Merge pull request #318 from yoviep/ISSUE_284

Fix issue #284

Author: DantSu

escposprinter/src/main/java/com/dantsu/escposprinter/connection/bluetooth/BluetoothConnection.java

@@ -60,8 +60,8 @@ public BluetoothConnection connect() throws EscPosConnectionException {
         }
 
         BluetoothAdapter bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
-        ParcelUuid[] uuids = this.device.getUuids();
-        UUID uuid = (uuids != null && uuids.length > 0) ? uuids[0].getUuid() : UUID.randomUUID();
+
+        UUID uuid = this.getDeviceUUID();
 
         try {
             this.socket = this.device.createRfcommSocketToServiceRecord(uuid);
@@ -77,6 +77,15 @@ public BluetoothConnection connect() throws EscPosConnectionException {
         return this;
     }
 
+    /**
+     * Get bluetooth device UUID
+     */
+    protected UUID getDeviceUUID() {
+        // https://developer.android.com/reference/android/bluetooth/BluetoothDevice - "00001101-0000-1000-8000-00805f9b34fb" SPP UUID
+        ParcelUuid[] uuids = device.getUuids();
+        return (uuids != null && uuids.length > 0) ? uuids[0].getUuid() : UUID.fromString("00001101-0000-1000-8000-00805f9b34fb");
+    }
+
     /**
      * Close the socket connection with the bluetooth device.
      */