Error Null Object

Question

I’m developing an app delivery (with client version and Adm) in which the administrator version changes the status of orders through a spinner, after which the client app receives a status update. The problem is that when I change the status the error occurs below:

Log Cat

04-03 15:17:55.920 22138-22138/com.vsousa.burgaoadm E/UncaughtException: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.vsousa.burgaoadm/com.vsousa.burgaoadm.Home}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String com.vsousa.burgaoadm.Model.User.getName()' on a null object reference
                                                                             at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2416)
                                                                             at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476)
                                                                             at android.app.ActivityThread.-wrap11(ActivityThread.java)
                                                                             at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344)
                                                                             at android.os.Handler.dispatchMessage(Handler.java:102)
                                                                             at android.os.Looper.loop(Looper.java:148)
                                                                             at android.app.ActivityThread.main(ActivityThread.java:5417)
                                                                             at java.lang.reflect.Method.invoke(Native Method)
                                                                             at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
                                                                             at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
                                                                          Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String com.vsousa.burgaoadm.Model.User.getName()' on a null object reference
                                                                             at com.vsousa.burgaoadm.Home.onCreate(Home.java:121)
                                                                             at android.app.Activity.performCreate(Activity.java:6237)
                                                                             at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107)
                                                                             at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369)

Home.class:

package com.vsousa.burgaoadm;

import android.app.ProgressDialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AlertDialog;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.support.design.widget.NavigationView;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;

import com.firebase.ui.database.FirebaseRecyclerAdapter;
import com.google.android.gms.tasks.OnFailureListener;
import com.google.android.gms.tasks.OnSuccessListener;
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.Query;
import com.google.firebase.database.ValueEventListener;
import com.google.firebase.iid.FirebaseInstanceId;
import com.google.firebase.storage.FirebaseStorage;
import com.google.firebase.storage.OnProgressListener;
import com.google.firebase.storage.StorageReference;
import com.google.firebase.storage.UploadTask;
import com.rengwuxian.materialedittext.MaterialEditText;
import com.squareup.picasso.Picasso;
import com.vsousa.burgaoadm.Common.Common;
import com.vsousa.burgaoadm.Interface.ItemClickListener;
import com.vsousa.burgaoadm.Model.Category;
import com.vsousa.burgaoadm.Model.Token;
import com.vsousa.burgaoadm.ViewHolder.MenuViewHolder;

import java.util.UUID;

public class Home extends AppCompatActivity
        implements NavigationView.OnNavigationItemSelectedListener {

    TextView txtFullName;

    FirebaseDatabase database;
    DatabaseReference categories;
    FirebaseStorage storage;
    StorageReference storageReference;
    FirebaseRecyclerAdapter<Category, MenuViewHolder> adapter;

    RecyclerView recycler_menu;
    RecyclerView.LayoutManager layoutManager;

    MaterialEditText edtName;
    Button btnUpload, btnSelect;

    Category newCategory;

    Uri saveUri;

    DrawerLayout drawer;

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

        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        toolbar.setTitle("Menu Adm");
        setSupportActionBar(toolbar);


        //Iniciar Firebase
        database = FirebaseDatabase.getInstance();
        categories = database.getReference("Category");
        storage = FirebaseStorage.getInstance();
        storageReference = storage.getReference();


        FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                showDialog();
            }
        });


       drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(
                this, drawer, toolbar, R.string.navigation_drawer_open, R.string.navigation_drawer_close);
        drawer.addDrawerListener(toggle);
        toggle.syncState();

        NavigationView navigationView = (NavigationView) findViewById(R.id.nav_view);
        navigationView.setNavigationItemSelectedListener(this);


        //Setando nome do usuário

        View headerView = navigationView.getHeaderView(0);
        txtFullName = headerView.findViewById(R.id.txtFullName);
        txtFullName.setText(Common.currentUser.getName());


        //Iniciar Visualização
        recycler_menu = findViewById(R.id.recycler_menu);
        recycler_menu.setHasFixedSize(true);
        layoutManager = new LinearLayoutManager(this);
        recycler_menu.setLayoutManager(layoutManager);

        loadMenu();

        //Enviando Token
        updateToken(FirebaseInstanceId.getInstance().getToken());

    }

    private void updateToken(String token) {
        FirebaseDatabase db = FirebaseDatabase.getInstance();
        DatabaseReference tokens = db.getReference("Tokens");
        Token data = new Token(token, true);
        tokens.child(Common.currentUser.getPhone()).setValue(data);

    }

    private void showDialog() {
        AlertDialog.Builder alertDialog = new AlertDialog.Builder(Home.this);
        alertDialog.setTitle("Adicionar nova categoria");
        alertDialog.setMessage("Preencha todas as informações!");

        LayoutInflater inflater = this.getLayoutInflater();
        View add_menu_layout = inflater.inflate(R.layout.add_new_menu_layout, null);

        edtName = add_menu_layout.findViewById(R.id.edtName);
        btnSelect = add_menu_layout.findViewById(R.id.btnSelect);
        btnUpload = add_menu_layout.findViewById(R.id.btnUpload);

             //Evento do Botão
        btnSelect.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                chooseImage();     //Para selecionar imagens da galeria
            }
        });

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

        alertDialog.setView(add_menu_layout);
        alertDialog.setIcon(R.drawable.ic_playlist_add_black_24dp);

        //Setando botão
        alertDialog.setPositiveButton("OK", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialogInterface, int i) {

                dialogInterface.dismiss();

                //Aqui, apenas cria uma nova categoria
                if (newCategory != null)
                {

                    categories.push().setValue(newCategory);
                    Snackbar.make(drawer, "Nova categoria "+newCategory.getName()+" foi adicionada!", Snackbar.LENGTH_SHORT).show();
                }
             }
        });

        alertDialog.setNegativeButton("Cancelar", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialogInterface, int i) {
                dialogInterface.dismiss();
                Toast.makeText(Home.this, "Processo cancelado", Toast.LENGTH_SHORT).show();

            }
        });

        alertDialog.show();

    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == Common.PICK_IMAGE_REQUEST && resultCode == RESULT_OK && data != null && data.getData() != null)
        {
            saveUri = data.getData();
            btnSelect.setText("Imagem Carregada");  //Mostra mensagem após a imagem ser escolhida
        }
    }

    //SELECIONAR IMAGEM
    private void chooseImage() {
        Intent intent = new Intent();
        intent.setType("image/*");
        intent.setAction(Intent.ACTION_GET_CONTENT);
        startActivityForResult(Intent.createChooser(intent, "Selecione imagem"), Common.PICK_IMAGE_REQUEST);
    }

    //CARREGANDO IMAGEM
    private void uploadImage() {
        if (saveUri != null)
        {
            final ProgressDialog mDialog = new ProgressDialog(this);
            mDialog.setMessage("Carregando...");
            mDialog.show();

            String imageName = UUID.randomUUID().toString();
            final StorageReference imageFolder = storageReference.child("images/"+imageName);
            imageFolder.putFile(saveUri)
                    .addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
                        @Override
                        public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
                            mDialog.dismiss();
                            Toast.makeText(Home.this, "Finalizado!", Toast.LENGTH_SHORT).show();
                                imageFolder.getDownloadUrl().addOnSuccessListener(new OnSuccessListener<Uri>() {
                                @Override
                                public void onSuccess(Uri uri) {

                                    //Setando valores na nova categoria
                                    newCategory = new Category(edtName.getText().toString(), uri.toString());

                                }
                            });
                          }
                    })

                    .addOnFailureListener(new OnFailureListener() {
                        @Override
                        public void onFailure(@NonNull Exception e) {
                            mDialog.dismiss();
                            Toast.makeText(Home.this, ""+e.getMessage(), Toast.LENGTH_SHORT).show();
                        }
                    })

                    .addOnProgressListener(new OnProgressListener<UploadTask.TaskSnapshot>() {
                        @Override
                        public void onProgress(UploadTask.TaskSnapshot taskSnapshot) {
                            double progress = (100 * taskSnapshot.getBytesTransferred() / taskSnapshot.getTotalByteCount());
                            mDialog.setMessage("Carregando "+progress+"%");

                        }
                    });
        }

    }

    private void loadMenu() {
        adapter = new FirebaseRecyclerAdapter<Category, MenuViewHolder>(
                Category.class,
                R.layout.menu_item,
                MenuViewHolder.class,
                categories
        ) {
            @Override
            protected void populateViewHolder(MenuViewHolder viewHolder, Category model, int position) {
              viewHolder.txtMenuName.setText(model.getName());
              Picasso.with(Home.this).load(model.getImage())
                      .into(viewHolder.imageView);

              viewHolder.setItemClickListener(new ItemClickListener() {
                  @Override
                  public void onClick(View view, int position, boolean isLongClick) {
                      //Abir nova tela de acordo com a categoria
                      Intent foodList = new Intent(Home.this, FoodList.class);
                      foodList.putExtra("CategoryId", adapter.getRef(position).getKey());
                      startActivity(foodList);

                  }
              });

            }
        };

        //Atualizar dados se houver mudanças
        adapter.notifyDataSetChanged();
        recycler_menu.setAdapter(adapter);
    }

    @Override
    public void onBackPressed() {
        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        if (drawer.isDrawerOpen(GravityCompat.START)) {
            drawer.closeDrawer(GravityCompat.START);
        } else {
            super.onBackPressed();
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.home, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }

        return super.onOptionsItemSelected(item);
    }

    @SuppressWarnings("StatementWithEmptyBody")
    @Override
    public boolean onNavigationItemSelected(MenuItem item) {
        // Handle navigation view item clicks here.
        int id = item.getItemId();

        if (id == R.id.nav_menu) {

        } else if (id == R.id.nav_orders) {
            Intent OrderIntent = new Intent(Home.this, OrderStatus.class);
            startActivity(OrderIntent);

     /*   } else if (id == R.id.nav_cart) {
            Intent cartIntent = new Intent(Home.this, Cart.class);
            startActivity(cartIntent);

        } else if (id == R.id.nav_sobre) {  */

        } else if (id == R.id.nav_sair) {
            Intent signIn = new Intent(Home.this, SignIn.class);
            signIn.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK | Intent.FLAG_ACTIVITY_CLEAR_TASK);
            startActivity(signIn);

    /*    } else if (id == R.id.nav_contato) {
            Intent contato = new Intent(Home.this, Contato.class);
            startActivity(contato);

        } else if (id == R.id.nav_endereco) {
            Intent endereco = new Intent(Home.this, Endereco.class);
            startActivity(endereco);

        } else if (id == R.id.nav_app) {
            Intent info = new Intent(Home.this, Info.class);
            startActivity(info);   */

        }

        DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        drawer.closeDrawer(GravityCompat.START);
        return true;
    }

        //Setar nome default
        edtName.setText(item.getName());




        alertDialog.show();
    }



    private void changeImage(final Category item) {
        if (saveUri != null)
        {
            final ProgressDialog mDialog = new ProgressDialog(this);
            mDialog.setMessage("Carregando...");
            mDialog.show();

            String imageName = UUID.randomUUID().toString();
            final StorageReference imageFolder = storageReference.child("images/"+imageName);
            imageFolder.putFile(saveUri)
                    .addOnSuccessListener(new OnSuccessListener<UploadTask.TaskSnapshot>() {
                        @Override
                        public void onSuccess(UploadTask.TaskSnapshot taskSnapshot) {
                            mDialog.dismiss();
                            Toast.makeText(Home.this, "Finalizado!", Toast.LENGTH_SHORT).show();

                            imageFolder.getDownloadUrl().addOnSuccessListener(new OnSuccessListener<Uri>() {
                                @Override
                                public void onSuccess(Uri uri) {

                                    //Setando valores na nova categoria
                                    item.setImage(uri.toString());

                                }
                            });

                        }
                    })

                    .addOnFailureListener(new OnFailureListener() {
                        @Override
                        public void onFailure(@NonNull Exception e) {
                            mDialog.dismiss();
                            Toast.makeText(Home.this, ""+e.getMessage(), Toast.LENGTH_SHORT).show();

                        }
                    })

                    .addOnProgressListener(new OnProgressListener<UploadTask.TaskSnapshot>() {
                        @Override
                        public void onProgress(UploadTask.TaskSnapshot taskSnapshot) {
                            double progress = (100 * taskSnapshot.getBytesTransferred() / taskSnapshot.getTotalByteCount());
                            mDialog.setMessage("Carregando "+progress+"%");

                        }
                    });
        }

    }
}

Common.class:

package com.vsousa.burgaoadm.Common;

import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;

import com.vsousa.burgaoadm.Model.Request;
import com.vsousa.burgaoadm.Model.User;
import com.vsousa.burgaoadm.Remote.APIService;
import com.vsousa.burgaoadm.Remote.FCMRetrofitClient;
import com.vsousa.burgaoadm.Remote.IGeoCoordinates;
import com.vsousa.burgaoadm.Remote.RetrofitClient;

/**
 * Created by valdemir.sousa on 15/02/2018.
 */

public class Common {
    public static User currentUser;
    public static Request currentRequest;


    public static final String UPDATE = "Alterar";
    public static final String DELETE = "Remover";

    public static final int PICK_IMAGE_REQUEST = 71;

    public static final String baseUrl = "https://maps.googleapis.com";

    public static final String fcmUrl = "https://fcm.googleapis.com/";

    public static String convertCodeToStatus (String code)
    {
        switch (code) {
            case "0":
                return "Pedido recebido";
            case "1":
                return "Pedido em preparação";
            case "2":
                return "Pedido a caminho";
            case "3":
                return "Pedido entregue";
            default:
                return "Pedido recebido";
        }
    }

    public static APIService getFCMClient(){
        return FCMRetrofitClient.getClient(fcmUrl).create(APIService.class);
    }

    public static IGeoCoordinates getGeoCodeService(){
        return RetrofitClient.getClient(baseUrl).create(IGeoCoordinates.class);
    }

    public static Bitmap scaleBitmap(Bitmap bitmap, int newWidth, int newHeight)
    {
        Bitmap scaleBitmap = Bitmap.createBitmap(newWidth, newHeight, Bitmap.Config.ARGB_8888);

        float scaleX = newWidth/ (float)bitmap.getWidth();
        float scaleY = newHeight/ (float)bitmap.getHeight();
        float pivotX = 0, pivotY = 0;

        Matrix scaleMatrix = new Matrix();
        scaleMatrix.setScale(scaleX, scaleY, pivotX, pivotY);

        Canvas canvas = new Canvas(scaleBitmap);
        canvas.setMatrix(scaleMatrix);
        canvas.drawBitmap(bitmap, 0, 0, new Paint(Paint.FILTER_BITMAP_FLAG));

        return scaleBitmap;
    }
}