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How to write data to a file in Java ME

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[[Category:Java ME]][[Category:How To]][[Category:Code Examples]][[Category:Files/Data]][[Category:File Connection and PIM API (JSR-75)]]
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[[Category:Java ME]][[Category:How To]][[Category:Code Examples]][[Category:Files/Data]][[Category:File Connection and PIM API (JSR-75)]][[Category:Series 40]][[Category:Symbian]][[Category:S60 3rd Edition FP1]][[Category:S60 3rd Edition FP2]][[Category:S60 5th Edition]][[Category:Series 40 6th Edition FP1]][[Category:Series 40 Developer Platform 2.0]][[Category:Nokia Belle]]
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{{Abstract|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.}}
 
{{ArticleMetaData
 
{{ArticleMetaData
|id=...
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|devices= Nokia C3-01, Nokia Asha 306, Nokia E7-00
|platform=S60 3rd Edition FP1, S60 3rd Edition FP2, S60 5th Edition
+
|platform= Series 40, S60, Nokia Belle
|devices= Emulator
+
|creationdate=20090128
|category=J2ME
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|subcategory=
+
|creationdate=28 January 2009
+
 
|keywords=textBox,Commndbutton,String,FileConnection
 
|keywords=textBox,Commndbutton,String,FileConnection
 
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|sourcecode=[[Media:WriteDataExample_src.zip | WriteDataExample sources]]
|sourcecode= <!-- Link to example source code (e.g. [[Media:The Code Example ZIP.zip]]) -->
+
|installfile= [[Media:WriteDataExample_bin.zip | WriteDataExample binaries]]
|installfile= <!-- Link to installation file (e.g. [[Media:The Installation File.sis]]) -->
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|sdk= [http://www.developer.nokia.com/Develop/Java/ Nokia SDK 1.1 for Java], [http://www.developer.nokia.com/Develop/Java/ Nokia SDK 2.0 for Java (beta)], [http://www.developer.nokia.com/info/sw.nokia.com/id/ec866fab-4b76-49f6-b5a5-af0631419e9c/S60_All_in_One_SDKs.html/ Nokia Symbian SDKs]
|sdk=<!-- SDK(s) built and tested against (e.g. [http://linktosdkdownload/ Nokia Qt SDK 1.1]) -->
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|devicecompatability=<!-- Compatible devices (e.g.: All* (must have GPS) ) -->
 
|devicecompatability=<!-- Compatible devices (e.g.: All* (must have GPS) ) -->
 
|signing=<!-- Empty or one of Self-Signed, DevCert, Manufacturer -->
 
|signing=<!-- Empty or one of Self-Signed, DevCert, Manufacturer -->
|capabilities=<!-- Capabilities required (e.g. Location, NetworkServices. -->)
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|capabilities=<!-- Capabilities required (e.g. Location, NetworkServices.) -->
 
|author=[[User:Jarmlaht]]
 
|author=[[User:Jarmlaht]]
 
}}
 
}}
==Overview==
 
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.
 
 
  
 +
==Source code: WriteMIDlet.java==
 
The full source code for a test MIDlet:
 
The full source code for a test MIDlet:
 
==Source code: WriteMIDlet.java==
 
 
 
<code java>
 
<code java>
 
import javax.microedition.midlet.*;
 
import javax.microedition.midlet.*;
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* [[How to list files and folders in Java ME]]
 
* [[How to list files and folders in Java ME]]
 
* [[How to read an image from Gallery in Java ME]]
 
* [[How to read an image from Gallery in Java ME]]
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<!-- Translation --> [[pt:Como gravar dados em um arquivo em Java ME]]

Revision as of 08:28, 18 September 2012

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
Installation file: WriteDataExample binaries
Tested with
Devices(s): Nokia C3-01, Nokia Asha 306, Nokia E7-00
CompatibilityArticle
Keywords: textBox,Commndbutton,String,FileConnection
Created: jarmlaht (28 Jan 2009)
Last edited: hamishwillee (18 Sep 2012)

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();
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

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