BlueTooth example which scans for available devices

Blue1Activity.java
------------------------
package com.blue;

import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

public class Blue1Activity extends Activity {

    private TextView tv1;
    private Button search;
    private static final int REQUEST_ENABLE_BT = 3;
    private BluetoothAdapter mBluetoothAdapter = null;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        tv1 = (TextView) findViewById(R.id.textView1);
        search = (Button) findViewById(R.id.button1);
        // Get local Bluetooth adapter
        mBluetoothAdapter = BluetoothAdapter.getDefaultAdapter();

        // If the adapter is null, then Bluetooth is not supported
        if (mBluetoothAdapter == null) {
            Toast.makeText(this, "Bluetooth is not available",
                    Toast.LENGTH_LONG).show();
            finish();
            return;

        } else {
            int name = mBluetoothAdapter.getState();

            Log.i("tag", mBluetoothAdapter.STATE_OFF + "");

            if (name == mBluetoothAdapter.STATE_OFF) {
                tv1.setText("blue tooth is off");
                if (!mBluetoothAdapter.isEnabled()) {
                    Intent enableIntent = new Intent(
                            BluetoothAdapter.ACTION_REQUEST_ENABLE);
                    startActivityForResult(enableIntent, REQUEST_ENABLE_BT);
                }

            } else if (name == mBluetoothAdapter.STATE_ON) {
                tv1.setText("blue tooth is on");
            }

            Toast.makeText(this, "Bluetooth is  available", Toast.LENGTH_LONG)
                    .show();
        }
        search.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                Intent intent = new Intent(Blue1Activity.this,
                        paireddevices.class);
                startActivityForResult(intent, 1);

            }
        });
    }

}

Paireddevices.java
-----------------------
package com.blue;

import java.util.Set;

import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.Window;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.AdapterView.OnItemClickListener;

public class paireddevices extends Activity {
    // Debugging
    private static final String TAG = "DeviceListActivity";
    private static final boolean D = true;

    // Return Intent extra
    public static String EXTRA_DEVICE_ADDRESS = "device_address";

    // Member fields
    private BluetoothAdapter mBtAdapter;
    private ArrayAdapter<String> mPairedDevicesArrayAdapter;
    private ArrayAdapter<String> mNewDevicesArrayAdapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Setup the window
        requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
        setContentView(R.layout.device_list);

        // Set result CANCELED in case the user backs out
        setResult(Activity.RESULT_CANCELED);

        // Initialize the button to perform device discovery
        Button scanButton = (Button) findViewById(R.id.button_scan);
        scanButton.setOnClickListener(new OnClickListener() {
            public void onClick(View v) {
                doDiscovery();
                v.setVisibility(View.GONE);
            }
        });

        // Initialize array adapters. One for already paired devices and
        // one for newly discovered devices
        mPairedDevicesArrayAdapter = new ArrayAdapter<String>(this,
                R.layout.device_name);
        mNewDevicesArrayAdapter = new ArrayAdapter<String>(this,
                R.layout.device_name);

        // Find and set up the ListView for paired devices
        ListView pairedListView = (ListView) findViewById(R.id.paired_devices);
        pairedListView.setAdapter(mPairedDevicesArrayAdapter);
        pairedListView.setOnItemClickListener(mDeviceClickListener);

        // Find and set up the ListView for newly discovered devices
        ListView newDevicesListView = (ListView) findViewById(R.id.new_devices);
        newDevicesListView.setAdapter(mNewDevicesArrayAdapter);
        newDevicesListView.setOnItemClickListener(mDeviceClickListener);

        // Register for broadcasts when a device is discovered
        IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND);
        this.registerReceiver(mReceiver, filter);

        // Register for broadcasts when discovery has finished
        filter = new IntentFilter(BluetoothAdapter.ACTION_DISCOVERY_FINISHED);
        this.registerReceiver(mReceiver, filter);

        // Get the local Bluetooth adapter
        mBtAdapter = BluetoothAdapter.getDefaultAdapter();

        // Get a set of currently paired devices
        Set<BluetoothDevice> pairedDevices = mBtAdapter.getBondedDevices();

        // If there are paired devices, add each one to the ArrayAdapter
        if (pairedDevices.size() > 0) {
            findViewById(R.id.title_paired_devices).setVisibility(View.VISIBLE);
            for (BluetoothDevice device : pairedDevices) {
                mPairedDevicesArrayAdapter.add(device.getName() + "\n"
                        + device.getAddress());
            }
        } else {
            String noDevices = getResources().getText(R.string.none_paired)
                    .toString();
            mPairedDevicesArrayAdapter.add(noDevices);
        }
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();

        // Make sure we're not doing discovery anymore
        if (mBtAdapter != null) {
            mBtAdapter.cancelDiscovery();
        }

        // Unregister broadcast listeners
        this.unregisterReceiver(mReceiver);
    }

    /**
     * Start device discover with the BluetoothAdapter
     */
    private void doDiscovery() {
        if (D)
            Log.d(TAG, "doDiscovery()");

        // Indicate scanning in the title
        setProgressBarIndeterminateVisibility(true);
        setTitle(R.string.scanning);

        // Turn on sub-title for new devices
        findViewById(R.id.title_new_devices).setVisibility(View.VISIBLE);

        // If we're already discovering, stop it
        if (mBtAdapter.isDiscovering()) {
            mBtAdapter.cancelDiscovery();
        }

        // Request discover from BluetoothAdapter
        mBtAdapter.startDiscovery();
    }

    // The on-click listener for all devices in the ListViews
    private OnItemClickListener mDeviceClickListener = new OnItemClickListener() {
        public void onItemClick(AdapterView<?> av, View v, int arg2, long arg3) {
            // Cancel discovery because it's costly and we're about to connect
            mBtAdapter.cancelDiscovery();

            // Get the device MAC address, which is the last 17 chars in the
            // View
            String info = ((TextView) v).getText().toString();
            String address = info.substring(info.length() - 17);

            // Create the result Intent and include the MAC address
            Intent intent = new Intent();
            intent.putExtra(EXTRA_DEVICE_ADDRESS, address);

            // Set result and finish this Activity
            setResult(Activity.RESULT_OK, intent);
            finish();
        }
    };

    // The BroadcastReceiver that listens for discovered devices and
    // changes the title when discovery is finished
    private final BroadcastReceiver mReceiver = new BroadcastReceiver() {
        @Override
        public void onReceive(Context context, Intent intent) {
            String action = intent.getAction();

            // When discovery finds a device
            if (BluetoothDevice.ACTION_FOUND.equals(action)) {
                // Get the BluetoothDevice object from the Intent
                BluetoothDevice device = intent
                        .getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
                // If it's already paired, skip it, because it's been listed
                // already
                if (device.getBondState() != BluetoothDevice.BOND_BONDED) {
                    mNewDevicesArrayAdapter.add(device.getName() + "\n"
                            + device.getAddress());
                }
                // When discovery is finished, change the Activity title
            } else if (BluetoothAdapter.ACTION_DISCOVERY_FINISHED
                    .equals(action)) {
                setProgressBarIndeterminateVisibility(false);
                setTitle(R.string.select_device);
                if (mNewDevicesArrayAdapter.getCount() == 0) {
                    String noDevices = getResources().getText(
                            R.string.none_found).toString();
                    mNewDevicesArrayAdapter.add(noDevices);
                }
            }
        }
    };

}

device_list.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/title_paired_devices"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#666"
        android:paddingLeft="5dp"
        android:text="@string/title_paired_devices"
        android:textColor="#fff"
        android:visibility="gone" />

    <ListView
        android:id="@+id/paired_devices"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:stackFromBottom="true" />

    <TextView
        android:id="@+id/title_new_devices"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="#666"
        android:paddingLeft="5dp"
        android:text="@string/title_other_devices"
        android:textColor="#fff"
        android:visibility="gone" />

    <ListView
        android:id="@+id/new_devices"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_weight="2"
        scroll=""
        android:stackFromBottom="true" />

    <Button
        android:id="@+id/button_scan"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/button_scan" />

</LinearLayout>

device_name.xml

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:textSize="18sp"
    android:padding="5dp"
/>

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

  

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="TextView" />

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Click to see available devices" />

</LinearLayout>