java - NullPointerException for getApplicationContext() in Delegate Class -


i have second class call methods handle app updating. there progress dialog in them have pass current application context constructor. code works fine when called directly in mainactivity oncreate(), breaks down when delegate code external class. what's going wrong?

method call in oncreate():

private appupdatehelper appupdatehelper = new appupdatehelper(getapplicationcontext());  @override     protected void oncreate(bundle savedinstancestate) {     appupdatehelper.handleappupdate();     }

delegate class:

public class appupdatehelper {      private context mcontext;      public appupdatehelper(context mcontext) {         this.mcontext = mcontext;     }      public void handleappupdate() {         string versioncode = getversioncode(); // app's current version code          // app update date?         if (isappcurrent(versioncode)) {             promptappupdate();         }     }       private string getversioncode() {         string versioncode = null;         try {             packageinfo pinfo = mcontext.getpackagemanager().getpackageinfo(mcontext.getpackagename(), 0);             versioncode = pinfo.versionname;             // log.w(mcontext.getclass().getsimplename(), "current version: " + versioncode);         } catch (packagemanager.namenotfoundexception e) {             e.printstacktrace();         }         return versioncode;     }       private boolean isappcurrent(string versioncode) {         parseinstallation installation = parseinstallation.getcurrentinstallation();         string userappversion = installation.getstring("appversion");         return !userappversion.equals(versioncode);     }       private void promptappupdate() {         sweetalertdialog pdialog = new sweetalertdialog(mcontext, sweetalertdialog.warning_type);         pdialog.settitletext("update available!");         pdialog.setcontenttext("you must update continue using yeet club!");         pdialog.setconfirmclicklistener(sdialog -> {             final string apppackagename = mcontext.getpackagename(); // getpackagename() context or activity object             try {                 mcontext.startactivity(new intent(intent.action_view, uri.parse("market://details?id=" + apppackagename)));             } catch (activitynotfoundexception anfe) {                 mcontext.startactivity(new intent(intent.action_view, uri.parse("https://play.google.com/store/apps/details?id=" + apppackagename)));             }              sdialog.dismisswithanimation();         });         pdialog.setcancelable(false);         pdialog.showcancelbutton(false);         pdialog.show();     }  }

exception:

08 - 20 15: 43: 43.874 21456 - 21456 / com.app.android e / androidruntime: fatal exception: main process: com.app.android, pid: 21456 java.lang.runtimeexception: unable instantiate activity componentinfo {  com.app.android / com.app.android.activity.mainactivity }: java.lang.nullpointerexception: attempt invoke virtual method 'android.content.context android.content.context.getapplicationcontext()' on null object reference @ android.app.activitythread.performlaunchactivity(activitythread.java: 2458) @ android.app.activitythread.handlelaunchactivity(activitythread.java: 2613) @ android.app.activitythread.access$900(activitythread.java: 180) @ android.app.activitythread$h.handlemessage(activitythread.java: 1473) @ android.os.handler.dispatchmessage(handler.java: 111) @ android.os.looper.loop(looper.java: 207) @ android.app.activitythread.main(activitythread.java: 5710) @ java.lang.reflect.method.invoke(native method) @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java: 900) @ com.android.internal.os.zygoteinit.main(zygoteinit.java: 761) caused by: java.lang.nullpointerexception: attempt invoke virtual method 'android.content.context android.content.context.getapplicationcontext()' on null object reference @ android.content.contextwrapper.getapplicationcontext(contextwrapper.java: 117) @ com.app.android.activity.mainactivity. < init > (mainactivity.java: 77) @ java.lang.class.newinstance(native method) @ android.app.instrumentation.newactivity(instrumentation.java: 1072) @ android.app.activitythread.performlaunchactivity(activitythread.java: 2448) @ android.app.activitythread.handlelaunchactivity(activitythread.java: 2613)  @ android.app.activitythread.access$900(activitythread.java: 180)  @ android.app.activitythread$h.handlemessage(activitythread.java: 1473)  @ android.os.handler.dispatchmessage(handler.java: 111)  @ android.os.looper.loop(looper.java: 207)  @ android.app.activitythread.main(activitythread.java: 5710)  @ java.lang.reflect.method.invoke(native method)  @ com.android.internal.os.zygoteinit$methodandargscaller.run(zygoteinit.java: 900)  @ com.android.internal.os.zygoteinit.main(zygoteinit.java: 761) 

this simple.

you can context instance after called oncreate

private appupdatehelper appupdatehelper;  @override      protected void oncreate(bundle savedinstancestate) {      appupdatehelper = new appupdatehelper(getapplicationcontext());      appupdatehelper.handleappupdate();     }

Comments

Post a Comment

Popular posts from this blog

ubuntu - PHP script to find files of certain extensions in a directory, returns populated array when run in browser, but empty array when run from terminal -

i running os ububtu 16.04. ultimate goal able run php script cron job every minute. here php script located @ /var/www/html/tests/test/index.php : <?php $directorypath = $_server['document_root']."/tests/test/data/"; echo "directorypath: $directorypath<br><br>";//check $imagefilepathsarray = glob($directorypath . "*.{png,gif}", glob_brace); echo "<br><br>imagefilepathsarray: "; print_r($imagefilepathsarray);//check ?> when open php script in browser visiting url my-ip-address/tests/test/index.php , get: directorypath: /var/www/html/tests/test/data/ imagefilepathsarray:array( [0] => /var/www/html/tests/test/data/pic.png [1] => /var/www/html/tests/test/data/pic.gif ) before writing cron job in crontab file, need check if can run anywhere using terminal . opened ubuntu terminal @ /home/ location, , executed in terminal: sudo php /var/www/html/tests/test/index.php i got following out...
Read more

php - How can i create a user dashboard -

today have questions you, want create user dashboard site, include (obviously), users data, example -email -username -and others stuff how can information, , print them in html page? if can, how can these information via php sessions? shuld use session? example, if user login, , start new session ( session_start() ), how can data print in dashboard? should use php "project"? in advice, have day , thank time!
Read more

javascript - How to detect toggling of the fullscreen-toolbar in jQuery Mobile? -

i have jquery mobile page fixed full-screen toolbar, data-tap-toggle enabled. straight under toolbar have positioned banner should slide upwards when toolbar hiding , slide downward when toolbar showing. jquery mobile toggles toolbar applying , removing ui-fixed-hidden class - sadly, can't find in documentation of toolbar widget toggle , hide or show event that. how can detect when toolbar toggled, reposition banner? .banner { position: fixed; background-color: darkseagreen; top: 46px; min-height: 48px; width: 100%; text-align: center; line-height: 48px; } <!doctype html> <html> <head> <meta charset="utf-8"> <meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=no"> <link rel="stylesheet" href="https://code.jquery.com/mobile/1.4.5/jquery.mobile-1.4.5.css"> <script src="https://code.jquery.com/jquery-1....
Read more