// Application hold only one OBContext instance.
private OBContext mOBContext;
private Object mCurrentDeviceLock = new Object();
private Device mCurrentDevice;
private DeviceInfo mCurrentDeviceInfo;

mOBContext = new OBContext(getApplicationContext(), new DeviceChangedCallback() {
   @Override
   public void onDeviceAttach(DeviceList deviceList) {
        try {
            mCurrentDevice = deviceList.getDevice(0);
            mCurrentDeviceInfo = mCurrentDevice.getInfo();
            deviceList.close();
            // do something
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            deviceList.close();
        }
   }

   @Override
   public void onDeviceDetach(DeviceList deviceList) {
         try {
            if (null != mCurrentDevice){
                int deviceCount = deviceList.getDeviceCount();
                    for(int i = 0; i < deviceCount; i++){
                        String uid = deviceList.getUid();
                        if(null != mCurrentDeviceInfo && mCurrentDeviceInfo.getUid().equals(uid)){
                            // handle device disconnection
                            // do something

                            Log.d("Orbbec","Device disconnection. name: "+mCurrentDeviceInfo.getName()+", uid: "+mCurrentDeviceInfo.getUid());
                            mCurrentDevice.close();
                            mCurrentDevice=null;
                        }
                    }
            }
         } catch (Exception e) {
            e.printStackTrace();
         } finally {
            deviceList.close();
        }
   }
});

private Pipeline mPipeline;

try {
   mPipeline = new Pipeline(mCurrentDevice);

   StreamProfileList depthProfileList = mPipeline.getStreamProfileList(SensorType.DEPTH);
   if (null == depthProfileList) {
      return;
   }
   StreamProfile streamProfile = depthProfileList.getStreamProfile(0);
   Config config = new Config();
   config.enableStream(streamProfile);
   streamProfile.close();
   depthProfileList.close();

   mPipeline.start(config, new FrameSetCallback() {
      public void onFrameSet(FrameSet frameSet) {
         DepthFrame depthFrame = frameSet.getDepthFrame()
         if (null != depthFrame) {
            Log.d("Orbbec", "onFrameSet depthFrame index: " + depthFrame.getFrameIndex() + ", timeStamp: " + depthFrame.getTimeStamp());

            // do Render

            depthFrame.close();
         }
      }
   });
   config.close();
} catch (OBException e) {
   e.printStackTrace();
}

try {
   mPipeline.stop();
} catch (OBException e) {
   e.printStackTrace();
}

try {
   if (null != mPipeline) {
      mPipeline.close();
   }

   if (mDevice != null) {
      mDevice.close();
   }
} catch (OBException e) {
   e.printStackTrace();
}