J2ME Error

cyberwit

I have the following midlet calling a web service and retrieving results however i am getting the following error can anyone help


java.lang.IllegalMonitorStateException

import javax.microedition.midlet.MIDlet;
import javax.microedition.midlet.MIDletStateChangeException;

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import ie.travel.webservice.*;
public class Travel extends MIDlet {
	 private Display display;
	    private Command exit;
	    private Command submit;
	    private TextBox employeetextbox;
	    private AdministrationService_Stub admin;
	    private Form form;
	    private StringItem stringItem;
	public Travel() {
		exit = new Command("Exit",Command.EXIT,0);
        submit = new Command("Submit",Command.OK,1);
        form = new Form("Travel 2.0 Web Services");
        employeetextbox = new TextBox("Employee","",5,0);
        admin= new AdministrationService_Stub();
	}

	protected void destroyApp(boolean arg0) throws MIDletStateChangeException {
		// TODO Auto-generated method stub

	}

	protected void pauseApp() {
		// TODO Auto-generated method stub

	}

	protected void startApp() throws MIDletStateChangeException {
		// TODO Auto-generated method stub
		  display = Display.getDisplay(this);
	        display.setCurrent(employeetextbox);
	        
	       
	       try{
	      employeetextbox.setString("2001");
	      String employee = employeetextbox.getString();
	      String result=admin.getEmployee(employee);
	      Alert alert = new Alert("Result",result,null,null);
		  display.wait(5000);
	      display.setCurrent(alert);
	       }
	       catch(Exception ex){
	       Alert alert = new Alert("Error","ex"+ex,null,null);
	       System.out.println(ex);
	       display.setCurrent(alert);
	       }
	}

}

hussey

cyberwit wrote: »

java.lang.IllegalMonitorStateException

have you got the trace (for a few lines at least)

so we can identify which lines causes it?

change System.out.println(ex);
to
ex.printStackTrace(System.err);

marco_polo

You need to own the object lock to call wait () or notify on an object. You can do this by wrapping the call in a synchronized block.

synchronized (display) {   
      display.wait(5000);   
 }

If all you doing is pausing the thread for 5 seconds you should use a call to Thread.sleep(5000) instead (no need for synchronized block in this case)