package ora.ch6;import java.io.InputStream;import java.io.IOException;import java.io.OutputStream;import javax.microedition.io.Connector;import javax.microedition.io.StreamConnection;import javax.microedition.lcdui.Alert;import javax.microedition.lcdui.AlertType;import javax.microedition.lcdui.Command;import javax.microedition.lcdui.CommandListener;import javax.microedition.lcdui.Display;import javax.microedition.lcdui.Displayable;import javax.microedition.lcdui.Form;import javax.microedition.lcdui.StringItem;import javax.microedition.lcdui.TextField;import javax.microedition.midlet.MIDlet;import javax.microedition.midlet.MIDletStateChangeException;public class SocketMIDlet extends MIDlet                    implements CommandListener, Runnable {    private Display display;    private Form addressForm;    private Form connectForm;    private Form displayForm;    private TextField serverName;    private TextField serverPort;    private StringItem messageLabel;    private StringItem errorLabel;    private Command okCommand;    private Command exitCommand;    private Command backCommand;    protected void startApp() throws MIDletStateChangeException {        if (display == null) {            initialize();            display.setCurrent(addressForm);        }    }    protected void pauseApp() {    }    protected void destroyApp(boolean unconditional)                        throws MIDletStateChangeException {    }    public void commandAction(Command cmd, Displayable d) {        if (cmd == okCommand) {            Thread t = new Thread(this);            t.start();            display.setCurrent(connectForm);        } else if (cmd == backCommand) {            display.setCurrent(addressForm);        } else if (cmd == exitCommand) {            try {                destroyApp(true);            } catch (MIDletStateChangeException ex) {            }            notifyDestroyed();        }    }    public void run() {        InputStream is = null;        OutputStream os = null;        StreamConnection socket = null;        try {            String server = serverName.getString();            String port = serverPort.getString();            String name = "socket://" + server + ":" + port;            socket = (StreamConnection)Connector.open(name, Connector.READ_WRITE);        } catch (Exception ex) {            Alert alert = new Alert("Invalid Address",                        "The supplied address is invalid\n" +                        "Please correct it and try again.", null,                        AlertType.ERROR);            alert.setTimeout(Alert.FOREVER);            display.setCurrent(alert, addressForm);            return;        }        try {            // Send a message to the server            String request = "GET / HTTP/1.0\n\n";            os = socket.openOutputStream();            os.write(request.getBytes());            os.close();            // Read the server's reply, up to a maximum            // of 128 bytes.            is = socket.openInputStream();            final int MAX_LENGTH = 128;            byte[] buf = new byte[MAX_LENGTH];            int total = 0;            while (total < MAX_LENGTH) {                int count = is.read(buf, total, MAX_LENGTH - total);                if (count < 0) {                    break;                }                total += count;            }            is.close();            String reply = new String(buf, 0, total);            messageLabel.setText(reply);            socket.close();            display.setCurrent(displayForm);        } catch (IOException ex) {            Alert alert = new Alert("I/O Error",                        "An error occurred while communicating with the server.",                        null, AlertType.ERROR);            alert.setTimeout(Alert.FOREVER);            display.setCurrent(alert, addressForm);            return;        } finally {            // Close open streams and the socket            try {                if (is != null) {                    is.close();                    is = null;                }            } catch (IOException ex1) {            }            try {                if (os != null) {                    os.close();                    os = null;                }            } catch (IOException ex1) {            }            try {                if (socket != null) {                    socket.close();                    socket = null;                }            } catch (IOException ex1) {            }        }    }    private void initialize() {        display = Display.getDisplay(this);        // Commands        exitCommand = new Command("Exit", Command.EXIT, 0);        okCommand = new Command("OK", Command.OK, 0);        backCommand = new Command("Back", Command.BACK, 0);        // The address form        addressForm = new Form("Socket Client");        serverName = new TextField("Server name:", "", 256, TextField.ANY);        serverPort = new TextField("Server port:", "", 8, TextField.NUMERIC);        addressForm.append(serverName);        addressForm.append(serverPort);        addressForm.addCommand(okCommand);        addressForm.addCommand(exitCommand);        addressForm.setCommandListener(this);        // The connect form        connectForm = new Form("Connecting");        messageLabel = new StringItem(null, "Connecting...\nPlease wait.");        connectForm.append(messageLabel);        connectForm.addCommand(backCommand);        connectForm.setCommandListener(this);        // The display form        displayForm = new Form("Server Reply");        messageLabel = new StringItem(null, null);        displayForm.append(messageLabel);        displayForm.addCommand(backCommand);        displayForm.setCommandListener(this);    }}