How to write data to a file in Java ME

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

public class WriteMIDlet extends MIDlet implements CommandListener {

   private TextBox textbox;
   private String photos = "fileconn.dir.photos";
   private Command saveCommand;
   private Command exitCommand;
   private String path;

   public void startApp() {
       textbox = new TextBox("WriteMIDlet", "", 1000, TextField.ANY);
       saveCommand = new Command("Save", Command.SCREEN, 1);
       exitCommand = new Command("Exit", Command.EXIT, 1);
       textbox.addCommand(saveCommand);
       textbox.addCommand(exitCommand);
       textbox.setCommandListener(this);
       Display.getDisplay(this).setCurrent(textbox);
       path = System.getProperty(photos);
   }

   public void pauseApp() {
   }

   public void destroyApp(boolean unconditional) {
   }

   private void saveFile(String path, String name) {
       try {
           //String url = path + name;
            String url=""file:///SDCard/A.TXT"";
           String string = textbox.getString();
           byte data[] = string.getBytes();
           FileConnection fconn = (FileConnection)Connector.open(url, Connector.READ_WRITE);
           if (!fconn.exists()) {
               fconn.create();
           }
           OutputStream ops = fconn.openOutputStream();
           ops.write(data);
           ops.close();
           fconn.close();
       }
       catch (IOException ioe) {
           System.out.println("IOException: "+ioe.getMessage());
       }
       catch (SecurityException se) {
           System.out.println("Security exception:" + se.getMessage());
       }
   } 

   public void commandAction(Command c, Displayable d) {
       if (c == saveCommand) saveFile(path, "readme.txt");
       if (c == exitCommand) this.notifyDestroyed();
   }    

}

the above code throwing an ioexception if i run it in 3100c nokia.. please help me..

Cedsadbe - Change path

Change the url path using "fileconn.dir.memorycard" in photos String.

cedsadbe 00:24, 17 November 2011 (EET)

Hamishwillee - Cedsadbe - does this need to be changed in the article itself?

If so, could you please update it?

hamishwillee 05:11, 29 November 2011 (EET)

AnorEnaj2330 - Where can i find that textfile

Good day!

so i try it to my j2me but it's not working where can i create a textfile . or its automatically created? you created it first in a folder or when you written those codes it's automatic created.?

tnx

AnorEnaj2330 05:14, 21 September 2012 (EEST)

Hamishwillee - @AnorEnaj2330 try the forums

Hi AnorEnaj2330

This was written 3 years ago, so the author may not be watching this article. I suggest you raise the issue in the Java Discussion board, linking to this article.

Regards

Hamish

hamishwillee 08:30, 21 September 2012 (EEST)

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This article shows, how to write data to a file by using FileConnection API (JSR-75). This example MIDlet has a TextBox, where text can be entered. Then the text can be saved to readme.txt file, which is in this case created under Gallery's Images folder.

Article Metadata

---

Code Example

Source file: WriteDataExample sources

Installation file: WriteDataExample binaries

---

Tested with

SDK: Nokia Asha SDK 1.0 (beta), Nokia SDK 1.1 for Java, Nokia SDK 2.0 for Java (beta), Nokia Symbian SDKs

Devices(s): Nokia Asha 501, Nokia C3-01, Nokia Asha 306, Nokia E7-00

---

Compatibility

Platform(s): Nokia Asha Platform 1.0 and later, Series 40 DP 1.0 and later, Nokia Belle

---

Article

Keywords: textBox,Commndbutton,String,FileConnection

Created: jarmlaht (28 Jan 2009)

Reviewed: skalogir (09 May 2013)

Last edited: skalogir (13 May 2013)

Source code: WriteMIDlet.java

The full source code for a test MIDlet:

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import javax.microedition.io.file.*;
import javax.microedition.io.*;
import java.io.*;
 
public class WriteMIDlet extends MIDlet implements CommandListener {
    private TextBox textbox;
    private String photos = "fileconn.dir.photos";
    private Command saveCommand;
    private Command exitCommand;
    private String path;
 
    public void startApp() {
        textbox = new TextBox("WriteMIDlet", "", 1000, TextField.ANY);
        saveCommand = new Command("Save", Command.SCREEN, 1);
        exitCommand = new Command("Exit", Command.EXIT, 1);
        textbox.addCommand(saveCommand);
        textbox.addCommand(exitCommand);
        textbox.setCommandListener(this);
        Display.getDisplay(this).setCurrent(textbox);
        path = System.getProperty(photos);
    }
 
    public void pauseApp() {
    }
 
    public void destroyApp(boolean unconditional) {
    }
 
    private void saveFile(String path, String name) {
        try {
            String url = path + name;
            String string = textbox.getString();
            byte data[] = string.getBytes("UTF-8");
            FileConnection fconn = (FileConnection)Connector.open(url, Connector.READ_WRITE);
            if (!fconn.exists()) {
                fconn.create();
            }
            OutputStream ops = fconn.openOutputStream();
            ops.write(data);
            ops.close();
            fconn.close();
        }
        catch (IOException ioe) {
            System.out.println("IOException: "+ioe.getMessage());
        }
        catch (SecurityException se) {
            System.out.println("Security exception:" + se.getMessage());
        }
    } 
 
    public void commandAction(Command c, Displayable d) {
        if (c == saveCommand) saveFile(path, "readme.txt");
        if (c == exitCommand) this.notifyDestroyed();
    }    
}

See also

• How to list root file systems in Java ME
• How to list files and folders in Java ME
• How to read an image from Gallery in Java ME