android Bluetooth

Basic :

Android Bluetooth provide support for Bluetooth network stack. it useful for exchange the data, audio or video wirelessly . The application framework provide the access the Bluetooth functionality and run over the android os. Bluetooth have point to point and multipoint wireless connection enabled.   

Functions :

1) Scan for the other bluetooth devices: for transfer the data wirelessly first of all it need to connect the that device which device having a data. for establish the connection the bluetooth scan for the that device.

2)Make a request for paired : after scanning the bluetooth the bluetooth send request for the make a paired. if that device accept that request it make a pair successfully.

3)Transfer the data: user can exchange the data between that point to point connections.

4) Manage the multipoint connection: Bluetooth provide the multipoint connection user can transfer the data multiply.   

permission for Bluetooth :

we need to permission to perform any Bluetooth connections.such transferring data connect the device and searching for the devices. if you want your app to initiated  device discovery or manipulated device setting you must declare Bluetooth admin permission most of device need to permission for discover able device

bluetooth permission example here:

<manifest ... >
  <uses-permission android:name="android.permission.BLUETOOTH" />
  ...</manifest>

Summary for bluetooth connections:

BluetoothAdapter

Represents the local Bluetooth adapter (Bluetooth radio). The BluetoothAdapter is the entry-point for all Bluetooth interaction. Using this, you can discover other Bluetooth devices, query a list of bonded (paired) devices, instantiate a BluetoothDevice using a known MAC address, and create a BluetoothServerSocketto listen for communications from other devices.

BluetoothDevice

Represents a remote Bluetooth device. Use this to request a connection with a remote device through aBluetoothSocket or query information about the device such as its name, address, class, and bonding state.

BluetoothSocket

Represents the interface for a Bluetooth socket (similar to a TCP Socket). This is the connection point that allows an application to exchange data with another Bluetooth device via InputStream and OutputStream.

BluetoothServerSocket

Represents an open server socket that listens for incoming requests (similar to a TCP ServerSocket). In order to connect two Android devices, one device must open a server socket with this class. When a remote Bluetooth device makes a connection request to the this device, the BluetoothServerSocket will return a connected BluetoothSocket when the connection is accepted.

BluetoothClass

Describes the general characteristics and capabilities of a Bluetooth device. This is a read-only set of properties that define the device's major and minor device classes and its services. However, this does not reliably describe all Bluetooth profiles and services supported by the device, but is useful as a hint to the device type.

BluetoothProfile

An interface that represents a Bluetooth profile. A Bluetooth profile is a wireless interface specification for Bluetooth-based communication between devices. An example is the Hands-Free profile. For more discussion of profiles, see Working with Profiles

BluetoothHeadset

Provides support for Bluetooth headsets to be used with mobile phones. This includes both Bluetooth Headset and Hands-Free (v1.5) profiles.

Bluetooth A2dp

Defines how high quality audio can be streamed from one device to another over a Bluetooth connection. "A2DP" stands for Advanced Audio Distribution Profile.

BluetoothHealth

Represents a Health Device Profile proxy that controls the Bluetooth service.

BluetoothHealthCallback

An abstract class that you use to implement BluetoothHealth callbacks. You must extend this class and implement the callback methods to receive updates about changes in the application’s registration state and Bluetooth channel state.

BluetoothHealthAppConfiguration

Represents an application configuration that the Bluetooth Health third-party application registers to communicate with a remote Bluetooth health device.

BluetoothProfile.ServiceListener

An interface that notifies BluetoothProfile IPC clients when they have been connected to or disconnected from the service (that is, the internal service that runs a particular profile).

How to display location address

Basic: 

After connecting the client apps to the location sensor and retrieve the client's current address then if you wants to get updates about your location in some particular interval time then you can turn on the updates.client wants to  turn off the updates then they can do the onpause() method for getting update.Here location object contain the longitude and latitude coordinates.these coordinates useful for the calculating map position  and location of the client. 

How to discover address:

for discover the the address we just need one progress bar and one text view in to the our main xml file progress bar shows the process of connecting the client position.for show intermediate activity tat show your app is working in background Set the initial state android:visibility="gone" to a make invisible and remove it from hierarchy.   

<ProgressBar
android:id="@+id/address_progress"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:indeterminate="true"
android:visibility="gone" />

Here create the subclass of that AsyncTask calls getFromLocation() the and return the address.define the text object maddress to contain the address and a progress bar object that you to control the intermediate activity indicator.

public class MainActivity extends FragmentActivity {
    ...
    private TextView mAddress;
    private ProgressBar mActivityIndicator;
    ...
    @Override
    protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    ...
    mAddress = (TextView) findViewById(R.id.address);
    mActivityIndicator =
            (ProgressBar) findViewById(R.id.address_progress);
    }
    ...
    /**
    * A subclass of AsyncTask that calls getFromLocation() in the
    * background. The class definition has these generic types:
    * Location - A Location object containing
    * the current location.
    * Void     - indicates that progress units are not used
    * String   - An address passed to onPostExecute()
    */
    private class GetAddressTask extends
            AsyncTask<Location, Void, String> {
        Context mContext;
        public GetAddressTask(Context context) {
            super();
            mContext = context;
        }
        ...
        /**
         * Get a Geocoder instance, get the latitude and longitude
         * look up the address, and return it
         *
         * @params params One or more Location objects
         * @return A string containing the address of the current
         * location, or an empty string if no address can be found,
         * or an error message
         */
        @Override
        protected String doInBackground(Location... params) {
            Geocoder geocoder =
                    new Geocoder(mContext, Locale.getDefault());
            // Get the current location from the input parameter list
            Location loc = params[0];
            // Create a list to contain the result address
            List<Address> addresses = null;
            try {
                /*
                 * Return 1 address.
                 */
                addresses = geocoder.getFromLocation(loc.getLatitude(),
                        loc.getLongitude(), 1);
            } catch (IOException e1) {
            Log.e("LocationSampleActivity",
                    "IO Exception in getFromLocation()");
            e1.printStackTrace();
            return ("IO Exception trying to get address");
            } catch (IllegalArgumentException e2) {
            // Error message to post in the log
            String errorString = "Illegal arguments " +
                    Double.toString(loc.getLatitude()) +
                    " , " +
                    Double.toString(loc.getLongitude()) +
                    " passed to address service";
            Log.e("LocationSampleActivity", errorString);
            e2.printStackTrace();
            return errorString;
            }
            // If the reverse geocode returned an address
            if (addresses != null && addresses.size() > 0) {
                // Get the first address
                Address address = addresses.get(0);
                /*
                 * Format the first line of address (if available),
                 * city, and country name.
                 */
                String addressText = String.format(
                        "%s, %s, %s",
                        // If there's a street address, add it
                        address.getMaxAddressLineIndex() > 0 ?
                                address.getAddressLine(0) : "",
                        // Locality is usually a city
                        address.getLocality(),
                        // The country of the address
                        address.getCountryName());
                // Return the text
                return addressText;
            } else {
                return "No address found";
            }
        }
        ...
    }
    ...
}

Method of display results:

doInBackground() this method return the result as string form.then this value pass in to onpostexecute().this onpostexecute() method run over the UI tread. this method call during the method retrieve something in back ground process. after gain the result this indicator turn off and display the result.

 private class GetAddressTask extends
            AsyncTask<Location, Void, String> {
        ...
        /**
         * A method that's called once doInBackground() completes. Turn
         * off the indeterminate activity indicator and set
         * the text of the UI element that shows the address. If the
         * lookup failed, display the error message.
         */
        @Override
        protected void onPostExecute(String address) {
            // Set activity indicator visibility to "gone"
            mActivityIndicator.setVisibility(View.GONE);
            // Display the results of the lookup.
            mAddress.setText(address);
        }
        ...
    }

Lookup task:

to get the execute() click on the button . after ten indicator display the application is now working . after then this process get the address using this coding .for get the address here geocoder services used.  

public class MainActivity extends FragmentActivity {
    ...
    /**
     * The "Get Address" button in the UI is defined with
     * android:onClick="getAddress". The method is invoked whenever the
     * user clicks the button.
     *
     * @param v The view object associated with this method,
     * in this case a Button.
     */
    public void getAddress(View v) {
        // Ensure that a Geocoder services is available
        if (Build.VERSION.SDK_INT >=
                Build.VERSION_CODES.GINGERBREAD
                            &&
                Geocoder.isPresent()) {
            // Show the activity indicator
            mActivityIndicator.setVisibility(View.VISIBLE);
            /*
             * Reverse geocoding is long-running and synchronous.
             * Run it on a background thread.
             * Pass the current location to the background task.
             * When the task finishes,
             * onPostExecute() displays the address.
             */
            (new GetAddressTask(this)).execute(mLocation);
        }
        ...
    }
    ...
}

Retrive the current location updates.

After implement the current location http://androidbasedapplication.blogspot.in/2014/09/how-to-add-location-in-your-application.html then we can retrive the updates about the location.   You can get the updates about your location with in periodic time slot.this app automatically update your location.last location update by  LocationClient.getLastLocation().   This location based on the currently available on wifi and GPS. The accuracy and frequency of updates are affected by location permissions tat you have requested and parameter you pass to location services with the request.

Set update:

For update the location of the client you must check the availability of google play services. for implement of the services refer this link  http://androidbasedapplication.blogspot.in/2014/09/how-to-add-location-in-your-application.html  . after find out the availability then define the location update callback. 

public class MainActivity extends FragmentActivity implements
        GooglePlayServicesClient.ConnectionCallbacks,
        GooglePlayServicesClient.OnConnectionFailedListener,
        LocationListener {
    ...
    // Define the callback method that receives location updates
    @Override
    public void onLocationChanged(Location location) {
        // Report to the UI that the location was updated
        String msg = "Updated Location: " +
                Double.toString(location.getLatitude()) + "," +
                Double.toString(location.getLongitude());
        Toast.makeText(this, msg, Toast.LENGTH_SHORT).show();
    }
    ...
}

for define the update callback onlocationchange() method used.the location object contain the client's longitude and latitude value then it used locationlistener interface used. Now your callback is prepared and you can set up the request for the location updates.before the starting the location update before then here specify some update parameter below

Update parameters:

Here we want update of the location is create in some regular interval so lets define the interval parameter.

Update interval :

This parameter set by locationrequest.setinterval(). This method set the millisecond interval time which your application prefer the receive the location updates.

Fastest interval update:

This parameter set by  locationrequest.setfastestinterval() and set the millisecond interval time. You just need to set this rate because other rate also affect the rate at which update are sent.If this rate is faster then you app can handle, you may encounter problems with UI flicker or data overflow. To prevent this call, LocationRequest.setFastestInterval() to set an upper limit to the upper rate.

public class MainActivity extends FragmentActivity implements
        GooglePlayServicesClient.ConnectionCallbacks,
        GooglePlayServicesClient.OnConnectionFailedListener,
        LocationListener {
    ...
    // Global constants
    ...
    // Milliseconds per second
    private static final int MILLISECONDS_PER_SECOND = 1000;
    // Update frequency in seconds
    public static final int UPDATE_INTERVAL_IN_SECONDS = 5;
    // Update frequency in milliseconds
    private static final long UPDATE_INTERVAL =
            MILLISECONDS_PER_SECOND * UPDATE_INTERVAL_IN_SECONDS;
    // The fastest update frequency, in seconds
    private static final int FASTEST_INTERVAL_IN_SECONDS = 1;
    // A fast frequency ceiling in milliseconds
    private static final long FASTEST_INTERVAL =
            MILLISECONDS_PER_SECOND * FASTEST_INTERVAL_IN_SECONDS;
    ...
    // Define an object that holds accuracy and frequency parameters
    LocationRequest mLocationRequest;
    ...
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // Create the LocationRequest object
        mLocationRequest = LocationRequest.create();
        // Use high accuracy
        mLocationRequest.setPriority(
                LocationRequest.PRIORITY_HIGH_ACCURACY);
        // Set the update interval to 5 seconds
        mLocationRequest.setInterval(UPDATE_INTERVAL);
        // Set the fastest update interval to 1 second
        mLocationRequest.setFastestInterval(FASTEST_INTERVAL);
        ...
    }
    ...
}

Start update location :

For get the location update you need to create the client's  location into the oncreate() method. Then connect it and calling the requestlocationupdate(). when client connect to the their app automatically client's location goes to in on start() method. for put the update request you need to call  it in  ConnectionCallbacks.onConnected() methods. If user wants to connect the location update with any reason then they can done easily in apps  SharedPreferences in onPause(). it can be start by  onResume().method.here below the coding display for the how to client's app goes into on create method and changes in to on start method.

  

public class MainActivity extends FragmentActivity implements
        GooglePlayServicesClient.ConnectionCallbacks,
        GooglePlayServicesClient.OnConnectionFailedListener,
        LocationListener {
    ...
    // Global variables
    ...
    LocationClient mLocationClient;
    boolean mUpdatesRequested;
    ...
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        ...
        // Open the shared preferences
        mPrefs = getSharedPreferences("SharedPreferences",
                Context.MODE_PRIVATE);
        // Get a SharedPreferences editor
        mEditor = mPrefs.edit();
        /*
         * Create a new location client, using the enclosing class to
         * handle callbacks.
         */
        mLocationClient = new LocationClient(this, this, this);
        // Start with updates turned off
        mUpdatesRequested = false;
        ...
    }
    ...
    @Override
    protected void onPause() {
        // Save the current setting for updates
        mEditor.putBoolean("KEY_UPDATES_ON", mUpdatesRequested);
        mEditor.commit();
        super.onPause();
    }
    ...
    @Override
    protected void onStart() {
        ...
        mLocationClient.connect();
    }
    ...
    @Override
    protected void onResume() {
        /*
         * Get any previous setting for location updates
         * Gets "false" if an error occurs
         */
        if (mPrefs.contains("KEY_UPDATES_ON")) {
            mUpdatesRequested =
                    mPrefs.getBoolean("KEY_UPDATES_ON", false);

        // Otherwise, turn off location updates
        } else {
            mEditor.putBoolean("KEY_UPDATES_ON", false);
            mEditor.commit();
        }
    }
    ...
    /*
     * Called by Location Services when the request to connect the
     * client finishes successfully. At this point, you can
     * request the current location or start periodic updates
     */
    @Override
    public void onConnected(Bundle dataBundle) {
        // Display the connection status
        Toast.makeText(this, "Connected", Toast.LENGTH_SHORT).show();
        // If already requested, start periodic updates
        if (mUpdatesRequested) {
            mLocationClient.requestLocationUpdates(mLocationRequest, this);
        }
    }
    ...
}

Stop update location:

User wants to turn off location updates then the state of update flag save in to the onPause(). for make the the stop update in onstop() by calling removeLocationUpdates(LocationListener).

public class MainActivity extends FragmentActivity implements
        GooglePlayServicesClient.ConnectionCallbacks,
        GooglePlayServicesClient.OnConnectionFailedListener,
        LocationListener {
    ...
    /*
     * Called when the Activity is no longer visible at all.
     * Stop updates and disconnect.
     */
    @Override
    protected void onStop() {
        // If the client is connected
        if (mLocationClient.isConnected()) {
            /*
             * Remove location updates for a listener.
             * The current Activity is the listener, so
             * the argument is "this".
             */
            removeLocationUpdates(this);
        }
        /*
         * After disconnect() is called, the client is
         * considered "dead".
         */
        mLocationClient.disconnect();
        super.onStop();
    }
    ...
}

In this post you have the basic  structure of the how client connect to the on create get the update and turn off the update location.

How to add location in your application

Android mobile has many new features and many new technologies use. one of the most useful features is that add the your location in your mobile phones or a android application. you can go anywhere and you easily pin your current location in social sites or professional work.android os provide the tracking system and find out the path for your destination.

Retrieving current location :

This api maintain the automatically user's current location.The accuracy of the retrieve the current location of the user is based on the how location sensor work and the location permission which done by the users.for find out the users current location we need the LocationClient class . instance of this class is carried out the location of users and deliver to application.

How to get permission in the application :

Android has two types of permission for retrieving the current location. both permission is here  ACCESS_FINE_LOCATION. and ACCESS_COARSE_LOCATION choose any one and retrieve the current location.user permission add into the manifest element by this syntax. for get the more accurate current location use the fine location permission. 

<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>

 Check for google play service:

location service is part of the google map apk. so you need to check for install the apk before the location service is being for check apk is installed call the this function   GooglePlayServicesUtil.isGooglePlayServicesAvailable(), It returns the resultcode for the connection results if error is fired the call GooglePlayServicesUtil.getErrorDialog().Here give the snippets given in below is useful for the check the google play service.

public class MainActivity extends FragmentActivity {
    ...
    // Global constants
    /*
     * Define a request code to send to Google Play services
     * This code is returned in Activity.onActivityResult
     */
    private final static int
            CONNECTION_FAILURE_RESOLUTION_REQUEST = 9000;
    ...
    // Define a DialogFragment that displays the error dialog
    public static class ErrorDialogFragment extends DialogFragment {
        // Global field to contain the error dialog
        private Dialog mDialog;
        // Default constructor. Sets the dialog field to null
        public ErrorDialogFragment() {
            super();
            mDialog = null;
        }
        // Set the dialog to display
        public void setDialog(Dialog dialog) {
            mDialog = dialog;
        }
        // Return a Dialog to the DialogFragment.
        @Override
        public Dialog onCreateDialog(Bundle savedInstanceState) {
            return mDialog;
        }
    }
    ...
    /*
     * Handle results returned to the FragmentActivity
     * by Google Play services
     */
    @Override
    protected void onActivityResult(
            int requestCode, int resultCode, Intent data) {
        // Decide what to do based on the original request code
        switch (requestCode) {
            ...
            case CONNECTION_FAILURE_RESOLUTION_REQUEST :
            /*
             * If the result code is Activity.RESULT_OK, try
             * to connect again
             */
                switch (resultCode) {
                    case Activity.RESULT_OK :
                    /*
                     * Try the request again
                     */
                    ...
                    break;
                }
            ...
        }
     }
    ...
    private boolean servicesConnected() {
        // Check that Google Play services is available
        int resultCode =
                GooglePlayServicesUtil.
                        isGooglePlayServicesAvailable(this);
        // If Google Play services is available
        if (ConnectionResult.SUCCESS == resultCode) {
            // In debug mode, log the status
            Log.d("Location Updates",
                    "Google Play services is available.");
            // Continue
            return true;
        // Google Play services was not available for some reason.
        // resultCode holds the error code.
        } else {
            // Get the error dialog from Google Play services
            Dialog errorDialog = GooglePlayServicesUtil.getErrorDialog(
                    resultCode,
                    this,
                    CONNECTION_FAILURE_RESOLUTION_REQUEST);

            // If Google Play services can provide an error dialog
            if (errorDialog != null) {
                // Create a new DialogFragment for the error dialog
                ErrorDialogFragment errorFragment =
                        new ErrorDialogFragment();
                // Set the dialog in the DialogFragment
                errorFragment.setDialog(errorDialog);
                // Show the error dialog in the DialogFragment
                errorFragment.show(getSupportFragmentManager(),
                        "Location Updates");
            }
        }
    }
    ...
}

Location services :

To get the current location of the client frist of all its connect to location services.tis sevices used the getLastLocation() method.Its return the latest and best value .For retrieve the location you just need the turn on the current locat5ion sensor.

Here 2 interface are specified ConnectionCallbacks and OnConnectionFailedListener in this methods.

public class MainActivity extends FragmentActivity implements
        GooglePlayServicesClient.ConnectionCallbacks,
        GooglePlayServicesClient.OnConnectionFailedListener {
    ...
    /*
     * Called by Location Services when the request to connect the
     * client finishes successfully. At this point, you can
     * request the current location or start periodic updates
     */
    @Override
    public void onConnected(Bundle dataBundle) {
        // Display the connection status
        Toast.makeText(this, "Connected", Toast.LENGTH_SHORT).show();

    }
    ...
    /*
     * Called by Location Services if the connection to the
     * location client drops because of an error.
     */
    @Override
    public void onDisconnected() {
        // Display the connection status
        Toast.makeText(this, "Disconnected. Please re-connect.",
                Toast.LENGTH_SHORT).show();
    }
    ...
    /*
     * Called by Location Services if the attempt to
     * Location Services fails.
     */
    @Override
    public void onConnectionFailed(ConnectionResult connectionResult) {
        /*
         * Google Play services can resolve some errors it detects.
         * If the error has a resolution, try sending an Intent to
         * start a Google Play services activity that can resolve
         * error.
         */
        if (connectionResult.hasResolution()) {
            try {
                // Start an Activity that tries to resolve the error
                connectionResult.startResolutionForResult(
                        this,
                        CONNECTION_FAILURE_RESOLUTION_REQUEST);
                /*
                 * Thrown if Google Play services canceled the original
                 * PendingIntent
                 */
            } catch (IntentSender.SendIntentException e) {
                // Log the error
                e.printStackTrace();
            }
        } else {
            /*
             * If no resolution is available, display a dialog to the
             * user with the error.
             */
            showErrorDialog(connectionResult.getErrorCode());
        }
    }
    ...
}

How to connect the location client :

Here 3 m3thod are created ... onCreate() ,onstart() and onstop methods.YOu should create the location client in oncreate(0 and it goes to onstart() mode and retrieve the recent user's location. LOcation sensor maintain the current location of the user's and make visible it . after then disconnect to the client it called the onstop().it means now location services not maintain the current location.

public class MainActivity extends FragmentActivity implements
        GooglePlayServicesClient.ConnectionCallbacks,
        GooglePlayServicesClient.OnConnectionFailedListener {
    ...
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        ...
        /*
         * Create a new location client, using the enclosing class to
         * handle callbacks.
         */
        mLocationClient = new LocationClient(this, this, this);
        ...
    }
    ...
    /*
     * Called when the Activity becomes visible.
     */
    @Override
    protected void onStart() {
        super.onStart();
        // Connect the client.
        mLocationClient.connect();
    }
    ...
    /*
     * Called when the Activity is no longer visible.
     */
    @Override
    protected void onStop() {
        // Disconnecting the client invalidates it.
        mLocationClient.disconnect();
        super.onStop();
    }
    ...
}

Get the current location :

After the implement in the location services then it time to get the current location.For retrive the recent current location call the getloaction() methods. 

public class MainActivity extends FragmentActivity implements
        GooglePlayServicesClient.ConnectionCallbacks,
        GooglePlayServicesClient.OnConnectionFailedListener {
    ...
    // Global variable to hold the current location
    Location mCurrentLocation;
    ...
    mCurrentLocation = mLocationClient.getLastLocation();
    ...
}

implement all this method you will get the current location of your's. you just need the data usages permission and the location sensor make turn on.after the you will get the most recent and best value of your location.