serialdemo.java

利用java实现串口通信,两个用户可以通过一条线实现数据的发送

    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");
        }

        newProps.save(fileOut, "Serial Demo poperties");

        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("端口名:", Label.LEFT);
	    add(portNameLabel);

	    portChoice = new Choice();
	    portChoice.addItemListener(this);
	    add(portChoice);
	    listPortChoices();
	    portChoice.select(parameters.getPortName());
	    
	    baudLabel = new Label("波特率:", 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("输入流管理:", 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("输出流管理:", 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("数据位:", 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("停止位:", 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("奇偶校验:", 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;
	
	public CloseHandler(SerialDemo sd) {
	    this.sd = sd;
	}

	public void windowClosing(WindowEvent e) {
	    sd.shutdown();
	}
    }
}