Javax.microedition.lcdui.TextField.setChars exception

Question

Hi
I am developing an application for Mobile Banking for my College Project the program need to send an SMS with the Name and PIN no. I am using Sun WTK 2.3 the program compiles and preverifies correctly but when the Submit button is pressed an Illegal exception is thrown.
java.lang.IllegalArgumentException
     at javax.microedition.lcdui.TextField.setChars(+105)
     at javax.microedition.lcdui.TextField.setString(+27)
     at CheckBal.commandAction(+157)
     at javax.microedition.lcdui.Display$DisplayAccessor.commandAction(+282)
     at javax.microedition.lcdui.Display$DisplayManagerImpl.commandAction(+10)
     at com.sun.midp.lcdui.DefaultEventHandler.commandEvent(+68)
     at com.sun.midp.lcdui.AutomatedEventHandler.commandEvent(+47)
     at com.sun.midp.lcdui.DefaultEventHandler$QueuedEventHandler.run(+250)
This is the code.....
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import java.io.IOException.*;
import javax.microedition.io.*;
import javax.wireless.messaging.*;
public class CheckBal extends MIDlet implements CommandListener
private Form form;
private Command exit;
private Command submit;
private Display display;
TextField t1;
TextField t2;
public CheckBal()
display = Display.getDisplay(this);
exit = new Command("Exit", Command.EXIT, 1);
submit = new Command("Submit", Command.OK, 1);
form = new Form("Check Balance");
public void startApp()
t1 = new TextField("First Name:", "",30, TextField.ANY);
t2 = new TextField("Enter PIN:", "",4, TextField.ANY);
form.addCommand(exit);
form.addCommand(submit);
form.append(t1);
form.append(t2);
form.setCommandListener(this);
display.setCurrent(form);
public void pauseApp()
public void destroyApp(boolean unconditional)
public void commandAction(Command command, Displayable displayable)
if (command == exit)
destroyApp(false);
notifyDestroyed();
if (command == submit)
try{
try{
String s1 = t1.getString();
     String s2 = t2.getString();
     String s3 = s1+s2;
MessageConnection conn = (MessageConnection)Connector.open("sms://:[phone]");
     TextMessage msg = (TextMessage)conn.newMessage(MessageConnection.TEXT_MESSAGE);
     msg.setPayloadText(s3+ " Balance");
     conn.send(msg);
} catch(Exception e) {
t1.setString(e.toString());
     e.printStackTrace();
catch(Exception ee) {
t2.setString(ee.toString());
catch(Error ee) {
t2.setString(ee.toString());
}

Answer 1

Once again: you might want to look at some examples that are already out there.
The IllegalArgumentException is throws in the midlet, judging by the stacktrace, so saying it orriginates from the servlet is not possible.
Please do some more debugging. Check what you are sending, getting back and print some stuff in logs...
Make sure the servlet works first: test it simply in your webbrowser, then try to get the midlet working.
One tip: never count on length beeing more than -1, so simply do not use it!
InputStream in = ...
ByteArrayOutputStream bout = new ByteArrayOutputStream();
byte[] buffer = new byte[512];
int bs;
while((bs = in.read(buffer)!=-1){
   bout.write(buffer,0,bs);
String response = bout.toString();Much faster and works always.