Record store does not work on mobile phone

[shv_rk]

Hello all,

I am developing an application for mobile phone with J2ME(CDLC, MIDP 2.0 ) for Nokia S60 using netbeans 6.5 IDE. I am recording a data using record store and then reading it. it is working fine in emulator. However, I install it on my mobile phone it saves data but unfortunately when I close application and then open it data does not exist anymore.
any idea? Do I need to do any settings in my mobile phone or netbeans? my phone is Nokia e71.
here is my code:
public boolean save() {
RecordStore rs = null;
try {
rs = RecordStore.openRecordStore("myNotes", true);


} catch (RecordStoreException rse) {
System.err.println(rse.toString());
return false;
}
byte[] elementToBeSaved = this.toByte();

try {
rs.addRecord(elementToBeSaved, 0, elementToBeSaved.length);


} catch (RecordStoreException ex) {
ex.printStackTrace();
return false;
}
return true;
}

elementToBeSaved is a Vector which then convert it to byte.

here I read from store:
public static Vector getMynotes() {
Vector records = new Vector();
Vector result = new Vector();
RecordStore rs = null;
try {
rs = RecordStore.openRecordStore("myNotes", true);


} catch (RecordStoreException rse) {
System.err.println(rse.toString());
return null;
}
try {
for (int i = 1; i <= rs.getNumRecords(); i++) {
// Get data into the byte array
byte[] recordAsByte = rs.getRecord(i);
records.addElement(new String(recordAsByte));
}

for (int i = 0 ; i<records.size() ; i++){

}

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

for (int i = 0; i < records.size(); i++) {
String record = (String) records.elementAt(i);
result.addElement(getMynotes(record));
}
return result;

}



Thanks

[grahamhughes]

From the code you post, you are not closing the record store. You must close the record store, or data will be lost. You need to ensure that record stores are closed in all situations, even if exceptions are thrown.

For example:

public static Vector getMynotes() throws RecordStoreException {
    Vector result = new Vector();
    RecordStore rs = openRecordStore("myNotes", true);
    try {
        int num = rs.getNumRecords();
        for (int i = 1; i <= num; i++) {
            byte[] data = rs.getRecord(i);
            result.addElement(getMyNoted(data));
        }
    } finally {
        rs.closeRecordStore();
    }
    return result;
} 

Note that this version adds a closeRecordStore(), and this is in a finally{} block, which ensures that the close will always happen.

Also, there is no catch{} block. Any exception will be passed back to the caller. This is much more useful than returning "null" or an incomplete result vector, since the exception contains information about what went wrong.

Graham.

[shv_rk]

Dear Graham,

I changed my code.However I did not work again

public boolean save() throws RecordStoreException {
RecordStore rs = null;
try {
rs = RecordStore.openRecordStore("myNotes", true);


} catch (RecordStoreException rse) {
System.err.println(rse.toString());
return false;
}
byte[] elementToBeSaved = this.toByte();

try {
rs.addRecord(elementToBeSaved, 0, elementToBeSaved.length);

} finally {
rs.closeRecordStore();
}

return true;
}

public static Vector getStoredShoppingLists() throws RecordStoreException {
Vector records = new Vector();
Vector result = new Vector();
RecordStore rs = null;
rs = RecordStore.openRecordStore("myNotes", true);
try {
int num = rs.getNumRecords();
for (int i = 1; i <= num; i++) {
byte[] recordAsByte = rs.getRecord(i);
records.addElement(new String(recordAsByte));
}

} finally {
rs.closeRecordStore();
}

for (int i = 0; i < records.size(); i++) {
String record = (String) records.elementAt(i);
result.addElement(getMyNotes(record));
}
return result;
}
Please help!!

Thanks

[grahamhughes]

Try this:

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

public class Rms extends MIDlet implements CommandListener {
    private static final String RS_NAME = "test";
    private static final String ENCODING = "UTF-8";
    private static final Command CMD_SAVE = new Command("Save", Command.SCREEN, 1);
    private static final Command CMD_EXIT = new Command("Exit", Command.EXIT, 1);

    private TextBox text;
    
    public void startApp() {
        String message = null;
        if (text == null) {
            String s;
            try {
                s = read();
            } catch (Exception e) {
                s = "(error)";
                message = e.toString();
            }
            text = new TextBox("Test", s, 256, TextField.ANY);
            text.addCommand(CMD_SAVE);
            text.addCommand(CMD_EXIT);
            text.setCommandListener(this);
        }
        Display display = Display.getDisplay(this);
        if (message == null) {
            display.setCurrent(text);
        } else {
            Alert alert = new Alert("Rms", message, null, AlertType.ERROR);
            display.setCurrent(alert, text);
        }
    }
    
    public void destroyApp(boolean b){}
    
    public void pauseApp(){}

    public void commandAction(Command c, Displayable d) {
        if (c == CMD_SAVE) {
            String message;
            AlertType type;
            try {
                write(text.getString());
                message = "Saved.";
                type = AlertType.CONFIRMATION;
            } catch (Exception e) {
                message = e.toString();
                type = AlertType.ERROR;
            }
            Alert alert = new Alert("Rms", message, null, type);
            Display.getDisplay(this).setCurrent(alert);
        } else if (c == CMD_EXIT) {
            notifyDestroyed();
        }
    }

    private static String read() throws RecordStoreException, UnsupportedEncodingException {
        String s;
        RecordStore rs = RecordStore.openRecordStore(RS_NAME, true);
        try {
            if (rs.getNumRecords() > 0) {
                byte[] data = rs.getRecord(1);
                s = new String(data, ENCODING);
            } else {
                s = "(no data)";
            }
        } finally {
            rs.closeRecordStore();
        }
        return s;
    }

    private static void write(String s) throws RecordStoreException, UnsupportedEncodingException {
        byte[] data = s.getBytes(ENCODING);
        RecordStore rs = RecordStore.openRecordStore(RS_NAME, true);
        try {
            if (rs.getNumRecords() == 0) {
                rs.addRecord(data, 0, data.length);
            } else {
                rs.setRecord(1, data, 0, data.length);
            }
        } finally {
            rs.closeRecordStore();
        }
    }
} 

Graham.

[manjul_saini]

hi, it is because you are deleting rs before you exit some where in your code. else its works fine.

[jitu_goldie]

Dear Graham,

I changed my code.However I did not work again

public boolean save() throws RecordStoreException {
RecordStore rs = null;
try {
rs = RecordStore.openRecordStore("myNotes", true);


} catch (RecordStoreException rse) {
System.err.println(rse.toString());
return false;
}
byte[] elementToBeSaved = this.toByte();

try {
rs.addRecord(elementToBeSaved, 0, elementToBeSaved.length);

} finally {
rs.closeRecordStore();
}

return true;
}

public static Vector getStoredShoppingLists() throws RecordStoreException {
Vector records = new Vector();
Vector result = new Vector();
RecordStore rs = null;
rs = RecordStore.openRecordStore("myNotes", true);
try {
int num = rs.getNumRecords();
for (int i = 1; i <= num; i++) {
byte[] recordAsByte = rs.getRecord(i);
records.addElement(new String(recordAsByte));
}

} finally {
rs.closeRecordStore();
}

for (int i = 0; i < records.size(); i++) {
String record = (String) records.elementAt(i);
result.addElement(getMyNotes(record));
}
return result;
}
Please help!!

Thanks

Have u got any exception. If yes then please mention it. As Graham already suggested u that close the recordstore well after taking use of it as early as possible to make ur data consistent and durable. Also as manjul said check that have u delete the recordstore somewhere.

Also please mention the meaning of bold lines. Have u take use of some stream. what u want and what u follow is quite ambiguous. Please mention in detail.