Result.Java

package com.example.profile;

import androidx.appcompat.app.AppCompatActivity;
import androidx.drawerlayout.widget.DrawerLayout;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import androidx.annotation.NonNull;

import android.os.Bundle;
import android.view.View;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.EditText;
import android.view.inputmethod.EditorInfo;
import android.util.Log;
import android.text.InputType;

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 java.util.ArrayList;

public class Result extends AppCompatActivity {
    DrawerLayout drawerLayout;
    private static final String TAG = "Result";
    private EditText mNodeNameEditText;
    private DatabaseReference mDatabaseRef;

    private RecyclerView mRecyclerView;
    private RecyclerViewAdapter mAdapter;
    private ArrayList<Pair<String, String>> mData;

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

        drawerLayout = findViewById(R.id.drawer_activity);

        mNodeNameEditText = findViewById(R.id.node_name_edit_text);

        // Set up RecyclerView
        mRecyclerView = findViewById(R.id.recycler_view);
        mRecyclerView.setHasFixedSize(true);
        mRecyclerView.setLayoutManager(new LinearLayoutManager(this));

        mData = new ArrayList<>();
        mAdapter = new RecyclerViewAdapter(Result.this, mData);
        mRecyclerView.setAdapter(mAdapter);

        // Set default node of the database
        mDatabaseRef = FirebaseDatabase.getInstance().getReference("users");

        mNodeNameEditText.setInputType(InputType.TYPE_CLASS_TEXT);
        mNodeNameEditText.setOnEditorActionListener((textView, i, keyEvent) -> {
            if (i == EditorInfo.IME_ACTION_DONE) {
                String nodeName = mNodeNameEditText.getText().toString().trim();
                if (!nodeName.isEmpty()) {
                    retrieveData(nodeName); // Retrieve data for entered node name
                }
                return true;
            }
            return false;
        });
    }


        private void retrieveData(String phoneNumber) {
        DatabaseReference myRef = mDatabaseRef.child(phoneNumber); // Get reference for entered phone number

        myRef.addListenerForSingleValueEvent(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {

                mData.clear(); // Clear the previous data

                // Loop through all child nodes (unique identifiers)
                for (DataSnapshot idSnapshot : dataSnapshot.getChildren()) {
                    // Loop through each child node's content
                    for (DataSnapshot contentSnapshot : idSnapshot.getChildren()) {
                        String name = contentSnapshot.getKey();
                        String data = contentSnapshot.getValue().toString();
                        mData.add(new Pair<>(name, data)); // Add the key-value pair to the data list
                    }
                }

                mAdapter.notifyDataSetChanged(); // Notify the adapter about the data change
            }

            @Override
            public void onCancelled(@NonNull DatabaseError databaseError) {
                Log.w(TAG, "Failed to read value.", databaseError.toException());
            }
        });
    }
}

activity_result.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.drawerlayout.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/drawer_activity"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".Result">


    <androidx.constraintlayout.widget.ConstraintLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <EditText
            android:id="@+id/node_name_edit_text"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_margin="8dp"
            android:hint="Enter node name"
            app:layout_constraintTop_toTopOf="parent" />

        <androidx.recyclerview.widget.RecyclerView
            android:id="@+id/recycler_view"
            android:layout_width="match_parent"
            android:layout_height="0dp"
            android:layout_marginTop="8dp"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintTop_toBottomOf="@+id/node_name_edit_text" />

    </androidx.constraintlayout.widget.ConstraintLayout>

    <RelativeLayout
        android:layout_width="300dp"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        android:background="@color/white">

        <include layout="@layout/main_navigation_drawer" />
    </RelativeLayout>

</androidx.drawerlayout.widget.DrawerLayout>

inputting phonenumber is empty