Revision as of 17:38, 19 February 2009 by olkazmin (Talk | contribs)

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)

Changing Bluetooth discoverability in Java ME

From Nokia Developer Wiki
Jump to: navigation, search


Article Metadata
Tested with
Devices(s): Nokia N78, Nokia 5800 XM, Nokia 6131
Keywords: javax.bluetooth.BluetoothStateException, javax.bluetooth.DiscoveryAgent, javax.bluetooth.LocalDevice
Created: (31 Jan 2009)
Last edited: olkazmin (19 Feb 2009)


The folowing code snippet demonstrates how to change discoverability using Bluetooth API.

Discoverability mode can be set using LocalDevice.setDiscoverable method. This method takes discoverability Id as a parameter. This parameter must hold one of the folowing values:


More information on discoverability modes can be found in JSR-82 specification.


In order to test this snippet there should be at least one event in the database. Application needs permission to read and write PIM database data.

Source file: DeleteEvent.java

* Allows to select discoer mode from Bluetooth device.

private List listModes;
* Discoverability mode id array.

private int[] modeArray;
* Instantiates a listModes.

private void setupModeList() {
listModes = new List( "Mode list", Choice.IMPLICIT );
listModes.setSelectCommand( CHANGE_COMMAND );
listModes.addCommand( BACK_COMMAND );
listModes.setCommandListener( this );
// adding discoverability modes to the list
listModes.append( "GIAC", null );
listModes.append( "LIAC", null );
listModes.append( "NOT DISCOVERABLE", null );
//setting mode id array values
modeArray[0] = DiscoveryAgent.GIAC;
modeArray[1] = DiscoveryAgent.LIAC;
modeArray[2] = DiscoveryAgent.NOT_DISCOVERABLE;
* From CommandListener.
* Called by the system to indicate that a command has been invoked on a
* particular displayable.
* @param command the command that was invoked
* @param displayable the displayable where the command was invoked

public void commandAction(Command command, Displayable displayable) {
if (command == EXIT_COMMAND) {
// Exit the MIDlet
} else if (command == EXECUTE_COMMAND) {
// Open discoverability mode list
display.setCurrent( listModes );
} else if ( command == CHANGE_COMMAND ) {
//get currently selected contact
int i = listModes.getSelectedIndex();
String item = listModes.getString( i );
printString( "Selected mode: " + item );
// Bringing back main form to the foreground
display.setCurrent( mainForm );
// Changing discoverability mode
changeMode( i );
} else if ( command == BACK_COMMAND ) {
display.setCurrent( mainForm );
* @param modeIndex

private void changeMode( int modeIndex ) {
LocalDevice devLocal = null;
try {
printString( "Getting local device ..." );
devLocal = LocalDevice.getLocalDevice();
} catch ( BluetoothStateException e ) {
printString( e.toString() );
try {
printString( "Chaning discoverability mode" );
devLocal.setDiscoverable( modeArray[ modeIndex ] );
} catch ( BluetoothStateException e ) {
printString( e.toString() );
printString( "Discoverability mode changed." );


When the MIDlet is started the main form with text field will be displayed. To change current bluetooth device mode you should press 'Modes' softkey, then a list of available modes will be displayed.

When the list appeared select a specific mode from the list and press 'Change' softkey. Main form will be brought to the foreground. If discoverability mode changing procedure succeeded, a Discoverability mode changed' mesage will appear.

Supplementary material

  • You can test the changing of Bluetooth discoverability in action in a simple, executable application into which this code snippet has been patched. The executables and source files are available for download at: linl_to_sources_and_executable.
  • You can examine all the changes that are required to implement the above mentioned features in an application. The changes are provided in unified diff and color-coded diff formats: link_to_patchs
209 page views in the last 30 days.

Was this page helpful?

Your feedback about this content is important. Let us know what you think.


Thank you!

We appreciate your feedback.