title: Discovering Bluetooth devices lists duplicate names
body: <p>I am using DeviceListActivity for discovering Bluetooth devices. This is the activity that is used on Android Bluetooth Chat program sample.</p>
  
  <p>I run the program on a virtual machine. </p>
  
  <p><strong>Problem:</strong> When I start scanning/discovering Bluetooth devices:</p>
  
  <p><img src="https://i.stack.imgur.com/dtP3g.jpg" alt="enter image description here"></p>
  
  <p>it lists duplicate devices name:</p>
  
  <p><img src="https://i.stack.imgur.com/cIMJr.jpg" alt="enter image description here"></p>
  
  <p>I have one device that is discoverable but the program lists it more than once.</p>
  
  <p><strong>How can I prevent to list duplicate devices name?</strong></p>
  
  <p>The activity code:</p>
  
  <pre><code>package com.example.android.BluetoothChat;
  
  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;
  
  /**
   * This Activity appears as a dialog. It lists any paired devices and
   * devices detected in the area after discovery. When a device is chosen
   * by the user, the MAC address of the device is sent back to the parent
   * Activity in the result Intent.
   */
  public class DeviceListActivity 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&lt;String&gt; mPairedDevicesArrayAdapter;
      private ArrayAdapter&lt;String&gt; 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 incase 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&lt;String&gt;(this, R.layout.device_name);
          mNewDevicesArrayAdapter = new ArrayAdapter&lt;String&gt;(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&lt;BluetoothDevice&gt; pairedDevices = mBtAdapter.getBondedDevices();
  
          // If there are paired devices, add each one to the ArrayAdapter
          if (pairedDevices.size() &gt; 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&lt;?&gt; 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);
                  }
              }
          }
      };
  
  }
  </code></pre>
  
  <p><strong>Edit:</strong>
  This problem is disappeared on my real device(smart phone). I don't know why an emulator has such problem!</p>