Android Studio Bluetooth startDiscovey not working - android-studio

Question

In my code, after I run startDiscovery().
Nothing seems to happen and I don't know why.
As #Mitch suggest, I changed back to using button to do startDiscovery.
But now it seems worse as it crashes right after I press the button.
public class BTActivity extends AppCompatActivity{
private static final String TAG = "BTActivity";
BluetoothAdapter BTAdapter;
public ArrayList<BluetoothDevice> mBTDevices = new ArrayList<>();
public DeviceListAdapter mDeviceListAdapter;
ListView lvNewDevices;
private EcgView mEcgView;
//Create a BroadcastReceiver for
private final BroadcastReceiver mBroadcastReceiver1 = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (action.equals(BTAdapter.ACTION_STATE_CHANGED)){
final int state = intent.getIntExtra(BluetoothAdapter.EXTRA_STATE, BTAdapter.ERROR);
switch (state){
case BluetoothAdapter.STATE_OFF:
Log.d(TAG,"onReceive: STATE OFF");
break;
case BluetoothAdapter.STATE_TURNING_OFF:
Log.d(TAG,"onReceive: STATE TURNING OFF");
break;
case BluetoothAdapter.STATE_ON:
Log.d(TAG,"onReceive: STATE ON");
break;
case BluetoothAdapter.STATE_TURNING_ON:
Log.d(TAG,"onReceive: STATE TURNING ON");
break;
}
}
}
};
private final BroadcastReceiver mBroadcastReceiver2 = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
final String action = intent.getAction();
if (action.equals(BluetoothAdapter.ACTION_SCAN_MODE_CHANGED)){
int mode = intent.getIntExtra(BluetoothAdapter.EXTRA_SCAN_MODE, BluetoothAdapter.ERROR);
switch (mode){
case BluetoothAdapter.SCAN_MODE_CONNECTABLE_DISCOVERABLE:
Log.d(TAG,"mBroadcastReceiver2: Discoverability Enabled");
break;
case BluetoothAdapter.SCAN_MODE_CONNECTABLE:
Log.d(TAG,"mBroadcastReceiver2: Discoverability Disabled. Able to receive connection");
break;
case BluetoothAdapter.SCAN_MODE_NONE:
Log.d(TAG,"mBroadcastReceiver2: Discoverability Disabled. Not able to receive connection");
break;
case BluetoothAdapter.STATE_CONNECTING:
Log.d(TAG,"mBroadcastReceiver2: Connecting");
break;
case BluetoothAdapter.STATE_CONNECTED:
Log.d(TAG,"mBroadcastReceiver2: Connected");
break;
}
}
}
};
private final BroadcastReceiver mBroadcastReceiver3 = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
final String action = intent.getAction();
Log.d(TAG, "OnReceive: ACTION FOUND");
if (action.equals(BluetoothDevice.ACTION_FOUND)) {
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
mBTDevices.add(device);
Log.d(TAG, "OnReceive: " + device.getName() + ": " + device.getAddress());
mDeviceListAdapter = new DeviceListAdapter(context, R.layout.device_adapter_view, mBTDevices);
lvNewDevices.setAdapter(mDeviceListAdapter);
}
}
};
private final BroadcastReceiver mBroadcastReceiver4 = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (action.equals(BluetoothDevice.ACTION_BOND_STATE_CHANGED)) {
BluetoothDevice mDevice = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
//3cases:
if (mDevice.getBondState() == BluetoothDevice.BOND_BONDED){
Log.d(TAG, "BroadcastReceiver: BOND_BOUNDED");
}
if (mDevice.getBondState() == BluetoothDevice.BOND_BONDING){
Log.d(TAG, "BroadcastReceiver: BOND_BOUNDING");
}
if (mDevice.getBondState() == BluetoothDevice.BOND_NONE){
Log.d(TAG, "BroadcastReceiver: BOND_NONE");
}
}
}
};
protected void onDestroy(){
super.onDestroy();
unregisterReceiver(mBroadcastReceiver1);
unregisterReceiver(mBroadcastReceiver2);
unregisterReceiver(mBroadcastReceiver3);
unregisterReceiver(mBroadcastReceiver4);
}
public boolean onCreateOptionsMenu (Menu menu){
MenuInflater menuInflater = getMenuInflater();
menuInflater.inflate(R.menu.main_menu,menu);
return super.onCreateOptionsMenu(menu);
}
public boolean onOptionsItemSelected(MenuItem item) {
super.onOptionsItemSelected(item);
switch (item.getItemId()) {
case R.id.enabledisable:
//if BT is enable, turn it off; if not then prompt user to enable BT;
if (!BTAdapter.getDefaultAdapter().isEnabled()) {
Intent i = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivity(i);
IntentFilter BTIntent = new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED);
registerReceiver(mBroadcastReceiver1, BTIntent);
}
if(BTAdapter.getDefaultAdapter().isEnabled()) {
BTAdapter.getDefaultAdapter().disable();
IntentFilter BTIntent = new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED);
registerReceiver(mBroadcastReceiver1, BTIntent);
}
return true;
case R.id.enablediscoverable:
Intent discoverableIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_DISCOVERABLE);
discoverableIntent.putExtra(BluetoothAdapter.EXTRA_DISCOVERABLE_DURATION, 300);
startActivity(discoverableIntent);
IntentFilter intentFilter = new IntentFilter(BTAdapter.ACTION_SCAN_MODE_CHANGED);
registerReceiver(mBroadcastReceiver2, intentFilter);
return true;
case R.id.discover:
Intent intent = new Intent(getApplicationContext(),SearchActivity.class);
startActivity(intent);
/*
Log.d(TAG,"Looking for unpaired devices");
if (BTAdapter.isDiscovering()){
BTAdapter.cancelDiscovery();
Log.d(TAG,"Canceling Discovery");
//checkBTPermissions();
BTAdapter.startDiscovery();
IntentFilter discoverDevicesIntent = new IntentFilter(BluetoothDevice.ACTION_FOUND);
registerReceiver(mBroadcastReceiver3, discoverDevicesIntent);
}
if (!BTAdapter.isDiscovering()){
//checkBTPermissions();
Log.d(TAG,"Searching Now");
BTAdapter.startDiscovery();
Log.d(TAG,"Still Searching Now");
IntentFilter discoverDevicesIntent = new IntentFilter(BluetoothDevice.ACTION_FOUND);
registerReceiver(mBroadcastReceiver3, discoverDevicesIntent);
Log.d(TAG,"123");
}
*/
return true;
default:
return false;
}
}
/*
private void checkBTPermissions() {
if (Build.VERSION.SDK_INT > Build.VERSION_CODES.LOLLIPOP){
int permissionCheck = this.checkSelfPermission("Manifest.permission.ACCESS_FINE_LOCATATION");
permissionCheck += this.checkSelfPermission("Manifest.permission.ACCESS_COARSE_LOCATION");
if (permissionCheck != 0){
this.requestPermissions(new String[]{Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION}, 1001);
}
else{
Log.d(TAG, "checkBTPermissions: No need to check permissions. SDK Version < LOLLIPOP");
}
}
}
*/
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_bt);
lvNewDevices = (ListView) findViewById(R.id.lvNewDevices);
mBTDevices = new ArrayList<>();
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_BOND_STATE_CHANGED);
registerReceiver(mBroadcastReceiver4,filter);
//lvNewDevices.setOnItemClickListener(BTActivity.this);
//Check if the phone support BT
BTAdapter = BluetoothAdapter.getDefaultAdapter();
if (BTAdapter == null) {
//System.exit(0);
}
//mConnectThread = new ConnectThread(mDevice);
//mConnectThread.start();
mEcgView = (EcgView) findViewById(R.id.ecgView);
}
public void toMainActivity(View view){
Intent intent = new Intent(getApplicationContext(),MainActivity.class);
startActivity(intent);
}
}
So after the click on the Search Devices from the action bar, the app will go to another activity. But when I click on Start Searching in that activity, the app crashes. Don't know why as logic should be the same.
public class SearchActivity extends AppCompatActivity implements AdapterView.OnItemClickListener {
private static final String TAG = "SearchActivity";
BluetoothAdapter BTAdapter;
public ArrayList<BluetoothDevice> mBTDevices = new ArrayList<>();
public DeviceListAdapter mDeviceListAdapter;
ListView lvNewDevices;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_search);
lvNewDevices = (ListView) findViewById(R.id.lvNewDevices);
mBTDevices = new ArrayList<>();
lvNewDevices.setOnItemClickListener(SearchActivity.this);
}
private final BroadcastReceiver mBroadcastReceiver3 = new BroadcastReceiver() {
#Override
public void onReceive(Context context, Intent intent) {
final String action = intent.getAction();
Log.d(TAG, "OnReceive: ACTION FOUND");
if (action.equals(BluetoothDevice.ACTION_FOUND)) {
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
mBTDevices.add(device);
Log.d(TAG, "OnReceive: " + device.getName() + ": " + device.getAddress());
mDeviceListAdapter = new DeviceListAdapter(context, R.layout.device_adapter_view, mBTDevices);
lvNewDevices.setAdapter(mDeviceListAdapter);
}
}
};
public void btnDiscover(View view){
Log.d(TAG,"Looking for unpaired devices");
if (BTAdapter.isDiscovering()){
BTAdapter.cancelDiscovery();
Log.d(TAG,"Canceling Discovery");
//checkBTPermissions();
BTAdapter.startDiscovery();
IntentFilter discoverDevicesIntent = new IntentFilter(BluetoothDevice.ACTION_FOUND);
registerReceiver(mBroadcastReceiver3, discoverDevicesIntent);
}
if (!BTAdapter.isDiscovering()){
//checkBTPermissions();
Log.d(TAG,"Searching Now");
BTAdapter.startDiscovery();
Log.d(TAG,"Still Searching Now");
IntentFilter discoverDevicesIntent = new IntentFilter(BluetoothDevice.ACTION_FOUND);
registerReceiver(mBroadcastReceiver3, discoverDevicesIntent);
Log.d(TAG,"123");
}
}
public void backToBT(View view){
Intent intent = new Intent(getApplicationContext(),BTActivity.class);
startActivity(intent);
}
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
//Cancel Discovery as it's costly
BTAdapter.cancelDiscovery();
Log.d(TAG,"onItemClick:Clicked a Device");
String deviceName = mBTDevices.get(i).getName();
String deviceAddress = mBTDevices.get(i).getAddress();
Log.d(TAG,"onItemClick: Device Name: " + deviceName);
Log.d(TAG,"onItemClick: Device Address " + deviceAddress);
//Bonding
if (Build.VERSION.SDK_INT > Build.VERSION_CODES.JELLY_BEAN_MR2){
Log.d(TAG, "Trying to pair with " + deviceName);
mBTDevices.get(i).createBond();
}
}
}
And the manifest is attached
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.ted.pawan462">
<user-feature android:name="android.hardware.bluetooth" />
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.BLUETOOTH_PRIVILEGED" />
<application
android:allowBackup="true"
android:icon="#mipmap/ic_launcher"
android:label="#string/app_name"
android:supportsRtl="true"
android:theme="#style/AppTheme">
<activity android:name=".MainActivity">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".BTActivity" />
<activity android:name=".SearchActivity"></activity>
</application>
</manifest>
This is the Logcat
1-07 21:40:39.633 32744-367/com.example.ted.pawan462 I/Adreno-EGL: <qeglDrvAPI_eglInitialize:379>: EGL 1.4 QUALCOMM build: Nondeterministic_AU_msm8974_LA.BF.1.1.3_RB1__release_AU (Ia6c73e7530)
OpenGL ES Shader Compiler Version: E031.29.00.00
Build Date: 12/04/15 Fri
Local Branch: mybranch17080070
Remote Branch: quic/LA.BF.1.1.3_rb1.5
Local Patches: NONE
Reconstruct Branch: NOTHING
01-07 21:40:39.635 32744-367/com.example.ted.pawan462 I/OpenGLRenderer: Initialized EGL, version 1.4
01-07 21:40:41.786 32744-32744/com.example.ted.pawan462 I/ListPopupWindow: Could not find method setEpicenterBounds(Rect) on PopupWindow. Oh well.
01-07 21:40:41.812 32744-32744/com.example.ted.pawan462 W/art: Before Android 4.1, method int android.support.v7.widget.ListViewCompat.lookForSelectablePosition(int, boolean) would have incorrectly overridden the package-private method in android.widget.ListView
01-07 21:43:54.309 32744-367/com.example.ted.pawan462 D/OpenGLRenderer: endAllStagingAnimators on 0x9db76280 (MenuPopupWindow$MenuDropDownListView) with handle 0x9d2784b0
01-07 21:43:55.320 32744-32744/com.example.ted.pawan462 D/SearchActivity: Looking for unpaired devices
01-07 21:43:55.327 32744-32744/com.example.ted.pawan462 D/AndroidRuntime: Shutting down VM
01-07 21:43:55.329 32744-32744/com.example.ted.pawan462 E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.ted.pawan462, PID: 32744
Theme: themes:{default=overlay:com.wsdeveloper.galaxys7, iconPack:com.wsdeveloper.galaxys7, fontPkg:com.wsdeveloper.galaxys7, com.android.systemui=overlay:com.wsdeveloper.galaxys7, com.android.systemui.navbar=overlay:com.wsdeveloper.galaxys7}
java.lang.IllegalStateException: Could not execute method for android:onClick
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:293)
at android.view.View.performClick(View.java:5204)
at android.view.View$PerformClick.run(View.java:21158)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5461)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288)
at android.view.View.performClick(View.java:5204) 
at android.view.View$PerformClick.run(View.java:21158) 
at android.os.Handler.handleCallback(Handler.java:739) 
at android.os.Handler.dispatchMessage(Handler.java:95) 
at android.os.Looper.loop(Looper.java:148) 
at android.app.ActivityThread.main(ActivityThread.java:5461) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.bluetooth.BluetoothAdapter.isDiscovering()' on a null object reference
at com.example.ted.pawan462.SearchActivity.btnDiscover(SearchActivity.java:58)
at java.lang.reflect.Method.invoke(Native Method) 
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288) 
at android.view.View.performClick(View.java:5204) 
at android.view.View$PerformClick.run(View.java:21158) 
at android.os.Handler.handleCallback(Handler.java:739) 
at android.os.Handler.dispatchMessage(Handler.java:95) 
at android.os.Looper.loop(Looper.java:148) 
at android.app.ActivityThread.main(ActivityThread.java:5461) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 
I think I might have made it worse.

Answer 1

The only thing that stands out to me is you have checkBTPermissions() commented out. But I'm assuming you've tried uncommenting that.
Also make sure that your other devices are set to "discoverable" or the phone won't be able to see them.
Other than that I think it looks pretty good. Maybe something weird going on because your using a menu? Not sure :(.