android - public static variable has the value , but when i try to show it to textview(in another class) it has no value -

my activity flow , login page->mainpage(in have button go userprofile has onclick method)-> button onclick method "startactivity(userprofile)" have onclick method loads activity userprofile. want load details of user, have static variables no luck.

public class userprofile extends appcompatactivity {     textview textview , textview1 , textview2 ;     context context_userprofile;     @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_userprofile);         toolbar toolbar = (toolbar) findviewbyid(r.id.toolbar);         setsupportactionbar(toolbar);         func_userprofile_show();     }      public void func_userprofile_show(){         string type = "linkuser";         databaselink databaselink = new databaselink(this);         databaselink.execute(type);         context_userprofile = getapplicationcontext();         textview = (textview)findviewbyid(r.id.tvprofilepage_user);         assert textview != null;         textview.settext(databaselink.thename);         textview1 = (textview)findviewbyid(r.id.tvprofilepage_ign);         assert textview1 != null;         textview1.settext(databaselink.theign);         textview2 = (textview)findviewbyid(r.id.tvprofilepage_emailid);         assert textview2 != null;         textview2.settext(databaselink.theemail);     } } 

now method diffrent class extends asynctask , "theign" showing in alertdialog not in textview.

public void decodejson() {     try {         jsonobject jsonobj = new jsonobject(myjson);         details_json = jsonobj.getjsonarray(tag_results);          (int = 0; < details_json.length(); i++) {             jsonobject c = details_json.getjsonobject(i);             thename = c.getstring(tag_name);             theign= c.getstring(tag_ign);             theemail = c.getstring(tag_email);         }     } catch (jsonexception e) {         e.printstacktrace();     } }  @override protected void onpreexecute() {     alertdialog = new alertdialog.builder(context).create();     alertdialog.settitle("user profile loading..."); }  @override protected void onpostexecute(string result) {     myjson = result;     decodejson();     alertdialog.setmessage(theign);     alertdialog.show(); } 

the problem textview.settext called before asynctask has finished.

to solve problem can implement interface call function inside activity when info ready. assuming asynktask inside databaselink class, sow pseudocode..

interface:

public interface databaselinkinterface {     public void databaselinkfinished(); } 

the context listener. have context in databaselink class:

@override protected void onpostexecute(string result) {     myjson = result;     decodejson();     alertdialog.setmessage(theign);     alertdialog.show();     databaselinkinterface mlistener = (databaselinkinterface) context;     mlistener.databaselinkfinished(); } 

implement interface in activity , create databaselink in oncreate:

public class userprofile extends appcompatactivity implements databaselinkinterface {     textview textview , textview1 , textview2 ;     context context_userprofile;     databaselink databaselink;     @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_userprofile);         toolbar toolbar = (toolbar) findviewbyid(r.id.toolbar);         setsupportactionbar(toolbar);         string type = "linkuser";         databaselink = new databaselink(this);         databaselink.execute(type);     }      ... 

and finally, in activity, implements interface method know when data fetched. remove func_userprofile_show(). avoid use static variables purpose.

@override  public void databaselinkfinished(){     context_userprofile = getapplicationcontext();     textview = (textview)findviewbyid(r.id.tvprofilepage_user);     assert textview != null;     textview.settext(databaselink.thename);     textview1 = (textview)findviewbyid(r.id.tvprofilepage_ign);     assert textview1 != null;     textview1.settext(databaselink.theign);     textview2 = (textview)findviewbyid(r.id.tvprofilepage_emailid);     assert textview2 != null;     textview2.settext(databaselink.theemail); } 

i recommend use getters , setters instead of access directly attribute (databaselink.theemail -> databaselink.gettheemail())