1 Reply Latest reply: Apr 21, 2011 2:45 AM by Anshul RSS

    Java ME, Input Validation

    845988
      I am fairly new to Java ME and I am having some trouble, I have an application that allows you to rate food establishment, however I am trying to add some validation so that if the user leaves a field blank, when they try to submit the details they have entered it will stop them from continuing and make them go back. Here is the code I have so far would anyone please be able to help me?


      package hello;

      import javax.microedition.midlet.*;import javax.microedition.midlet.*;
      import javax.microedition.lcdui.*;
      import java.io.*;
      import javax.microedition.io.*;


      public class Rater extends MIDlet implements CommandListener
      {
      private Display mDisplay;
      private Alert mAlert;
      private Form mForm;
      private ChoiceGroup chcEstablishmentType;
      private TextField ID, txtPlaceName, txtLocation, txtRating, txtFoodsold;
      private String strPlace, strLocation, strID, strRating, strFoodsold, strEstablishmentType;

      public Rater()
      {
      String [] EstablishmentType = {"Bar", "Restaurant ", "Cafe'"};
      mForm = new Form("Enter your order details");
      ID = new TextField("ID*: ", null, 4, TextField.ANY);
      chcEstablishmentType = new ChoiceGroup("Type of Establishment*", Choice.EXCLUSIVE, EstablishmentType, null);
      txtFoodsold = new TextField("Food Sold*", null, 20, TextField.ANY);
      txtPlaceName = new TextField("Establishment Name*:", null, 15, TextField.ANY);
      txtLocation = new TextField("Location*:", null, 15, TextField.ANY);
      txtRating = new TextField("Rating*:", null, 5, TextField.ANY);
      mForm.append(ID);
      mForm.append(txtPlaceName);
      mForm.append(txtLocation);
      mForm.append(txtFoodsold);
      mForm.append(txtRating);
      mForm.append(chcEstablishmentType);
      mForm.addCommand(new Command("Exit", Command.EXIT, 0));
      mForm.addCommand(new Command("Next", Command.SCREEN, 0));
      mForm.setCommandListener(this);
      mAlert = new Alert("Your order", "", null, AlertType.CONFIRMATION);
      mAlert.addCommand(new Command("Back", Command.BACK, 0));
      mAlert.addCommand(new Command("Confirm", Command.OK,1));
      mAlert.setTimeout(Alert.FOREVER);
      }

      protected void startApp()
      {
      mDisplay = Display.getDisplay(this);
      mDisplay.setCurrent(mForm);
      }


      public void commandAction(Command c, Displayable d)
      {
      if (c.getLabel().equals("Exit"))
      {
      notifyDestroyed();
      }
      if (c.getLabel().equals("Next"))
      {
      strID = ID.getString();
      strPlace = txtPlaceName.getString();
      strLocation = txtLocation.getString();
      strRating = txtRating.getString();
      strFoodsold = txtFoodsold.getString();


      strEstablishmentType = chcEstablishmentType.getString(chcEstablishmentType.getSelectedIndex());
      String strOrderDetails = "ID: " + strID + "ordered " + strFoodsold + " from a \n " + strEstablishmentType + " called " + strPlace + "\n in " + strLocation
      + "\n rating it with " + strRating + " stars ";
      mAlert.setString(strOrderDetails);
      mDisplay.setCurrent(mAlert);
      }

      }

      protected void destroyApp(boolean param) {}
      protected void pauseApp() {}
      }
        • 1. Re: Java ME, Input Validation
          Anshul
          hey try this code:-

          import javax.microedition.lcdui.;*
          import javax.microedition.midlet.MIDlet;
          public class Rater extends MIDlet implements CommandListener
          *{*
          private Display mDisplay;
          private Alert mAlert;
          private Form mForm;
          private ChoiceGroup chcEstablishmentType;
          private TextField ID, txtPlaceName, txtLocation, txtRating, txtFoodsold;
          private String strPlace, strLocation, strID, strRating, strFoodsold, strEstablishmentType;
          private Alert error_alert;

          public Rater()
          *{*
          String [] EstablishmentType = {"Bar", "Restaurant ", "Cafe'"};
          mForm = new Form("Enter your order details");
          ID = new TextField("ID: ", null, 4, TextField.ANY);*
          *chcEstablishmentType = new ChoiceGroup("Type of Establishment*", Choice.EXCLUSIVE, EstablishmentType, null);*
          *txtFoodsold = new TextField("Food Sold*", null, 20, TextField.ANY);*
          *txtPlaceName = new TextField("Establishment Name*:", null, 15, TextField.ANY);*
          *txtLocation = new TextField("Location*:", null, 15, TextField.ANY);*
          *txtRating = new TextField("Rating*:", null, 5, TextField.ANY);*
          *mForm.append(ID);*
          *mForm.append(txtPlaceName);*
          *mForm.append(txtLocation);*
          *mForm.append(txtFoodsold);*
          *mForm.append(txtRating);*
          *mForm.append(chcEstablishmentType);*
          *mForm.addCommand(new Command("Exit", Command.EXIT, 0));*
          *mForm.addCommand(new Command("Next", Command.SCREEN, 0));*
          *mForm.setCommandListener(this);*
          *mAlert = new Alert("Your order", "", null, AlertType.CONFIRMATION);*
          *mAlert.addCommand(new Command("Back", Command.BACK, 0));*
          *mAlert.addCommand(new Command("Confirm", Command.OK,1));*
          *mAlert.setTimeout(Alert.FOREVER);*
          *error_alert = new Alert("error","",null,AlertType.ERROR);*
          *error_alert.setTimeout(500);*
          *}*

          *protected void startApp()*
          *{*
          *mDisplay = Display.getDisplay(this);*
          *mDisplay.setCurrent(mForm);*
          *}*
          *public void commandAction(Command c, Displayable d)*
          *{*
          *if (c.getLabel().equals("Exit"))*
          *{*
          *notifyDestroyed();*
          *}*
          *if (c.getLabel().equals("Next"))*
          *{*
          *strID = ID.getString();*
          *strPlace = txtPlaceName.getString();*
          *strLocation = txtLocation.getString();*
          *strRating = txtRating.getString();*
          *strFoodsold = txtFoodsold.getString();*
          *strEstablishmentType = chcEstablishmentType.getString(chcEstablishmentType.getSelectedIndex());*

          *if(strID.equals(""))*
          *{*
          *String s = "enter ID";*
          *error_alert.setString(s);*
          *mDisplay.setCurrent((Displayable) error_alert);*
          *}*
          *if(strPlace.equals(""))*
          *{*
          *String s = "enter establishment name";*
          *error_alert.setString(s);*
          *mDisplay.setCurrent((Displayable) error_alert);*
          *}*

          *else if(strLocation.equals(""))*
          *{*
          *String s = "enter Location";*
          *error_alert.setString(s);*
          *mDisplay.setCurrent((Displayable) error_alert);*
          *}*

          *else if (strRating.equals(""))*
          *{*
          *String s = "enter rating";*
          *error_alert.setString(s);*
          *mDisplay.setCurrent((Displayable) error_alert);*
          *}*

          *else if(strFoodsold.equals(""))*
          *{*
          *String s = "enter the name of food sold";*
          *error_alert.setString(s);*
          *mDisplay.setCurrent((Displayable) error_alert);*
          *}*

          *else if(strEstablishmentType.equals(""))*
          *{*
          *String s = "enter type of establishment";*
          *error_alert.setString(s);*
          *mDisplay.setCurrent((Displayable) error_alert);*
          *}*


          *else*
          *{*
          *String strOrderDetails = "ID: " + strID + "ordered " + strFoodsold + " from a \n " + strEstablishmentType + " called " + strPlace + "\n in " + strLocation*
          *+ "\n rating it with " + strRating + " stars ";*
          *mAlert.setString(strOrderDetails);*
          *mDisplay.setCurrent(mAlert);*
          *}*
          *}*

          *}*

          *protected void destroyApp(boolean param) {}*
          *protected void pauseApp() {}*
          *}*