java - Not displaying the "User's Email address" and the data are not stored in the Firebase database -

i have done project firebase user login. when click signup button data not storing in firebase "authetication-users".

it profileactivity.java code

import android.content.intent; import android.support.annotation.nonnull; import android.support.v7.app.appcompatactivity; import android.os.bundle; import android.util.log; import android.view.view; import android.widget.button; import android.widget.textview; import com.google.firebase.auth.firebaseauth; import com.google.firebase.auth.firebaseuser;  public class profileactivity1 extends appcompatactivity implements view.onclicklistener {  private textview textviewemail; private button buttonlogout1;  private firebaseauth mauth;  private firebaseauth.authstatelistener mauthlistener;  private firebaseuser user;  private static final string tag ="firebaseauth";  @override protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.activity_profile1);      mauth = firebaseauth.getinstance();      mauthlistener = new firebaseauth.authstatelistener() {           @override         public void onauthstatechanged(@nonnull firebaseauth firebaseauth) {             firebaseuser user = firebaseauth.getcurrentuser();             if (user != null) {                 // user signed in                 log.d(tag, "welcome your:signed_in:" + user.getemail());             } else {                 // user signed out                 log.d(tag, "onauthstatechanged:signed_out");                                  }          }       };  }   @override public void onclick(view v) {      if(v == buttonlogout1) {         mauth.signout();         intent intent = new intent(profileactivity1.this, mainactivity.class);         startactivity(intent);         finish();     }  } } 

what going wrong here?

why failing save data?

please let me know.

sorry bad formatting of question. i'm still beginner.

in offical documentation, you'll find need implement firebase authentication. explained step step whole process. follow steps in exact way explained there , done sure.

for specific example, can use this tutorial.