Persistent Store problem, need your help! ~

Forgive and I would like to make a short story.

Days, I am according to the A13_Storing_Persistent_Data_V2 document and fantasize for only a class useful for my application, but I am failed completely, here is that the source code written in the document.

import net.rim.device.api.ui.*;
import net.rim.device.api.ui.component.*;
import net.rim.device.api.ui.container.*;
import net.rim.device.api.system.*;
import net.rim.device.api.util.*;
import java.util.*; 

public class MusicStores extends UiApplication { 

  private AutoTextEditField namefield;
  private AutoTextEditField addressfield;
  private EditField phonefield;
  private EditField specialtyfield;
  private static Vector _data;
  private static PersistentObject store; 

  public static void main(String[] args) {
    MusicStores app = new MusicStores();
    app.enterEventDispatcher();
  } 

  public MusicStores() {
    MainScreen mainScreen = new MainScreen();
    mainScreen.setTitle(new LabelField("Favourite Music Store"));
    namefield = new AutoTextEditField("Store Name: ", "");
    addressfield = new AutoTextEditField("Address: ", "");
    phonefield = new EditField("Phone Number: ", "", Integer.MAX_VALUE, BasicEditField.FILTER_PHONE);
    specialtyfield = new EditField("Music Type: ", "", Integer.MAX_VALUE, BasicEditField.FILTER_DEFAULT);
    mainScreen.add(namefield);
    mainScreen.add(addressfield);
    mainScreen.add(phonefield);
    mainScreen.add(specialtyfield);
    mainScreen.addMenuItem(saveItem);
    mainScreen.addMenuItem(getItem);
    pushScreen(mainScreen);
  } 

  private MenuItem saveItem = new MenuItem("Save", 110, 10) {
    public void run() {
      StoreInfo info = new StoreInfo();
      info.setElement(StoreInfo.NAME, namefield.getText());
      info.setElement(StoreInfo.ADDRESS, ddressfield.getText());
      info.setElement(StoreInfo.PHONE, phonefield.getText());
      info.setElement(StoreInfo.SPECIALTY, specialtyfield.getText());
      _data.addElement(info);
      synchronized (store) {
        store.setContents(_data);
        store.commit();
      }
      Dialog.inform("Success!");
      namefield.setText(null);
      addressfield.setText(null);
      phonefield.setText("");
      specialtyfield.setText("");
    }
  }; 

  private MenuItem getItem = new MenuItem("Get", 110, 11) {
    public void run() {
      synchronized (store) {
        _data = (Vector) store.getContents();
        if (!_data.isEmpty()) {
          StoreInfo info = (StoreInfo) _data.lastElement(); 

          namefield.setText(info.getElement(StoreInfo.NAME));
          addressfield.setText(info.getElement(StoreInfo.ADDRESS));
          phonefield.setText(info.getElement(StoreInfo.PHONE));
          specialtyfield.setText(info.getElement(StoreInfo.SPECIALTY));
        }
      }
    }
  }; 

  static {
    store = PersistentStore.getPersistentObject(0xdec6a67096f833cL);
    synchronized (store) {
      if (store.getContents() == null) {
        store.setContents(new Vector());
        store.commit();
      }
    }
    _data = new Vector();
    _data = (Vector) store.getContents();
  } 

  private static final class StoreInfo implements Persistable {
    private Vector _elements;
    public static final int NAME = 0;
    public static final int ADDRESS = 1;
    public static final int PHONE = 2;
    public static final int SPECIALTY = 3; 

    public StoreInfo() {
      _elements = new Vector(4);
      for (int i = 0; i < _elements.capacity(); ++i) {
        _elements.addElement(new String(""));
      }
    } 

    public String getElement(int id) {
      return (String) _elements.elementAt(id);
    } 

    public void setElement(int id, String value) {
      _elements.setElementAt(value, id);
    }
  }
}

I put this code into two parts, the first part to record the second part to get info and the info, and they use the same class of StoreInfo, here is the code of the first part.

import net.rim.device.api.ui.*;
import net.rim.device.api.ui.component.*;
import net.rim.device.api.ui.container.*;
import net.rim.device.api.system.*;
import net.rim.device.api.util.*;
import java.util.*; 

public class SaveMusicInfo extends UiApplication { 

  private AutoTextEditField namefield;
  private AutoTextEditField addressfield;
  private EditField phonefield;
  private EditField specialtyfield;
  private static Vector _data;
  private static PersistentObject store; 

  public static void main(String[] args) {
    SaveMusicInfo app = new SaveMusicInfo();
    app.enterEventDispatcher();
  } 

  public SaveMusicInfo() {
    MainScreen mainScreen = new MainScreen();
    mainScreen.setTitle(new LabelField("Favourite Music Store"));
    namefield = new AutoTextEditField("Store Name: ", "");
    addressfield = new AutoTextEditField("Address: ", "");
    phonefield = new EditField("Phone Number: ", "", Integer.MAX_VALUE, BasicEditField.FILTER_PHONE);
    specialtyfield = new EditField("Music Type: ", "", Integer.MAX_VALUE, BasicEditField.FILTER_DEFAULT);
    mainScreen.add(namefield);
    mainScreen.add(addressfield);
    mainScreen.add(phonefield);
    mainScreen.add(specialtyfield);
    mainScreen.addMenuItem(saveItem);
    mainScreen.addMenuItem(getItem);
    pushScreen(mainScreen);
  } 

  private MenuItem saveItem = new MenuItem("Save", 110, 10) {
    public void run() {
      StoreInfo info = new StoreInfo();
      info.setElement(StoreInfo.NAME, namefield.getText());
      info.setElement(StoreInfo.ADDRESS, ddressfield.getText());
      info.setElement(StoreInfo.PHONE, phonefield.getText());
      info.setElement(StoreInfo.SPECIALTY, specialtyfield.getText());
      _data.addElement(info);
      synchronized (store) {
        store.setContents(_data);
        store.commit();
      }
      Dialog.inform("Success!");
      namefield.setText(null);
      addressfield.setText(null);
      phonefield.setText("");
      specialtyfield.setText("");
    }
  }; 

  static {
    store = PersistentStore.getPersistentObject(0xdec6a67096f833cL);
    synchronized (store) {
      if (store.getContents() == null) {
        store.setContents(new Vector());
        store.commit();
      }
    }
    _data = new Vector();
    _data = (Vector) store.getContents();
  } 

  private static final class StoreInfo implements Persistable {
    private Vector _elements;
    public static final int NAME = 0;
    public static final int ADDRESS = 1;
    public static final int PHONE = 2;
    public static final int SPECIALTY = 3; 

    public StoreInfo() {
      _elements = new Vector(4);
      for (int i = 0; i < _elements.capacity(); ++i) {
        _elements.addElement(new String(""));
      }
    } 

    public String getElement(int id) {
      return (String) _elements.elementAt(id);
    } 

    public void setElement(int id, String value) {
      _elements.setElementAt(value, id);
    }
  }
}

Following is the code of the second part.

import net.rim.device.api.ui.*;
import net.rim.device.api.ui.component.*;
import net.rim.device.api.ui.container.*;
import net.rim.device.api.system.*;
import net.rim.device.api.util.*;
import java.util.*; 

public class GetMusicInfo extends UiApplication { 

  private AutoTextEditField namefield;
  private AutoTextEditField addressfield;
  private EditField phonefield;
  private EditField specialtyfield;
  private static Vector _data;
  private static PersistentObject store; 

  public static void main(String[] args) {
    GetMusicInfo app = new GetMusicinfo();
    app.enterEventDispatcher();
  } 

  public GetMusicInfo() {
    MainScreen mainScreen = new MainScreen();
    mainScreen.setTitle(new LabelField("Favourite Music Store"));
    namefield = new AutoTextEditField("Store Name: ", "");
    addressfield = new AutoTextEditField("Address: ", "");
    phonefield = new EditField("Phone Number: ", "", Integer.MAX_VALUE, BasicEditField.FILTER_PHONE);
    specialtyfield = new EditField("Music Type: ", "", Integer.MAX_VALUE, BasicEditField.FILTER_DEFAULT);
    mainScreen.add(namefield);
    mainScreen.add(addressfield);
    mainScreen.add(phonefield);
    mainScreen.add(specialtyfield);
    mainScreen.addMenuItem(saveItem);
    mainScreen.addMenuItem(getItem);
    pushScreen(mainScreen);
  } 

  private MenuItem getItem = new MenuItem("Get", 110, 11) {
    public void run() {
      synchronized (store) {
        _data = (Vector) store.getContents();
        if (!_data.isEmpty()) {
          StoreInfo info = (StoreInfo) _data.lastElement(); 

          namefield.setText(info.getElement(StoreInfo.NAME));
          addressfield.setText(info.getElement(StoreInfo.ADDRESS));
          phonefield.setText(info.getElement(StoreInfo.PHONE));
          specialtyfield.setText(info.getElement(StoreInfo.SPECIALTY));
        }
      }
    }
  }; 

  static {
    store = PersistentStore.getPersistentObject(0xdec6a67096f833cL);
    synchronized (store) {
      if (store.getContents() == null) {
        store.setContents(new Vector());
        store.commit();
      }
    }
    _data = new Vector();
    _data = (Vector) store.getContents();
  } 

  private static final class StoreInfo implements Persistable {
    private Vector _elements;
    public static final int NAME = 0;
    public static final int ADDRESS = 1;
    public static final int PHONE = 2;
    public static final int SPECIALTY = 3; 

    public StoreInfo() {
      _elements = new Vector(4);
      for (int i = 0; i < _elements.capacity(); ++i) {
        _elements.addElement(new String(""));
      }
    } 

    public String getElement(int id) {
      return (String) _elements.elementAt(id);
    } 

    public void setElement(int id, String value) {
      _elements.setElementAt(value, id);
    }
  }
}

I'm runing the Project One (first part) and record information to be stored, and then I WANT TO runing the project two (part two), but I received an error message telling me there are two same defined the class in the system, I try to change the class name of StoreInfo in two project, the last of error messge disappeared , instead of a CastClassException error, I am so sad...

For a long time debugging I found some interesting things, look at the below codes to two projects, please read the name of the StoreInfor class, not StoreInfo.

 private MenuItem getItem = new MenuItem("Get", 110, 11) {
    public void run() {
      synchronized (store) {
        _data = (Vector) store.getContents();
        if (!_data.isEmpty()) {
          StoreInfor info = (StoreInfor) _data.lastElement();
        }
      }
    }
  };

Now the _data class name is StoreInfo@xxxxxx (using _data.getClass () .getName ()) and class StoreInfo project two was renamed to StoreInfor, of course, I received a CastClassException error.

I finished the story, and I need some guys to help solve this problem, tks a lot! ~