I know that in J2ME CommConnection is the connection to use when working with serial port. I know there are the openInputStream and openOutputStream methods , but in fact I don't know how to transfer data from my MIDLet to the COM port ( the USB port into which the phone's cable is inserted , the phone is Alcatel OT-806D ). For example I want to send the text "Hello world". How to achieve that ?
Here are codes :
J2ME :
import java.io.IOException;
import java.io.OutputStream;
import javax.microedition.io.CommConnection;
import javax.microedition.io.Connector;
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.midlet.*;
public class SerialPortMidlet extends MIDlet implements CommandListener, Runnable {
private Command upload = new Command("upload", Command.SCREEN, 0);
private Command exit = new Command("exit", Command.SCREEN, 1);
private Form f = new Form("test serial port");
private Thread uploadThread;
private CommConnection com;
private OutputStream os;
public SerialPortMidlet()
{
f.addCommand(upload);
f.addCommand(exit);
f.setCommandListener(this);
uploadThread = new Thread(this);
}
public void startApp() {
Display.getDisplay(this).setCurrent(f);
}
public void pauseApp() {
}
public void destroyApp(boolean unconditional) {
notifyDestroyed();
}
public void commandAction(Command c, Displayable d) {
if (c == upload)
{
uploadThread.start();
f.removeCommand(upload);
}
else if (c == exit)
{
if (uploadThread.isAlive())
{
uploadThread.interrupt();
try {
uploadThread.join();
} catch (InterruptedException ex) {
ex.printStackTrace();
}
}
destroyApp(true);
}
}
public void run() {
try
{
String s = new String("andrana mandefa lavaka");
com = (CommConnection) Connector.open("comm:COM4");
os = com.openOutputStream();
os.write(s.getBytes());
os.close();
}
catch (IOException ex)
{
ex.printStackTrace();
}
}
}
J2SE : ( Eclipse )
import gnu.io.CommPort;
import gnu.io.CommPortIdentifier;
import gnu.io.SerialPort;
import gnu.io.SerialPortEvent;
import gnu.io.SerialPortEventListener;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
public class TwoWaySerialComm
{
public TwoWaySerialComm()
{
super();
}
void connect ( String portName ) throws Exception
{
CommPortIdentifier portIdentifier = CommPortIdentifier.getPortIdentifier(portName);
if ( portIdentifier.isCurrentlyOwned() )
{
System.out.println("Error: Port is currently in use");
}
else
{
CommPort commPort = portIdentifier.open(this.getClass().getName(),2000);
if ( commPort instanceof SerialPort )
{
SerialPort serialPort = (SerialPort) commPort;
serialPort.setSerialPortParams(57600,SerialPort.DATABITS_8,SerialPort.STOPBITS_1,SerialPort.PARITY_NONE);
InputStream in = serialPort.getInputStream();
OutputStream out = serialPort.getOutputStream();
(new Thread(new SerialWriter(out))).start();
serialPort.addEventListener(new SerialReader(in));
serialPort.notifyOnDataAvailable(true);
}
else
{
System.out.println("Error: Only serial ports are handled by this example.");
}
}
}
public static class SerialReader implements SerialPortEventListener
{
private InputStream in;
private byte[] buffer = new byte[1024];
public SerialReader ( InputStream in )
{
this.in = in;
}
public void serialEvent(SerialPortEvent arg0) {
int data;
try
{
int len = 0;
while ( ( data = in.read()) > -1 )
{
if ( data == '\n' ) {
break;
}
buffer[len++] = (byte) data;
}
System.out.print(new String(buffer,0,len));
}
catch ( IOException e )
{
e.printStackTrace();
System.exit(-1);
}
}
}
public static class SerialWriter implements Runnable
{
OutputStream out;
public SerialWriter ( OutputStream out )
{
this.out = out;
}
public void run ()
{
try
{
int c = 0;
while ( ( c = System.in.read()) > -1 )
{
this.out.write(c);
}
}
catch ( IOException e )
{
e.printStackTrace();
System.exit(-1);
}
}
}
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
try
{
(new TwoWaySerialComm()).connect("COM1");
}
catch ( Exception e )
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
I run the J2SE program , I inserted the mobile phone cable into the computer ( in the USB slot ) , I clicked the upload command in the J2ME app , but there is nothing in the output screen of the eclipse !
So what's the problem ?
I run this J2SE code to detect the port on which the phone's cable is :
import gnu.io.*;
public class SerialPortLister {
/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
listPorts();
}
private static void listPorts()
{
@SuppressWarnings("unchecked")
java.util.Enumeration<CommPortIdentifier> portEnum = CommPortIdentifier.getPortIdentifiers();
while ( portEnum.hasMoreElements() )
{
CommPortIdentifier portIdentifier = portEnum.nextElement();
System.out.println(portIdentifier.getName() + " - " + getPortTypeName(portIdentifier.getPortType()) );
}
}
private static String getPortTypeName ( int portType )
{
switch ( portType )
{
case CommPortIdentifier.PORT_I2C:
return "I2C";
case CommPortIdentifier.PORT_PARALLEL:
return "Parallel";
case CommPortIdentifier.PORT_RAW:
return "Raw";
case CommPortIdentifier.PORT_RS485:
return "RS485";
case CommPortIdentifier.PORT_SERIAL:
return "Serial";
default:
return "unknown type";
}
}
}
And it shows COM4 because when I detach the cable then only COM1 and LPT1 are displayed.
So what's the problem ?