Problems with "SecondMidletServlet.java"

Question

Hi guys, I'm now trying to use MIDlet to connnect a servlet which will retrieve the data from MS Access database.
I had tried the sample programs(First & SecondMidletServlet) in this site. It's fine for me to run the "FirstMidletServlet.java"... but I need the more advance method - POST. When I run "SecondMidletServlet.java", the MIDlet program is stopped after I click the 'submit' button where the program asking me "Is it OK to use airtime?"... Even i choose 'Yes', it doesn't work..
Do anyone could help? Please kindly tell me what's the problem behind.... Thanks!!!

Answer 1

Yes, here it's:
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import javax.microedition.io.*;
import java.io.*;
* An example MIDlet with simple "Hello" text and an Exit command.
* Refer to the startApp, pauseApp, and destroyApp
* methods so see how each handles the requested transition.
* @author  Ken_2
* @version
public class GetNpost extends MIDlet implements CommandListener {
    private Display display;    // The display for this MIDlet
    private Form fmMain;
    private Alert alError;
    private Command cmGET;
    private Command cmPOST;
    private Command cmExit;   // The exit command
    private TextField tfAcct;
    private TextField tfPwd;
    private StringItem siBalance;
    private String errorMsg = null;
    public GetNpost() {
        display = Display.getDisplay(this);
        //Create Command
        cmGET = new Command ("GET", Command.SCREEN, 2);
        cmPOST = new Command ("POST", Command.SCREEN, 3);
        cmExit = new Command("Exit", Command.SCREEN, 1);
        // Textfields
        tfAcct = new TextField("Account:",  "", 5,  TextField.NUMERIC);
        tfPwd = new TextField("Password:", "", 10,  TextField.ANY | TextField.PASSWORD);
        //Balance string item
        siBalance = new StringItem("Balance: $","");
        // Create Form, add commands & Components, listen for events
        fmMain = new Form("Account Information");
        fmMain.addCommand(cmExit);
        fmMain.addCommand(cmGET);
        fmMain.addCommand(cmPOST);
        fmMain.append(tfAcct);
        fmMain.append(tfPwd);
        fmMain.append(siBalance);
        fmMain.setCommandListener(this);
     * Start up the Hello MIDlet by creating the TextBox and associating
     * the exit command and listener.
    public void startApp() {  
        display.setCurrent(fmMain);
     * Pause is a no-op since there are no background activities or
     * record stores that need to be closed.
    public void pauseApp() {
     * Destroy must cleanup everything not handled by the garbage collector.
     * In this case there is nothing to cleanup.
    public void destroyApp(boolean unconditional) {
     * Respond to commands, including exit
     * On the exit command, cleanup and notify that the MIDlet has been destroyed.
    public void commandAction(Command c, Displayable s) {
        if (c == cmGET || c == cmPOST) {
            try
                if (c == cmGET)
                    lookupBalance_withGET();
                else
                    lookupBalance_withPOST();
            catch (Exception e)
                System.err.println("Msg: " + e.toString());
        else if (c == cmExit)
            destroyApp(false);
            notifyDestroyed();
     * Access servlet using GET
    private void lookupBalance_withGET() throws IOException
        HttpConnection http = null;
        InputStream iStrm = null;
        boolean ret = false;
        // Data is passed at the end of url for GET
        String url = "http://ismt.no-ip.com/servlet/DRMfypGroup2.GetNpostServlet" + "?" + "account=" + tfAcct.getString() + "&" + "password=" + tfPwd.getString();
        try
            http = (HttpConnection) Connector.open(url);
            // Client Request
            //  1) Send request method
            http.setRequestMethod(HttpConnection.GET);
            //  2) Send header information - none
            //  3) Send boday/data - data is at the end of URL
            //  Server Response
            iStrm = http.openInputStream();
            // Three steps are processed in this method call
            ret = processServerResponse( http, iStrm);
        finally
            // Clean up
            if (iStrm != null)
                iStrm.close();
            if (http != null)
                http.close();
        // Process request failed, show alert
        if (ret == false)
            showAlert(errorMsg);
     * Access servlet using POST
    private void lookupBalance_withPOST() throws IOException
        HttpConnection http = null;
        OutputStream oStrm = null;
        InputStream iStrm = null;
        boolean ret = false;
        // Data is passed at the end of url for GET
        String url = "http://ismt.no-ip.com/servlet/DRMfypGroup2.GetNpostServlet" + "?" + "account=" + tfAcct.getString() + "&" + "password=" + tfPwd.getString();
        try
            http = (HttpConnection) Connector.open(url);
            oStrm = http.openOutputStream();
            // Client Request
            //  1) Send request method
            http.setRequestMethod(HttpConnection.POST);
            //  2) Send header information. Required for POST to work!
            http.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
            // If you experience connectoin/IO problems, try removing the comment from the following line
            //http.serRequestProperty("Connection", "clsoe");
            //  3) Send boday/data
            // Write account number
            byte data[] = ("account=" + tfAcct.getString()).getBytes();
            oStrm.write(data);
            oStrm.flush();
            //  Server Response
            iStrm = http.openInputStream();
            // Three steps are processed in this method call
            ret = processServerResponse(http, iStrm);
        finally
            // Clean up
            if (iStrm != null)
                iStrm.close();
            if (http != null)
                http.close();
        // Process request failed, show alert
        if (ret == false)
            showAlert(errorMsg);
     * Process a response from a server
    private boolean processServerResponse(HttpConnection http, InputStream iStrm) throws IOException
        // Reset  error message
        errorMsg = null;
        //  1) Get Statis Line
        if (http.getResponseCode() == HttpConnection.HTTP_OK)
            //  2) Get header information - none
            //  3) Get body (data)
            int length = (int) http.getLength();
            String str;
           if (length != -1)
               byte servletData[] = new byte[length];
               iStrm.read(servletData);
               str = new String(servletData);
           else  // Length not available...
               ByteArrayOutputStream bStrm = new ByteArrayOutputStream();
               int ch;
               while ( (ch =iStrm.read()) != -1)
                   bStrm.write(ch);
               str = new String (bStrm.toByteArray());
               bStrm.close();
            //Update the string item on the display
            siBalance.setText(str);
            return true;
        else
            // Use message from the servlet
            errorMsg = new String ( http.getResponseMessage() );
        return false;
     * Show an alert
    private void showAlert(String msg)
        // Create Alert, use message returned from servlet
        alError = new Alert("Error", msg, null, AlertType.ERROR);
        // Set Alert to type model
        alError.setTimeout(Alert.FOREVER);
        // Display the Alert. Once dismissed, display the form
        display.setCurrent( alError, fmMain);
}Thanks!!!