Java Android application quickly closes after opening

Question

A while ago, i had the main login/signup screen and the drawer working, but when i tried to implement a item database, which class while implemented i did not instantiate or call anywhere, still the app stopped working, it would open and quickly close, the mobile would report that "The app was presenting continuous failures" even without changing the business rules or model.

This my launch activity the MainActivity which is the SignIn

package com.example.appteste;

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

import android.content.Intent;
import android.graphics.Color;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageButton;
import android.widget.Toast;

import com.example.appteste.ui.login.LoginActivity;
import com.github.mikephil.charting.charts.PieChart;
import com.github.mikephil.charting.data.PieData;
import com.github.mikephil.charting.data.PieDataSet;
import com.github.mikephil.charting.data.PieEntry;
import com.github.mikephil.charting.utils.ColorTemplate;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.auth.UserProfileChangeRequest;

import java.util.ArrayList;

import lecho.lib.hellocharts.model.PieChartData;

import static android.content.ContentValues.TAG;

public class MainActivity extends AppCompatActivity {



    private FirebaseAuth mAuth;
//    private PieChart pieChart;w

    final Button signUpButton = findViewById(R.id.createUserButton);
    final EditText displayNameEditText =  findViewById(R.id.name_field);
    final EditText usernameEditText = findViewById(R.id.mail_field);
    final EditText passwordEditText = findViewById(R.id.password_field);
    final Button login = findViewById(R.id.login);
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // sets the .xml current view
        setContentView(R.layout.activity_sign_in);
        // pie start
//        pieChart = findViewById(R.id0
//         pie end
//        getEntries();

        // declarations
        mAuth = FirebaseAuth.getInstance();

        signUpButton.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                // calls createAccount
                createAccount(displayNameEditText.getText().toString(), usernameEditText.getText().toString(), passwordEditText.getText().toString());


                // logs in the system that
                Log.v("signUp", "UserSignedUp:"+ usernameEditText.getText().toString() + "password: " + passwordEditText.getText().toString());
                // Logs in the created user
                mAuth.signInWithEmailAndPassword(usernameEditText.getText().toString(),
                        passwordEditText.getText().toString())
                        .addOnCompleteListener(new OnCompleteListener<AuthResult>() {
                            @Override
                            public void onComplete(@NonNull Task<AuthResult> task) {
                                if (task.isSuccessful()) {
//                                    startActivity(new Intent(MainActivity.this, MenuActivity.class));
                                    startActivity(new Intent(MainActivity.this, HomeActivity.class));
                                } else {
                                    Toast.makeText(MainActivity.this, task.getException().getMessage(), Toast.LENGTH_LONG).show();
                                }
                            }
                        });
                // supposed to show a welcome message
//                updateUiWithUser(mAuth.getCurrentUser());
                // shows message to user? maybe?
                Toast.makeText(MainActivity.this, "Register Succeed.",
                        Toast.LENGTH_SHORT).show();
            }
        });

        login.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                // change to Login screen
                startActivity(new Intent(MainActivity.this, LoginActivity.class));
            }
        });
    }



    public void createAccount(final String displayName, String email, String password) {
        mAuth.createUserWithEmailAndPassword(email, password)
                .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
                    @Override
                    public void onComplete(@NonNull Task<AuthResult> task) {

                        if (task.isSuccessful()) {
                            // Sign in success, update UI with the signed-in user's information
                            Log.d(TAG, "createUserWithEmail:success");
                            FirebaseUser user = mAuth.getCurrentUser();
                            // sets the display Name for the user
                            user.updateProfile(new UserProfileChangeRequest.Builder().setDisplayName(displayName).build());
                            startActivity(new Intent(MainActivity.this, LoginActivity.class));
                            updateUiWithUser();
                        } else {
                            // If sign in fails, display a mcessage to the user.
                            Log.w(TAG, "createUserWithEmail:failure", task.getException());
                            Toast.makeText(MainActivity.this, "Authentication failed.",
                                    Toast.LENGTH_SHORT).show();
//                            updateUiWithUser(null);
                        }

                        // TODO discover what to add here
                    }
                });
    }


    private void updateUiWithUser(FirebaseUser model) {
        String welcome = getString(R.string.welcome) + model.getDisplayName();
        // TODO : initiate successful logged in experience
        Toast.makeText(getApplicationContext(), welcome, Toast.LENGTH_LONG).show();
    }
    private void updateUiWithUser() {
        String welcome = getString(R.string.welcome) + mAuth.getCurrentUser().getDisplayName();
        // TODO : initiate successful logged in experience
        Toast.makeText(getApplicationContext(), welcome, Toast.LENGTH_LONG).show();
    }
}

LoginActivity(where the MainActivity goes after registering )

package com.example.appteste.ui.login;

import android.app.Activity;

import androidx.annotation.NonNull;
import androidx.lifecycle.Observer;
import androidx.lifecycle.ViewModelProviders;

import android.content.Intent;
import android.os.Bundle;

import androidx.annotation.Nullable;
import androidx.annotation.StringRes;
import androidx.appcompat.app.AppCompatActivity;

import android.text.Editable;
import android.text.TextWatcher;
import android.util.Log;
import android.view.KeyEvent;
import android.view.View;
import android.view.inputmethod.EditorInfo;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;

import com.example.appteste.HomeActivity;
import com.example.appteste.MenuActivity;
import com.example.appteste.R;
import com.example.appteste.ui.login.LoginViewModel;
import com.example.appteste.ui.login.LoginViewModelFactory;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;

import static android.content.ContentValues.TAG;

public class LoginActivity extends AppCompatActivity {

    private LoginViewModel loginViewModel;
    private FirebaseAuth mAuth;
    private LoginResult login;

    public LoginResult getLogin() {
        return login;
    }

    public void setLogin(LoginResult login) {
        this.login = login;
    }


    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
        loginViewModel = ViewModelProviders.of(this, new LoginViewModelFactory())
                .get(LoginViewModel.class);

        final EditText usernameEditText = findViewById(R.id.username);
        final EditText passwordEditText = findViewById(R.id.password);
        final Button loginButton = findViewById(R.id.login);
        final ProgressBar loadingProgressBar = findViewById(R.id.loading);

        mAuth = FirebaseAuth.getInstance();

        loginViewModel.getLoginFormState().observe(this, new Observer<LoginFormState>() {
            @Override
            public void onChanged(@Nullable LoginFormState loginFormState) {
                if (loginFormState == null) {
                    return;
                }
                loginButton.setEnabled(loginFormState.isDataValid());
                if (loginFormState.getUsernameError() != null) {
                    usernameEditText.setError(getString(loginFormState.getUsernameError()));
                }
                if (loginFormState.getPasswordError() != null) {
                    passwordEditText.setError(getString(loginFormState.getPasswordError()));
                }
            }
        });

        loginViewModel.getLoginResult().observe(this, new Observer<LoginResult>() {
            @Override
            public void onChanged(@Nullable LoginResult loginResult) {
                if (loginResult == null) {
                    return;
                }
                loadingProgressBar.setVisibility(View.GONE);
                if (loginResult.getError() != null) {
                    setLogin(loginResult);
                    showLoginFailed(loginResult.getError());
                }
                if (loginResult.getSuccess() != null) {
//                    updateUiWithUser(loginResult.getSuccess());


                }
                setResult(Activity.RESULT_OK);

                //Complete and destroy login activity once successful
                finish();
            }
        });

        TextWatcher afterTextChangedListener = new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence s, int start, int count, int after) {
                // ignore
            }

            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) {
                // ignore
            }

            @Override
            public void afterTextChanged(Editable s) {
                loginViewModel.loginDataChanged(usernameEditText.getText().toString(),
                        passwordEditText.getText().toString());
            }
        };
        usernameEditText.addTextChangedListener(afterTextChangedListener);
        passwordEditText.addTextChangedListener(afterTextChangedListener);
        passwordEditText.setOnEditorActionListener(new TextView.OnEditorActionListener() {

            @Override
            public boolean onEditorAction(TextView v, int actionId, KeyEvent event) {
                if (actionId == EditorInfo.IME_ACTION_DONE) {
                    loginViewModel.login(usernameEditText.getText().toString(),
                            passwordEditText.getText().toString());
                }
                return false;
            }
        });

        loginButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mAuth.signInWithEmailAndPassword(usernameEditText.getText().toString(),
                        passwordEditText.getText().toString())
                        .addOnCompleteListener(new OnCompleteListener<AuthResult>() {
                    @Override
                    public void onComplete(@NonNull Task<AuthResult> task) {
                        if (task.isSuccessful()) {
                            updateUiWithUser(mAuth.getCurrentUser());
//                            startActivity(new Intent(LoginActivity.this, MenuActivity.class));
                            startActivity(new Intent(LoginActivity.this, HomeActivity.class));
                        } else {
                            Toast.makeText(LoginActivity.this, task.getException().getMessage(), Toast.LENGTH_LONG).show();
                        }
                    }
                });
            }
        });

    }

    // [START on_start_check_user]
    @Override
    public void onStart() {
        super.onStart();
        // Check if user is signed in (non-null) and update UI accordingly.
        FirebaseUser currentUser = mAuth.getCurrentUser();
//        updateUiWithUser(getLogin().getSuccess());
        updateUiWithUser(currentUser);
    }
    // [END on_start_check_user]




    private void updateUiWithUser(FirebaseUser user) {
        String welcome = getString(R.string.welcome) + user.getDisplayName();
        // TODO : initiate successful logged in experience
        Toast.makeText(getApplicationContext(), welcome, Toast.LENGTH_LONG).show();
    }

    private void showLoginFailed(@StringRes Integer errorString) {
        Toast.makeText(getApplicationContext(), errorString, Toast.LENGTH_SHORT).show();
    }


}

my logcat:

2019-10-24 16:39:39.723 711-711/? E/Zygote: isWhitelistProcess - Process is Whitelisted
2019-10-24 16:39:39.723 711-711/? E/Zygote: accessInfo : 1
2019-10-24 16:39:40.209 711-711/com.example.appteste E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.example.appteste, PID: 711
    java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.appteste/com.example.appteste.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.pm.ApplicationInfo android.content.Context.getApplicationInfo()' on a null object reference
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3019)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3256)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1947)
        at android.os.Handler.dispatchMessage(Handler.java:106)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:7037)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:494)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:965)
     Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.content.pm.ApplicationInfo android.content.Context.getApplicationInfo()' on a null object reference
        at android.content.ContextWrapper.getApplicationInfo(ContextWrapper.java:164)
        at android.view.ContextThemeWrapper.getTheme(ContextThemeWrapper.java:157)
        at android.content.Context.obtainStyledAttributes(Context.java:677)
        at androidx.appcompat.app.AppCompatDelegateImpl.createSubDecor(AppCompatDelegateImpl.java:692)
        at androidx.appcompat.app.AppCompatDelegateImpl.ensureSubDecor(AppCompatDelegateImpl.java:659)
        at androidx.appcompat.app.AppCompatDelegateImpl.findViewById(AppCompatDelegateImpl.java:479)
        at androidx.appcompat.app.AppCompatActivity.findViewById(AppCompatActivity.java:214)
        at com.example.appteste.MainActivity.<init>(MainActivity.java:42)
        at java.lang.Class.newInstance(Native Method)
        at android.app.AppComponentFactory.instantiateActivity(AppComponentFactory.java:69)
        at androidx.core.app.CoreComponentFactory.instantiateActivity(CoreComponentFactory.java:41)
        at android.app.Instrumentation.newActivity(Instrumentation.java:1215)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3007)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3256) 
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78) 
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108) 
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1947) 
        at android.os.Handler.dispatchMessage(Handler.java:106) 
        at android.os.Looper.loop(Looper.java:214) 
        at android.app.ActivityThread.main(ActivityThread.java:7037) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:494) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:965)

You're getting an exception. Check the logcat and post the full stacktrace of the exception. — m0skit0, Oct 24 '19 at 18:37
My logcat https://github.com/JesuisOriginal/NoHanggo/blob/master/logcat — DogoLendario Shiba Inu-sama To, Oct 24 '19 at 18:45
in Logcat window choose filter "Show only selected application" in place of "No Filter", and then post Logcat — Rishabh Dhawan, Oct 24 '19 at 18:49
Please *add the Logcat lines related to your app crash here*. Links to other sites may be broken in the future, and so this post would become less helpful for others with a similar problem. — Bö macht Blau, Oct 24 '19 at 18:52
The whole project is open in github for the complete xml and .java files at https://github.com/JesuisOriginal/NoHanggo, still a pretty big logcat even very filtered. — DogoLendario Shiba Inu-sama To, Oct 24 '19 at 19:00
You just need to post the stacktrace of your exception, not the full logcat. Note that I'm not going to clone, compile and install your app just to help you. If you don't want to make an effort for us helping you, then why would I bother? — m0skit0, Oct 24 '19 at 19:00
the logcat was too big for posting, so i put a link to its git rep — DogoLendario Shiba Inu-sama To, Oct 24 '19 at 19:01
The crash log mentions a "SignInActivity" whereas your code snippets don't contain a string "SignInAct". Please post all code necessary to reproduce the problem (aka a [MCVE]) as part of this question — Bö macht Blau, Oct 24 '19 at 19:14
You can't call `findViewById` in the Activity constructor. You need to do it after `setContentView` has been called. — Michael, Oct 24 '19 at 19:17
Possible duplicate of [Unfortunately MyApp has stopped. How can I solve this?](https://stackoverflow.com/questions/23353173/unfortunately-myapp-has-stopped-how-can-i-solve-this) — a_local_nobody, Oct 24 '19 at 19:26

score 0 · Answer 1 · answered Oct 24 '19 at 19:51

 Button signUpButton;
EditText displayNameEditText;
EditText usernameEditText;
EditText passwordEditText;
Button login;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    // sets the .xml current view
    setContentView(R.layout.activity_sign_in);

    signUpButton = findViewById(R.id.createUserButton);
    displayNameEditText =  findViewById(R.id.name_field);
    usernameEditText = findViewById(R.id.mail_field);
    passwordEditText = findViewById(R.id.password_field);
    login = findViewById(R.id.login);

score 0 · Answer 2 · answered Oct 24 '19 at 21:56

You are trying to inflate your views upon class initialization and not in the corresponding life cycle method. As ANDRE OLIVERA suggested, move

final Button signUpButton = findViewById(R.id.createUserButton);
final EditText displayNameEditText =  findViewById(R.id.name_field);
final EditText usernameEditText = findViewById(R.id.mail_field);
final EditText passwordEditText = findViewById(R.id.password_field);
final Button login = findViewById(R.id.login);

Inside onCreate just under setContentView(R.layout.activity_sign_in); which the method that inflates the layout.

Java Android application quickly closes after opening

2 Answers2