Reading response of AT command

Question

I am using this code. I should get OK as output. But I only get few squares as output. Please help me fix this code. Thanks.
import javax.comm.*;
import java.io.*;
import java.util.*;
public class try1 {
public static void main(String args[]) {
InputStream input = null;
OutputStream output = null;
SerialPort serialPort = null;
try {
CommPortIdentifier portId = CommPortIdentifier.getPortIdentifier("COM1");
serialPort = (SerialPort) portId.open("SimpleReadApp", 2000);
System.out.println("sdiosdfdsf");
String f=null;int n;
input = serialPort.getInputStream();
output = serialPort.getOutputStream();
Thread readThread;
serialPort.notifyOnDataAvailable(true);
try {
serialPort.setSerialPortParams(9600, SerialPort.DATABITS_8,
SerialPort.STOPBITS_1,
SerialPort.PARITY_NONE);
} catch (UnsupportedCommOperationException e) {}
output.write("AT\r\n".getBytes());
Thread.sleep(20000);
byte[] readBuffer = new byte[120];
try {
while (input.available() > 0) {
int numBytes = input.read(readBuffer);
System.out.print(new String(readBuffer));
} catch (IOException e) {}
// output.flush();
// int y;
//y=input.available();
// System.out.println("df"+y);
} catch (NoSuchPortException e) {
System.out.println("Exception in Adding Listener" + e);
} catch (PortInUseException e) {
System.out.println("Exception in Adding Listener" + e);
} catch (IOException e) {
System.out.println("Exception in Adding Listener" + e);
catch (InterruptedException e) {
System.out.println("Exception in Adding Listener" + e);
}

Answer 1

Hi Friends,
I have also similar kind of query.
How we can interact with SIM using AT commands?
I know few details about AT commands interaction with modem in native development(Using C).
But i dont have any idea in Java card applet. I am quite new to java card development.
Any response/suggestion will bi highly appreciated and will be of great help.
Thanks in advance for the help.
Best Regards,
Sunil K