flashlight - Android camera2 api openCamera error -

i want make simple flashlite application using camera2 api. using following code:

public class flashlightutilforl { private cameracapturesession msession; private capturerequest.builder mbuilder; private cameradevice mcameradevice; private cameramanager mcameramanager;  public flashlightutilforl(context context) {     try {         mcameramanager = (cameramanager) context.getsystemservice(context.camera_service);         //here judge if flash available         cameracharacteristics cameracharacteristics = mcameramanager.getcameracharacteristics("0");         boolean flashavailable = cameracharacteristics.get(cameracharacteristics.flash_info_available);         if (flashavailable) {             mcameramanager.opencamera("0", new mycameradevicestatecallback(), null);         } else {             //todo: throw exception         }         //mcameramanager.opencamera("0", new mycameradevicestatecallback(), null);     } catch (exception e) {         e.printstacktrace();     } }  class mycameradevicestatecallback extends cameradevice.statecallback {      @override     public void onopened(cameradevice camera) {         mcameradevice = camera;         //get builder         try {             mbuilder = camera.createcapturerequest(cameradevice.template_manual);             //flash on, default on             mbuilder.set(capturerequest.control_ae_mode, camerametadata.control_af_mode_auto);             mbuilder.set(capturerequest.flash_mode, camerametadata.flash_mode_torch);             list<surface> list = new arraylist<surface>();             surfacetexture msurfacetexture = new surfacetexture(1);             size size = getsmallestsize(mcameradevice.getid());             msurfacetexture.setdefaultbuffersize(size.getwidth(), size.getheight());             surface msurface = new surface(msurfacetexture);             list.add(msurface);             mbuilder.addtarget(msurface);             camera.createcapturesession(list, new mycameracapturesessionstatecallback(), null);         } catch (cameraaccessexception e) {             e.printstacktrace();         }     }      @override     public void ondisconnected(cameradevice camera) {      }      @override     public void onerror(cameradevice camera, int error) {      } }  private size getsmallestsize(string cameraid) throws cameraaccessexception {     size[] outputsizes = mcameramanager.getcameracharacteristics(cameraid)             .get(cameracharacteristics.scaler_stream_configuration_map)             .getoutputsizes(surfacetexture.class);     if (outputsizes == null || outputsizes.length == 0) {         throw new illegalstateexception(                 "camera " + cameraid + "doesn't support outputsize.");     }     size chosen = outputsizes[0];     (size s : outputsizes) {         if (chosen.getwidth() >= s.getwidth() && chosen.getheight() >= s.getheight()) {             chosen = s;         }     }     return chosen; }  /**  * session callback  */ class mycameracapturesessionstatecallback extends cameracapturesession.statecallback {      @override     public void onconfigured(cameracapturesession session) {         msession = session;         try {             msession.setrepeatingrequest(mbuilder.build(), null, null);         } catch (cameraaccessexception e) {             e.printstacktrace();         }     }      @override     public void onconfigurefailed(cameracapturesession session) {      } }  public void turnonflashlight() {     try {         mbuilder.set(capturerequest.flash_mode, camerametadata.flash_mode_torch);         msession.setrepeatingrequest(mbuilder.build(), null, null);     } catch (exception e) {         e.printstacktrace();     } }  public void turnoffflashlight() {     try {         mbuilder.set(capturerequest.flash_mode, camerametadata.flash_mode_off);         msession.setrepeatingrequest(mbuilder.build(), null, null);     } catch (exception e) {         e.printstacktrace();     } }  private void close() {     if (mcameradevice == null || msession == null) {         return;     }     msession.close();     mcameradevice.close();     mcameradevice = null;     msession = null; } } 

and here how use class main activity:

flashlightutilforl util = new flashlightutilforl(getapplicationcontext()); util.turnonflashlight(); 

but nothing. found there error while opening camera, there no hint on erros caused by. here log:

this printed 3 times in row:

11-10 15:27:32.881 11801-11801/com.flashlight w/arrayutils: ignoring invalid value manual 11-10 15:27:32.881 11801-11801/com.flashlight w/arrayutils: ignoring invalid value fullscan 11-10 15:27:32.881 11801-11801/com.flashlight w/arrayutils: ignoring invalid value nashville 11-10 15:27:32.882 11801-11801/com.flashlight w/arrayutils: ignoring invalid value hefe 11-10 15:27:32.882 11801-11801/com.flashlight w/arrayutils: ignoring invalid value valencia 11-10 15:27:32.882 11801-11801/com.flashlight w/arrayutils: ignoring invalid value xproll 11-10 15:27:32.882 11801-11801/com.flashlight w/arrayutils: ignoring invalid value lofi 11-10 15:27:32.882 11801-11801/com.flashlight w/arrayutils: ignoring invalid value sierra 11-10 15:27:32.882 11801-11801/com.flashlight w/arrayutils: ignoring invalid value walden 11-10 15:27:32.882 11801-11801/com.flashlight w/arrayutils: ignoring invalid value normal 

and once:

11-10 15:27:32.909 11801-11801/com.flashlight i/cameramanager: using legacy camera hal. 11-10 15:27:32.911 11801-12695/com.flashlight w/camera: error occurred while connecting camera: 0 

i not find related particular error in camera2. cause problem? device redmi note 2 5.0.2, camera has flashlight, , have added camera permission in manifest.

i suspect issue cameradevice.template_manual. not devices support this. not think works when device using legacy support. try switching cameradevice.template_preview.

also, not forget release sufacetexture when don it.