App crash on android seven -

when run app on android 7 app crashes. android monitor throws :

caused by: android.os.fileuriexposedexception: file:///storage/emulated/0/picture.jpg exposed beyond app through clipdata.item.geturi() 

and code is

   @override         public void onrequestpermissionsresult(int requestcode, @nonnull string[] permissions, @nonnull int[] grantresults) {             super.onrequestpermissionsresult(requestcode, permissions, grantresults);             switch (requestcode) {                 case request_write_permission:                     if (grantresults.length > 0 && grantresults[0] == packagemanager.permission_granted) {                         takepicture();                     } else {                         toast.maketext(mainactivity.this, "permission denied!", toast.length_short).show();                     }             }         }          @override         protected void onactivityresult(int requestcode, int resultcode, intent data) {             if (requestcode == photo_request && resultcode == result_ok) {                 toast.maketext(this,"click on text save data",toast.length_long).show();                 launchmediascanintent();                 try {                     bitmap bitmap = decodebitmapuri(this, imageuri);                     if (detector.isoperational() && bitmap != null) {                         frame frame = new frame.builder().setbitmap(bitmap).build();                         sparsearray<textblock> textblocks = detector.detect(frame);                         string blocks = "";                         string lines = "";                         string words = "";                         (int index = 0; index < textblocks.size(); index++) {                             //extract scanned text blocks here                             textblock tblock = textblocks.valueat(index);                             blocks = blocks + tblock.getvalue() + "\n" + "\n";                             (text line : tblock.getcomponents()) {                                 //extract scanned text lines here                                 lines = lines + line.getvalue() + "\n";                                 (text element : line.getcomponents()) {                                     //extract scanned text words here                                     words = words + element.getvalue() + ", ";                                 }                             }                         }                         if (textblocks.size() == 0) {                              scanresults.settext("scan failed: found nothing scan");                         } else {                             scanresults.settext(scanresults.gettext() +   "\n");                             scanresults.settext(scanresults.gettext() + blocks + "\n");                          }                     } else {                         scanresults.settext("could not set detector!");                     }                 } catch (exception e) {                     toast.maketext(this, "failed load image", toast.length_short)                             .show();                     log.e(log_tag, e.tostring());                 }             }         }          private void takepicture() {             intent intent = new intent(mediastore.action_image_capture);             file photo = new file(environment.getexternalstoragedirectory(), "picture.jpg");             imageuri = uri.fromfile(photo);             intent.putextra(mediastore.extra_output, imageuri);             startactivityforresult(intent, photo_request);             scanresults.settext("");         }          @override         protected void onsaveinstancestate(bundle outstate) {             if (imageuri != null) {                 outstate.putstring(saved_instance_uri, imageuri.tostring());                 outstate.putstring(saved_instance_result, scanresults.gettext().tostring());             }             super.onsaveinstancestate(outstate);         }          private void launchmediascanintent() {             intent mediascanintent = new intent(intent.action_media_scanner_scan_file);             mediascanintent.setdata(imageuri);             this.sendbroadcast(mediascanintent);         }          private bitmap decodebitmapuri(context ctx, uri uri) throws filenotfoundexception {             int targetw = 600;             int targeth = 600;             bitmapfactory.options bmoptions = new bitmapfactory.options();             bmoptions.injustdecodebounds = true;             bitmapfactory.decodestream(ctx.getcontentresolver().openinputstream(uri), null, bmoptions);             int photow = bmoptions.outwidth;             int photoh = bmoptions.outheight;              int scalefactor = math.min(photow / targetw, photoh / targeth);             bmoptions.injustdecodebounds = false;             bmoptions.insamplesize = scalefactor;              return bitmapfactory.decodestream(ctx.getcontentresolver()                     .openinputstream(uri), null, bmoptions);         }          public void store_in_database(view view) {              intent = new intent(mainactivity.this , dbactivity.class);             i.putextra("message",scanresults.gettext().tostring());             mainactivity.this.startactivity(i);           } 

any in form of code great. understand may due file system permissions related android 7 . explanation in form of code welcomed. trying access camera , store image android database.

add code in mainactivity.java in oncreate()

 if (contextcompat.checkselfpermission(googlemapsactivity.this,             android.manifest.permission.read_external_storage)             != packagemanager.permission_granted) {          // should show explanation?         if activitycompat.shouldshowrequestpermissionrationale(googlemapsactivity.this,                 android.manifest.permission.read_external_storage)) {          } else {              activitycompat.requestpermissions(googlemapsactivity.this,                     new string[]{android.manifest.permission.read_external_storage},                     my_permissions_request_read_contacts);          }     }