Fix NPE when bluetooth is off per #107

AltBeacon · Feb 4, 2015 · 1b19c2b · 1b19c2b
1 parent c2ad29e
commit 1b19c2b
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Showing 2 changed files with 37 additions and 13 deletions.
diff --git a/src/main/java/org/altbeacon/beacon/service/scanner/CycledLeScanner.java b/src/main/java/org/altbeacon/beacon/service/scanner/CycledLeScanner.java
@@ -274,6 +274,9 @@ protected BluetoothAdapter getBluetoothAdapter() {
             final BluetoothManager bluetoothManager =
                     (BluetoothManager) mContext.getApplicationContext().getSystemService(Context.BLUETOOTH_SERVICE);
             mBluetoothAdapter = bluetoothManager.getAdapter();
+            if (mBluetoothAdapter == null) {
+                LogManager.w(TAG, "Failed to construct a BluetoothAdapter");
+            }
         }
         return mBluetoothAdapter;
     }

diff --git a/src/main/java/org/altbeacon/beacon/service/scanner/CycledLeScannerForLollipop.java b/src/main/java/org/altbeacon/beacon/service/scanner/CycledLeScannerForLollipop.java
@@ -35,7 +35,9 @@ public CycledLeScannerForLollipop(Context context, long scanPeriod, long between
     @Override
     protected void stopScan() {
         try {
-            mScanner.stopScan(getNewLeScanCallback());
+            if (getScanner() != null) {
+                getScanner().stopScan(getNewLeScanCallback());
+            }
         }
         catch (Exception e) {
             LogManager.w(e, TAG, "Internal Android exception scanning for beacons");
@@ -94,8 +96,10 @@ protected boolean deferScanIfNeeded() {
                         ScanSettings settings = (new ScanSettings.Builder().setScanMode(ScanSettings.SCAN_MODE_LOW_POWER)).build();
 
                         try {
-                        mScanner.startScan(new ScanFilterUtils().createScanFiltersForBeaconParsers(
-                                mBeaconManager.getBeaconParsers()), settings, getNewLeScanCallback());
+                            if (getScanner() != null) {
+                                getScanner().startScan(new ScanFilterUtils().createScanFiltersForBeaconParsers(
+                                        mBeaconManager.getBeaconParsers()), settings, getNewLeScanCallback());
+                            }
                         }
                         catch (IllegalStateException e) {
                             LogManager.w(TAG, "Cannot start scan.  Bluetooth may be turned off.");
@@ -120,7 +124,9 @@ protected boolean deferScanIfNeeded() {
                             // so we do not drain battery
                             LogManager.d(TAG, "We've been detecting for a bit.  Stopping Android L background scanning");
                             try {
-                                mScanner.stopScan((android.bluetooth.le.ScanCallback) getNewLeScanCallback());
+                                if (getScanner() != null) {
+                                    getScanner().stopScan((android.bluetooth.le.ScanCallback) getNewLeScanCallback());
+                                }
                             }
                             catch (IllegalStateException e) {
                                 LogManager.w(TAG, "Cannot stop scan.  Bluetooth may be turned off.");
@@ -155,28 +161,28 @@ public void run() {
         else {
             if (mBackgroundLScanStartTime > 0l) {
                 try {
-                    mScanner.stopScan((android.bluetooth.le.ScanCallback) getNewLeScanCallback());
+                    if (getScanner() != null) {
+                        getScanner().stopScan((android.bluetooth.le.ScanCallback) getNewLeScanCallback());
+                    }
                 }
                 catch (IllegalStateException e) {
                     LogManager.w(TAG, "Cannot stop scan.  Bluetooth may be turned off.");
                 }
 
-                mScanner.stopScan(getNewLeScanCallback());
+                if (getScanner() != null) {
+                    getScanner().stopScan(getNewLeScanCallback());
+                }
+
                 mBackgroundLScanStartTime = 0;
             }
             mScanDeferredBefore = false;
         }
         return false;
     }
 
-
     @Override
     protected void startScan() {
         List<ScanFilter> filters = new ArrayList<ScanFilter>();
-        if (mScanner == null) {
-            LogManager.d(TAG, "Making new Android L scanner");
-            mScanner = getBluetoothAdapter().getBluetoothLeScanner();
-        }
         ScanSettings settings;
 
         if (mBackgroundFlag) {
@@ -188,7 +194,9 @@ protected void startScan() {
 
         }
         try {
-            mScanner.startScan(filters, settings, getNewLeScanCallback());
+            if (getScanner() != null) {
+                getScanner().startScan(filters, settings, getNewLeScanCallback());
+            }
         }
         catch (IllegalStateException e) {
             LogManager.w(TAG, "Cannot start scan.  Bluetooth may be turned off.");
@@ -198,7 +206,9 @@ protected void startScan() {
     @Override
     protected void finishScan() {
         try {
-            mScanner.stopScan(getNewLeScanCallback());
+            if (getScanner() != null) {
+                getScanner().stopScan(getNewLeScanCallback());
+            }
         }
         catch (IllegalStateException e) {
             LogManager.w(TAG, "Cannot stop scan.  Bluetooth may be turned off.");
@@ -207,6 +217,17 @@ protected void finishScan() {
         mScanningPaused = true;
     }
 
+    private BluetoothLeScanner getScanner() {
+        if (mScanner == null) {
+            LogManager.d(TAG, "Making new Android L scanner");
+            mScanner = getBluetoothAdapter().getBluetoothLeScanner();
+            if (mScanner == null) {
+                LogManager.w(TAG, "Failed to make new Android L scanner");
+            }
+        }
+        return mScanner;
+    }
+
     private ScanCallback getNewLeScanCallback() {
         if (leScanCallback == null) {
             leScanCallback = new ScanCallback() {