private Button startStopButton = new Button(START);
    
    private TextField serverText =
        new TextField(SERVER_NAME + ":" + SERVER_PORT,40);
    private TextField sinkText = new TextField(SINK_NAME,40);
    private TextField sourceText = new TextField(SOURCE_NAME,40);
    private TextField channelText = new TextField(CHANNEL_NAME,40);

    MessagePanel messagePanel = new MessagePanel();

    private void setLayout()
    {
        setLayout(new BorderLayout());      

        Panel p = new Panel();
        p.setLayout(new GridLayout(2,4));
        p.add(serverText);
        p.add(new Label("Server Host : port"));
        p.add(sinkText);
        p.add(new Label("Sink Name"));
        p.add(sourceText);
        p.add(new Label("Source Name"));
        p.add(channelText);
        p.add(new Label("Channel Name"));
        add("North",p);
            
        p = new Panel();
        p.add(connectButton);
        p.add(startStopButton);     
        add("South", p);
        
        p = new Panel();
        p.add(messagePanel);
        add("Center", p);
    
        startStopButton.setEnabled(false);
        startStopButton.setActionCommand(startStopButton.getLabel());
        startStopButton.addActionListener(
            new ActionListener() {
                public void actionPerformed(ActionEvent ev) {
                    startStopAction(ev.getActionCommand());
                }
            }
        );
        
        connectButton.setActionCommand(connectButton.getLabel());
        connectButton.addActionListener(
            new ActionListener() {
                public void actionPerformed(ActionEvent ev) {
                    connectAction(ev.getActionCommand());
                }
            }
        );
    
    }
    
    private void startStopAction(String command)
    {
        if (command.equals(STOP))
            stop();
        else
            start();
    }

    private void connectAction(String command)
    {
        if (command.equals(CONNECT))
            openConnection();
        else
            closeConnection();
    }
}

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