Socket MIDlet


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); } }