Control Volume Code for J2ME - mobile

Question

I have nokia xpressmusic 5130 c-2 working on symbian (j2me) the volume buttons has been broken, so i decided to make a j2me program to control the volume (increase,decrease)
I have found many codes through the internet but often not work or have many errors because not complied with the program flow diagram and screen
regards

Answer 1

If the device have support to the JSR 256: Mobile Sensor API, then you can use your API:
http://jcp.org/en/jsr/detail?id=256
My class that uses the JSR 256:
/*
* REVISION HISTORY:
*
* Date Author(s)
* CR Headline
* =============================================================================
* 22/Oct/2009 Douglas Daniel Del Frari
* <CR51674> Initial Version
* =============================================================================
* 25/Feb/2010 Douglas Daniel Del Frari
* <CR52577> Added more one sensor (charge state) to detection of charger state.
* =============================================================================
*/
package j2me.mobilesensor;
import java.io.IOException;
import javax.microedition.io.Connector;
import javax.microedition.sensor.Data;
import javax.microedition.sensor.DataListener;
import javax.microedition.sensor.SensorConnection;
import javax.microedition.sensor.SensorInfo;
import javax.microedition.sensor.SensorManager;
/**
* This class uses the resource of the mobile sensor (JSR-256) to capture the
* phone battery level, and the volume level of the phone
*
* #author Douglas D. Del Frari (douglas.frari#gmail.com)
*/
public class MobileSensorManager implements DataListener, Runnable{
/** ID for the alert dialog */
public static final int ID_DIALOG_BATTERY_CHARGE = 90;
/**
* String used to get the battery charge level.
*/
private static final String BATTERY = "battery_charge";
/**
* String used to get the charger state (plugged on or off).
*/
private static final String BATTERY_CHARGER_STATE = "charger_state";
/**
* String used to get the sound level
*/
private static final String SOUND_LEVEL = "sound_level_setting";
// sensors
private static SensorConnection batterySensor = null;
private SensorConnection soundSensor = null;
// SensorInfo objects containing info about
private SensorInfo infos[];
// Is sensor thread running?
private static boolean isStopped = false;
// Buffer for the sensor data
private static final int BUFFER_SIZE = 1;
/**
* Indicate the minimal value of battery level of the game
*/
public static final int BATTERY_LIFE_LIMIT = 25;
// Thread for initializing and listening
private Thread thread = null;
/*
* Sensor quantity string received from the dataReceived() method
*/
private String sensorString = "";
// Sensor value (battery_charge)
private String batteryString = "";
private String volumeString = "";
private boolean isActiveBatterySensor;
private boolean isLowBatteryCharge;
private int batteryChargeValue;
private int volumeValue;
private SensorConnection batteryChargerState;
private boolean chargeState;
// instance this class
private static MobileSensorManager instance;
/**
* default constructor
*/
private MobileSensorManager() {
}
/**
* Get the MobileSensorManager instance
*
* #return instance this
*/
public static MobileSensorManager getInstance() {
if (instance == null) {
instance = new MobileSensorManager();
}
return instance;
}
/**
* #param stopped
*/
private synchronized void setStopped(boolean stopped) {
isStopped = stopped;
notify();
if (thread != null)
thread = null;
}
/**
* start the mobile sensors
*/
public synchronized void start() {
setStopped(false);
if (thread == null)
thread = new Thread(this);
thread.start();
}
/**
* stop the mobile sensors
*/
public synchronized void stop() {
setStopped(true);
thread = null;
}
/* (non-Javadoc)
* #see java.lang.Runnable#run()
*/
public void run() {
initSensors();
}
/**
* Initializes (opens) the sensors and sets the DataListener. Takes also
* care of removing the DataListeners and closing the connections
*/
private synchronized void initSensors() {
batterySensor = openSensor(BATTERY);
if (batterySensor == null) {
isActiveBatterySensor = false;
return;
} else {
isActiveBatterySensor = true;
}
batteryChargerState = openSensor(BATTERY_CHARGER_STATE);
soundSensor = openSensor(SOUND_LEVEL);
try {
batterySensor.setDataListener(this, BUFFER_SIZE);
if (soundSensor !=null) {
soundSensor.setDataListener(this, BUFFER_SIZE);
}
if (batteryChargerState != null) {
batteryChargerState.setDataListener(this, BUFFER_SIZE);
}
while (!isStopped) {
try {
wait();
} catch (InterruptedException ie) {
}
}
batterySensor.removeDataListener();
if (soundSensor !=null) {
soundSensor.removeDataListener();
}
if (batteryChargerState != null) {
batteryChargerState.removeDataListener();
}
} catch (IllegalMonitorStateException imse) {
imse.printStackTrace();
} catch (IllegalArgumentException iae) {
iae.printStackTrace();
}
try {
if (batterySensor!=null) {
batterySensor.close();
}
if (soundSensor !=null) {
soundSensor.close();
}
if (batteryChargerState != null) {
batteryChargerState.close();
}
} catch (IOException ioe) {
ioe.printStackTrace();
}
if (isStopped) {
batterySensor = null;
soundSensor = null;
batteryChargerState = null;
}
}
/**
* Searches sensors of desired quantity and if found returns a
* SensorConnection opened to it.
*
* #return SensorConnection, which has been opened to a sensor matching the
* criteria
*/
private SensorConnection openSensor(String quantity) {
infos = SensorManager.findSensors(quantity, null);
if (infos.length == 0)
return null;
String sensor_url = infos[0].getUrl();
try {
return (SensorConnection) Connector.open(sensor_url);
} catch (IOException ioe) {
ioe.printStackTrace();
return null;
}
}
/* (non-Javadoc)
* #see javax.microedition.sensor.DataListener#dataReceived(javax.microedition.sensor.SensorConnection, javax.microedition.sensor.Data[], boolean)
*/
public void dataReceived(SensorConnection sensor, Data[] data, boolean isDataLost) {
sensorString = sensor.getSensorInfo().getQuantity();
int values[] = data[0].getIntValues();
if (sensorString.equals(BATTERY)) {
setBatteryString("" + values[0] + "%");
batteryChargeValue = values[0];
}
if (sensorString.equals(SOUND_LEVEL)) {
setVolumeString("" + values[0] + " sound level");
volumeValue = values[0];
}
if (sensorString.equals(BATTERY_CHARGER_STATE)) {
int value = values[0];
if (value == 0)
chargeState = false;
else if (value == 1)
chargeState = true;
}
if (values[0] <= BATTERY_LIFE_LIMIT) {
isLowBatteryCharge = true;
} else {
isLowBatteryCharge = false;
}
}
/**
* #return the batteryString
*/
public String getBatteryString() {
return batteryString;
}
/**
* #param batteryString the batteryString to set
*/
public void setBatteryString(String batteryString) {
this.batteryString = batteryString;
}
/**
* #return the isLowBatteryCharge
*/
public boolean isLowBatteryCharge() {
return isLowBatteryCharge;
}
/**
* #return the isActiveBatterySensor
*/
public boolean isActiveBatterySensor() {
return isActiveBatterySensor;
}
/**
* #return the batteryChargeValue
*/
public int getBatteryChargeValue() {
return batteryChargeValue;
}
/**
* #param volumeString the volumeString to set
*/
public void setVolumeString(String volumeString) {
this.volumeString = volumeString;
}
/**
* #return the volumeString
*/
public String getVolumeString() {
return volumeString;
}
/**
* #param volumeValue the volumeValue to set
*/
public void setVolumeValue(int volumeValue) {
this.volumeValue = volumeValue;
}
/**
* #return the volumeValue
*/
public int getVolumeValue() {
return volumeValue;
}
/**
* Get state of battery charge
*
* #return True if the charge is plugged in, otherwise not plugged in
*/
public boolean isChargedState() {
return chargeState;
}
}