app keeps crashing when accessing profile tab in my app

Question

so my app keeps crashing, im developing a chat app and when i run the app and try to access the profile tab it crashes the logcat says this.

when it runs the app its fine but as soon as i click profile tab it crashes it was fine at first, but once i added more code to the profile activity it kept crashing however i need that code or a varient of it

im fairly new to android studio all help is welcome.

Thank you

this is the logcat error:

2022-01-25 17:49:08.570 2928-2928/com.example.ttt E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.ttt, PID: 2928
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.ttt/com.example.ttt.ProfileActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ImageButton.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3449)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3601)
    at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85)
    at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135)
    at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2066)
    at android.os.Handler.dispatchMessage(Handler.java:106)
    at android.os.Looper.loop(Looper.java:223)
    at android.app.ActivityThread.main(ActivityThread.java:7656)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)
 Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.ImageButton.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
    at com.example.ttt.ProfileActivity.onCreate(ProfileActivity.java:71)
    at android.app.Activity.performCreate(Activity.java:7994)
    at android.app.Activity.performCreate(Activity.java:7978)
    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1309)
    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3422)
    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3601) 
    at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:85) 
    at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:135) 
    at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:95) 
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2066) 
    at android.os.Handler.dispatchMessage(Handler.java:106) 
    at android.os.Looper.loop(Looper.java:223) 
    at android.app.ActivityThread.main(ActivityThread.java:7656) 
    at java.lang.reflect.Method.invoke(Native Method) 
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947) 

HERE IS THE ProfileActivity:

package com.example.ttt;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

import com.google.android.gms.tasks.OnSuccessListener;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.DataSnapshot;
import com.google.firebase.database.DatabaseError;
 import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.ValueEventListener;
import com.google.firebase.firestore.DocumentReference;
import com.google.firebase.firestore.FirebaseFirestore;
import com.google.firebase.storage.FirebaseStorage;
import com.google.firebase.storage.StorageReference;
import com.squareup.picasso.Picasso;

public class ProfileActivity extends AppCompatActivity {


EditText mviewusername;
FirebaseAuth firebaseAuth;
FirebaseDatabase firebaseDatabase;
TextView mmovetoupdateprofile;

FirebaseFirestore firebaseFirestore;

ImageView mviewuserimageinimageview;

StorageReference storageReference;

private String ImageURIacessToken;

androidx.appcompat.widget.Toolbar mtoolbarofviewprofile;
ImageButton mbackbuttonofviewprofile;


FirebaseStorage firebaseStorage;



@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_profile);

    mviewuserimageinimageview=findViewById(R.id.viewuserimageinview);
    mviewusername=findViewById(R.id.viewusername);
    mmovetoupdateprofile=findViewById(R.id.movetoupdateprofile);
    firebaseFirestore=FirebaseFirestore.getInstance();
    mtoolbarofviewprofile=findViewById(R.id.toolbarofviewprofile);
    mbackbuttonofviewprofile=findViewById(R.id.backbuttonofviewprofile);
    firebaseDatabase=FirebaseDatabase.getInstance();
    firebaseAuth=FirebaseAuth.getInstance();
    firebaseStorage=FirebaseStorage.getInstance();


    setSupportActionBar(mtoolbarofviewprofile);

    mbackbuttonofviewprofile.setOnClickListener(new View.OnClickListener()
    {
        @Override
        public void onClick(View view)
        {
            finish();
        }
    });


    storageReference=firebaseStorage.getReference();
    storageReference.child("Images").child(firebaseAuth.getUid()).child("Profile Pic").getDownloadUrl().addOnSuccessListener(new OnSuccessListener<Uri>() {
        @Override
        public void onSuccess(Uri uri) {
            ImageURIacessToken=uri.toString();
            Picasso.get().load(uri).into(mviewuserimageinimageview);

        }
    });

    DatabaseReference databaseReference=firebaseDatabase.getReference(firebaseAuth.getUid());
    databaseReference.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(@NonNull DataSnapshot snapshot) {
            UserProfile muserprofile=snapshot.getValue(UserProfile.class);
            mviewusername.setText(muserprofile.getUsername());
        }

        @Override
        public void onCancelled(@NonNull DatabaseError error) {

            Toast.makeText(getApplicationContext(),"Failed To Fetch",Toast.LENGTH_SHORT).show();
        }
    });


    mmovetoupdateprofile.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Intent intent=new Intent(ProfileActivity.this,UpdateProfile.class);
            intent.putExtra("nameofuser",mviewusername.getText().toString());
            startActivity(intent);
        }
    });




}


@Override
protected void onStop() {
    super.onStop();
    DocumentReference documentReference=firebaseFirestore.collection("Users").document(firebaseAuth.getUid());
    documentReference.update("status","Offline").addOnSuccessListener(new OnSuccessListener<Void>() {
        @Override
        public void onSuccess(Void aVoid) {
            Toast.makeText(getApplicationContext(),"Now User is Offline",Toast.LENGTH_SHORT).show();
        }
    });



}

@Override
protected void onStart() {
    super.onStart();
    DocumentReference documentReference=firebaseFirestore.collection("Users").document(firebaseAuth.getUid());
    documentReference.update("status","Online").addOnSuccessListener(new OnSuccessListener<Void>() {
        @Override
        public void onSuccess(Void aVoid) {
            Toast.makeText(getApplicationContext(),"Now User is Online",Toast.LENGTH_SHORT).show();
        }
    });

}
}

Answer 1

Here is your problem

TextView mmovetoupdateprofile;

your mmovetoupdateprofile is an ImageButton in your xml and not a Textview