serialdemo.java

java communications api 3.0

    /**
     * Writes the current parameters to a configuration file of the
     * java.properties style.
     */
    private void writeFile(String path) {
	Properties       newProps;
	FileOutputStream fileOut = null;

	newProps = new Properties();

	newProps.put("portName", parameters.getPortName());
	newProps.put("baudRate", parameters.getBaudRateString());
	newProps.put("flowControlIn", parameters.getFlowControlInString());
	newProps.put("flowControlOut", parameters.getFlowControlOutString());
	newProps.put("parity", parameters.getParityString());
	newProps.put("databits", parameters.getDatabitsString());
	newProps.put("stopbits", parameters.getStopbitsString());

	try {
	    fileOut = new FileOutputStream(path);
	} catch (IOException e) {
	    System.out.println("Could not open file for writiing");
	} 

	try {
	   writeProps(newProps,"Serial Demo poperties");
	} catch(Exception e) {
	}
	
	try {
	    fileOut.close();
	} catch (IOException e) {
	    System.out.println("Could not close file for writiing");
	} 
    } 

    /**
     * Cleanly shuts down the applicaion. first closes any open ports and
     * cleans up, then exits.
     */
    private void shutdown() {
	connection.closeConnection();
	System.exit(1);
    } 

    /**
     * Finds configuration file in arguments and creates a properties object from
     * that file.
     */
    private void parseArgs(String[] args) {
	if (args.length < 1) {
	    return;
	} 

	File f = new File(args[0]);

	if (!f.exists()) {
	    f = new File(System.getProperty("user.dir") 
			 + System.getProperty("path.separator") + args[0]);
	} 

	if (f.exists()) {
	    try {
		FileInputStream fis = new FileInputStream(f);

		props = new Properties();

		props.load(fis);
		fis.close();
		loadParams();
	    } catch (IOException e) {}
	} 
    } 

    /**
     * Set the parameters object to the settings in the properties object.
     */
    private void loadParams() {
	parameters.setPortName(props.getProperty("portName"));
	parameters.setBaudRate(props.getProperty("baudRate"));
	parameters.setFlowControlIn(props.getProperty("flowControlIn"));
	parameters.setFlowControlOut(props.getProperty("flowControlOut"));
	parameters.setParity(props.getProperty("parity"));
	parameters.setDatabits(props.getProperty("databits"));
	parameters.setStopbits(props.getProperty("stopbits"));
	setConfigurationPanel();
    } 
    
    /**
     * GUI element that holds the user changable elements for connection
     * configuration.
     */
    class ConfigurationPanel extends Panel implements ItemListener {
	private Frame  parent;
	private Label  portNameLabel;
	private Choice portChoice;
	private Label  baudLabel;
	private Choice baudChoice;
	private Label  flowControlInLabel;
	private Choice flowChoiceIn;
	private Label  flowControlOutLabel;
	private Choice flowChoiceOut;
	private Label  databitsLabel;
	private Choice databitsChoice;
	private Label  stopbitsLabel;
	private Choice stopbitsChoice;
	private Label  parityLabel;
	private Choice parityChoice;

	/**
	 * Creates and initilizes the configuration panel. The initial settings
	 * are from the parameters object.
	 */
	public ConfigurationPanel(Frame parent) {
	    this.parent = parent;

	    setLayout(new GridLayout(4, 4));

	    portNameLabel = new Label("Port Name:", Label.LEFT);

	    add(portNameLabel);

	    portChoice = new Choice();

	    portChoice.addItemListener(this);
	    add(portChoice);
	    listPortChoices();
	    portChoice.select(parameters.getPortName());

	    baudLabel = new Label("Baud Rate:", Label.LEFT);

	    add(baudLabel);

	    baudChoice = new Choice();

	    baudChoice.addItem("300");
	    baudChoice.addItem("2400");
	    baudChoice.addItem("9600");
	    baudChoice.addItem("14400");
	    baudChoice.addItem("28800");
	    baudChoice.addItem("38400");
	    baudChoice.addItem("57600");
	    baudChoice.addItem("152000");
	    baudChoice.select(Integer.toString(parameters.getBaudRate()));
	    baudChoice.addItemListener(this);
	    add(baudChoice);

	    flowControlInLabel = new Label("Flow Control In:", Label.LEFT);

	    add(flowControlInLabel);

	    flowChoiceIn = new Choice();

	    flowChoiceIn.addItem("None");
	    flowChoiceIn.addItem("Xon/Xoff In");
	    flowChoiceIn.addItem("RTS/CTS In");
	    flowChoiceIn.select(parameters.getFlowControlInString());
	    flowChoiceIn.addItemListener(this);
	    add(flowChoiceIn);

	    flowControlOutLabel = new Label("Flow Control Out:", Label.LEFT);

	    add(flowControlOutLabel);

	    flowChoiceOut = new Choice();

	    flowChoiceOut.addItem("None");
	    flowChoiceOut.addItem("Xon/Xoff Out");
	    flowChoiceOut.addItem("RTS/CTS Out");
	    flowChoiceOut.select(parameters.getFlowControlOutString());
	    flowChoiceOut.addItemListener(this);
	    add(flowChoiceOut);

	    databitsLabel = new Label("Data Bits:", Label.LEFT);

	    add(databitsLabel);

	    databitsChoice = new Choice();

	    databitsChoice.addItem("5");
	    databitsChoice.addItem("6");
	    databitsChoice.addItem("7");
	    databitsChoice.addItem("8");
	    databitsChoice.select(parameters.getDatabitsString());
	    databitsChoice.addItemListener(this);
	    add(databitsChoice);

	    stopbitsLabel = new Label("Stop Bits:", Label.LEFT);

	    add(stopbitsLabel);

	    stopbitsChoice = new Choice();

	    stopbitsChoice.addItem("1");
	    stopbitsChoice.addItem("1.5");
	    stopbitsChoice.addItem("2");
	    stopbitsChoice.select(parameters.getStopbitsString());
	    stopbitsChoice.addItemListener(this);
	    add(stopbitsChoice);

	    parityLabel = new Label("Parity:", Label.LEFT);

	    add(parityLabel);

	    parityChoice = new Choice();

	    parityChoice.addItem("None");
	    parityChoice.addItem("Even");
	    parityChoice.addItem("Odd");
	    parityChoice.select("None");
	    parityChoice.select(parameters.getParityString());
	    parityChoice.addItemListener(this);
	    add(parityChoice);
	}

	/**
	 * Sets the configuration panel to the settings in the parameters object.
	 */
	public void setConfigurationPanel() {
	    portChoice.select(parameters.getPortName());
	    baudChoice.select(parameters.getBaudRateString());
	    flowChoiceIn.select(parameters.getFlowControlInString());
	    flowChoiceOut.select(parameters.getFlowControlOutString());
	    databitsChoice.select(parameters.getDatabitsString());
	    stopbitsChoice.select(parameters.getStopbitsString());
	    parityChoice.select(parameters.getParityString());
	} 

	/**
	 * Sets the parameters object to the settings in the configuration panel.
	 */
	public void setParameters() {
	    parameters.setPortName(portChoice.getSelectedItem());
	    parameters.setBaudRate(baudChoice.getSelectedItem());
	    parameters.setFlowControlIn(flowChoiceIn.getSelectedItem());
	    parameters.setFlowControlOut(flowChoiceOut.getSelectedItem());
	    parameters.setDatabits(databitsChoice.getSelectedItem());
	    parameters.setStopbits(stopbitsChoice.getSelectedItem());
	    parameters.setParity(parityChoice.getSelectedItem());
	} 

	/**
	 * Sets the elements for the portChoice from the ports available on the
	 * system. Uses an emuneration of comm ports returned by
	 * CommPortIdentifier.getPortIdentifiers(), then sets the current
	 * choice to a mathing element in the parameters object.
	 */
	void listPortChoices() {
	    CommPortIdentifier portId;
	    Enumeration	       en = CommPortIdentifier.getPortIdentifiers();

	    // iterate through the ports.
	    while (en.hasMoreElements()) {
		portId = (CommPortIdentifier) en.nextElement();

		if (portId.getPortType() == CommPortIdentifier.PORT_SERIAL) {
		    portChoice.addItem(portId.getName());
		} 
	    } 

	    portChoice.select(parameters.getPortName());
	} 

	/**
	 * Event handler for changes in the current selection of the Choices.
	 * If a port is open the port can not be changed.
	 * If the choice is unsupported on the platform then the user will
	 * be notified and the settings will revert to their pre-selection
	 * state.
	 */
	public void itemStateChanged(ItemEvent e) {

	    // Check if port is open.
	    if (connection.isOpen()) {

		// If port is open do not allow port to change.
		if (e.getItemSelectable() == portChoice) {

		    // Alert user.
		    AlertDialog ad = new AlertDialog(parent, "Port Open!", 
						     "Port can not", 
						     "be changed", 
						     "while a port is open.");

		    // Return configurationPanel to pre-choice settings.
		    setConfigurationPanel();

		    return;
		} 

		// Set the parameters from the choice panel.
		setParameters();

		try {

		    // Attempt to change the settings on an open port.
		    connection.setConnectionParameters();
		} catch (SerialConnectionException ex) {

		    // If setting can not be changed, alert user, return to
		    // pre-choice settings.
		    AlertDialog ad = 
			new AlertDialog(parent, "Unsupported Configuration!", 
					"Configuration Parameter unsupported,", 
					"select new value.", 
					"Returning to previous configuration.");

		    setConfigurationPanel();
		} 
	    } else {

		// Since port is not open just set the parameter object.
		setParameters();
	    } 
	} 


    }

    /**
     * Handles closing down system. Allows application to be closed with window
     * close box.
     */
    class CloseHandler extends WindowAdapter {
	SerialDemo sd;

	/**
	 * Constructor declaration
	 *
	 *
	 * @param sd
	 *
	 * @see
	 */
	public CloseHandler(SerialDemo sd) {
	    this.sd = sd;
	}

	/**
	 * Method declaration
	 *
	 *
	 * @param e
	 *
	 * @see
	 */
	public void windowClosing(WindowEvent e) {
	    sd.shutdown();
	} 

    }

}