Not getting value in midlet from servlet

[Kenneth Owino]

Hi friends. I'm trying to send data from a midlet to a servlet and recieve back a response from the servlet but I

don't get any value in response. I've tried to print it on command window and it seems to be null yet I expect only

two values "ok" or "error". Please help me check the code and let me know what I should do to get the response right

on the midlet. My code is below:

import javax.microedition.midlet.*;//midlet class package import
import javax.microedition.lcdui.*;//package for ui and commands
import javax.microedition.io.*;//
import java.io.*;

/**
 * @author k'owino
 */
//Defining the midlet class
public class MvsMidlet extends MIDlet implements CommandListener {

    private boolean midletPaused = false;//variable for paused state of midlet
    //defining variables
    private Display display;// Reference to Display object
    private Form welForm;
    private Form vCode;//vote code
    private StringItem welStr;
    private TextField phoneField;
    private StringItem phoneError;
    private Command quitCmd;
    private Command contCmd;

    //constructor of the midlet
    public MvsMidlet() {

        display = Display.getDisplay(this);//creating the display object
        welForm = new Form("THE MVS");//instantiating welForm object
        welStr = new StringItem("", "Welcome to the MVS, Busitema's mobile voter."
                + "Please enter the your phone number below");//instantiating welStr string item
        phoneError = new StringItem("", "");//intantiating phone error string item
        phoneField = new TextField("Phone number e.g 0789834141", "", 10, 3);//phone number field object
        quitCmd = new Command("Quit", Command.EXIT, 0);//creating quit command object
        contCmd = new Command("Continue", Command.OK, 0);//creating continue command object
        welForm.append(welStr);//adding welcome string item to form
        welForm.append(phoneField);//adding phone field to form
        welForm.append(phoneError);//adding phone error string item to form
        welForm.addCommand(contCmd);//adding continue command
        welForm.addCommand(quitCmd);//adding quit command
        welForm.setCommandListener(this);
        display.setCurrent(welForm);

    }

    //start application method definition
    public void startApp() {
    }

    //pause application method definition
    public void pauseApp() {
    }

    //destroy application method definition
    public void destroyApp(boolean unconditional) {
    }

    //Command action method definition
    public void commandAction(Command c, Displayable d) {
        if (d == welForm) {
            if (c == quitCmd) {
                exitMidlet();//call to exit midlet
            } else {//if the command is contCmd
                //place a waiting activity indicator
                System.out.println("ken de man");
                Thread t = new Thread() {

                    public void run() {
                        try {

                            //method to connect to server
                            sendPhone();

                        } catch (Exception e) {
                        }//end of catch
                    }//end of ru()
                };//end of thread
                t.start();//starting the thread
            }//end of else
        }//end of first if

    }//end of command action

    //defining method to exit midlet
    public void exitMidlet() {
        display.setCurrent(null);
        destroyApp(true);
        notifyDestroyed();
    }//end of exitMidlet()

    //defining sendPhone method
    public void sendPhone() throws IOException {

        System.out.println("ken de man");//check

        HttpConnection http = null;//HttpConnection variable
        OutputStream oStrm = null;//OutputStream variable
        InputStream iStrm = null;//InputStream variable
        String url = "http://localhost:8084/MvsWeb/CheckPhone";//server url

        try {
            http = (HttpConnection) Connector.open(url);//opening connection
            System.out.println("connection made");//checking code
            oStrm = http.openOutputStream();//opening output stream
            http.setRequestMethod(HttpConnection.POST);//setting request type
            http.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");//setting content type
            byte data[] = ("phone=" + phoneField.getString()).getBytes();
            oStrm.write(data);
            iStrm = http.openInputStream();//openning input stream
            if (http.getResponseCode() == HttpConnection.HTTP_OK) {
                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();
                }
                System.out.println("de man");

                System.out.println(str);

                if (str.equals("ok")) {
                    //change to vcode form

                } else {
                    //add error message to phone_error stingItem
                }
            }
        } catch (Exception e) {
        }
    }
}//end of class definition


//servlet
import java.io.*;//package for io classes
import javax.servlet.ServletException;//package for servlet exception classes
import javax.servlet.http.*;
import java.sql.*;//package for sql classes

/**
 *
 * @author k'owino
 */
public class CheckPhone extends HttpServlet {
   
    @Override
    protected void doGet(HttpServletRequest req, HttpServletResponse res)
    throws ServletException, IOException {

    } 


    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse res)
    throws ServletException, IOException {

        //declaring variables
        PrintWriter pw;//PrintWriter object
        String pnum;//phone parameter sent from client
        Connection con = null;//connection variable
        String dbDriver = "com.jdbc.mysql.Driver";//the database driver
        String dbUrl = "jdbc:mysql://localhost/mvs_db";//the database url
        String dbUser = "root";//database user
        String dbPwd = "";//database password
        PreparedStatement pstmt = null;//Prepared statement variable
        String query = "select * from student where stud_phone = ?;";
        ResultSet rs = null;//resultset variable
        String dbPhone=null;//phone from database

        //getting the "phone" parameter sent from client
        pnum = req.getParameter("phone");//getting the "phone" parameter sent from client
        System.out.println(pnum);

        //setting the content type of the response
        res.setContentType("text/html");

        //creating a PrintWriter object
        pw = res.getWriter();
        pw.println("ken");

        try{//trying to load the database driver and establish a connection to the database

            Class.forName(dbDriver).newInstance();//loading the database driver
            con = DriverManager.getConnection(dbUrl,dbUser,dbPwd);//establishing a connection to the database
            System.out.println("connection established");
        }
        catch(Exception e){

        }

        //trying to query the database
        try{

            pstmt = con.prepareStatement(query);//preparing a statement
            pstmt.setString(1, pnum);//setting the input parameter
            rs = pstmt.executeQuery();//executing the query assigning to the resultset object

            //extracring data from the resultset
            while(rs.next()){
                dbPhone = rs.getString("stud_phone");//getting the phone number from database
            }//end of while

            if(pnum.equals(dbPhone)){
                pw.print("ok");
                pw.close();
            }
            else{
                pw.print("error");
                pw.close();
            }

        }
        catch(Exception e){

        }
        
    }


    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>

}

[Maneesh Godbole]

catch(Exception e){

}

If I were you, I would start by changing it to

catch(Exception e){
e.printStackTrace();
}

[Soumya Rout]

Try this

http = (HttpConnection) Connector.open(url+"?phone="+phoneField.getString();