java - 如何在 Firebase 实时数据库中存储用户的提供商帐户？

Question

当我在应用程序中使用Google帐户/facebook帐户登录时，我想将帐户数据记录到firebase实时数据库中，但我无法预期我的目标，因为当我开始登录应用程序和存储处理时，应用程序被强制关闭。

这是我尝试过的代码

LoginActivity.java

package id.co.dolansemarang.loginfirebaseds;

import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.text.TextUtils;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;

import com.facebook.AccessToken;
import com.facebook.CallbackManager;
import com.facebook.FacebookCallback;
import com.facebook.FacebookException;
import com.facebook.login.LoginResult;
import com.facebook.login.widget.LoginButton;
import com.google.android.gms.auth.api.Auth;
import com.google.android.gms.auth.api.signin.GoogleSignIn;
import com.google.android.gms.auth.api.signin.GoogleSignInAccount;
import com.google.android.gms.auth.api.signin.GoogleSignInClient;
import com.google.android.gms.auth.api.signin.GoogleSignInOptions;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.ApiException;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.AuthCredential;
import com.google.firebase.auth.AuthResult;
import com.google.firebase.auth.FacebookAuthProvider;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.auth.GoogleAuthProvider;
import com.google.firebase.database.DatabaseReference;

import id.co.dolansemarang.loginfirebaseds.model.User;
import id.co.dolansemarang.loginfirebaseds.model.UsersProvider;


public class LoginActivity extends BaseActivity implements View.OnClickListener, GoogleApiClient.OnConnectionFailedListener {
    private static final String TAG = "Login User";
    private static final int RC_SIGN_IN = 1234;
    CallbackManager callbackManager;
    GoogleSignInClient googleSignInClient;
    GoogleApiClient mGoogleApiClient;
    LoginButton loginButton;
    Button btnLogin;
    LinearLayout btnGoogleSignIn, btnFacebookSignIn;
    EditText edtEmailLogin, edtPasswordLogin;
    TextView tvResetPass, tvRegisterLink;
    FirebaseAuth firebaseAuthLogin;
    FirebaseAuth.AuthStateListener authStateListener;
    //    DatabaseReference userRefLogin;
    FirebaseUser curUser;
   DatabaseReference providerLoginRef;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
        btnLogin = findViewById(R.id.btn_login);
        edtEmailLogin = findViewById(R.id.edt_email_login);
        edtPasswordLogin = findViewById(R.id.edt_password_login);
        tvResetPass = findViewById(R.id.tv_reset_pass);
        tvRegisterLink = findViewById(R.id.tv_register_link);
        btnGoogleSignIn = findViewById(R.id.btn_sign_in_with_google);
        btnFacebookSignIn = findViewById(R.id.btn_sign_in_with_facebook);
        loginButton = findViewById(R.id.login_button);

        firebaseAuthLogin = FirebaseAuth.getInstance();
//        authStateListener = new FirebaseAuth.AuthStateListener() {
//            @Override
//            public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
//                if (curUser != null) {
//                    Log.d(TAG, "onAuthStateChanged: Sign In");
//                } else {
//                    Log.d(TAG, "onAuthStateChanged:signed_out");
//                }
//            }
//        };
        //Google Sign In
        GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
                .requestIdToken(getString(R.string.default_web_client_id))
                .requestEmail()
                .build();


        mGoogleApiClient = new GoogleApiClient.Builder(LoginActivity.this)
                .enableAutoManage(LoginActivity.this, this)
                .addApi(Auth.GOOGLE_SIGN_IN_API, gso)
                .build();
        googleSignInClient = GoogleSignIn.getClient(this, gso);

        //facebook Sign In
        callbackManager = CallbackManager.Factory.create();

        loginButton.setReadPermissions("email", "public_profile");
        loginButton.registerCallback(callbackManager, new FacebookCallback<LoginResult>() {
            @Override
            public void onSuccess(LoginResult loginResult) {
                Log.d(TAG, "facebook: onSuccess Login" + loginResult);
                handleFacebookAccessToken(loginResult.getAccessToken());

            }

            @Override
            public void onCancel() {
                Log.d(TAG, "facebook: onCancel");

            }

            @Override
            public void onError(FacebookException error) {
                Log.d(TAG, "facebook: onError", error);

            }
        });

        btnFacebookSignIn.setOnClickListener(this);
        btnLogin.setOnClickListener(this);
        tvResetPass.setOnClickListener(this);
        btnGoogleSignIn.setOnClickListener(this);
        tvRegisterLink.setOnClickListener(this);
    }

    private void handleFacebookAccessToken(AccessToken accessToken) {
        Log.d(TAG, "handleFacebookAccessToken : " + accessToken);
        showProgressDialog();
        AuthCredential credential = FacebookAuthProvider.getCredential(accessToken.getToken());
        firebaseAuthLogin.signInWithCredential(credential)
                .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
                    @Override
                    public void onComplete(@NonNull Task<AuthResult> task) {
                        if (task.isSuccessful()) {
                            Log.d(TAG, "your account has been success to register");
                            FirebaseUser user = firebaseAuthLogin.getCurrentUser();
//                            updateUI(user);
                            startActivity(new Intent(getApplicationContext(), MainActivity.class));
                            Toast.makeText(LoginActivity.this, "Welcome " + user.getEmail() + "", Toast.LENGTH_LONG).show();
                            finish();

                        } else {
                            Log.w(TAG, "please, try again", task.getException());
                            Toast.makeText(LoginActivity.this, "Gagal Login, silakan coba lagi", Toast.LENGTH_LONG).show();
//                    updateUI(null);
                        }
                        hideProgressDialog();
                    }
                });
    }

    @Override
    protected void onStart() {
        super.onStart();
        // cek apakah pengguna sudah pernah masuk sehingga ada update UI disini
        if(authStateListener!= null){
            FirebaseUser currentUser = firebaseAuthLogin.getCurrentUser();
            updateUI(currentUser);
            authStateListener.onAuthStateChanged(firebaseAuthLogin);
        }

    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        callbackManager.onActivityResult(requestCode, resultCode, data);
        if (requestCode == RC_SIGN_IN) {
//                GoogleSignInResult result = Auth.GoogleSignInApi.getSignInResultFromIntent(data);
//                handleSignInResult(result);
            Task<GoogleSignInAccount> task = GoogleSignIn.getSignedInAccountFromIntent(data);
            try {
                GoogleSignInAccount account = task.getResult(ApiException.class);
                loginWithGoogle(account);

            } catch (ApiException e) {
                Log.w(TAG, "Google Sign I Failed", e);
                updateUI(curUser);
            }
        }
    }

    private void loginWithGoogle(GoogleSignInAccount account) {
        showProgressDialog();
        AuthCredential credential = GoogleAuthProvider.getCredential(account.getIdToken(), null);
        firebaseAuthLogin.signInWithCredential(credential)
                .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
                    @Override
                    public void onComplete(@NonNull Task<AuthResult> task) {
                        if (task.isSuccessful()) {

                            String uid = FirebaseAuth.getInstance().getCurrentUser().getUid();
                            String nama =FirebaseAuth.getInstance().getCurrentUser().getDisplayName();
                            String email = FirebaseAuth.getInstance().getCurrentUser().getEmail();
                            String providerID =FirebaseAuth.getInstance().getCurrentUser().getProviderId();
                            UsersProvider users = new UsersProvider (uid,nama,email,providerID);

                            providerLoginRef.child("UsersProviders").child(uid).setValue(users).addOnCompleteListener(LoginActivity.this, new OnCompleteListener<Void>() {
                                @Override
                                public void onComplete(@NonNull Task<Void> task) {
                                    updateUI(curUser);
                                }
                            });

                        } else {
                            Log.w(TAG, "please, try again", task.getException());
                            Toast.makeText(LoginActivity.this, "Gagal Login, silakan coba lagi", Toast.LENGTH_LONG).show();
                        }
                        hideProgressDialog();
                    }
                });
    }

    private void loginUserWithEmail(String email, String password) {
        Log.d(TAG, "signIn:" + email);
        if (!validateForm()) {
            return;
        }
        showProgressDialog();
        firebaseAuthLogin.signInWithEmailAndPassword(email, password).addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
            @Override
            public void onComplete(@NonNull Task<AuthResult> task) {
                if (task.isSuccessful()) {
                    Log.d(TAG, "your account has been success to register");
                    FirebaseUser user = firebaseAuthLogin.getCurrentUser();
                    if (user.isEmailVerified()) {
                        updateUI(user);
                    } else {
                        Toast.makeText(LoginActivity.this, "Silakan cek inbox untuk verifikasi", Toast.LENGTH_LONG).show();
                    }
                } else {
                    Log.w(TAG, "please, try again", task.getException());
                    Toast.makeText(LoginActivity.this, "Gagal Login, silakan coba lagi", Toast.LENGTH_LONG).show();
//                    updateUI(null);
                }
                hideProgressDialog();
            }
        });
    }

    private void updateUI(FirebaseUser user) {
        hideProgressDialog();
        if (user != null) {
            user.getDisplayName();
            startActivity(new Intent(LoginActivity.this, MainActivity.class));
            Toast.makeText(this, "Welcome " + user.getEmail() + "", Toast.LENGTH_LONG).show();
            finish();
        }
    }

    private boolean validateForm() {
        boolean valid = true;
        String email = edtEmailLogin.getText().toString();
        String password = edtPasswordLogin.getText().toString();

        if (TextUtils.isEmpty(email)) {
            Toast.makeText(getApplicationContext(), "Harap isi email kembali", Toast.LENGTH_LONG).show();
            valid = false;
        } else {
            if (TextUtils.isEmpty(password)) {
                Toast.makeText(getApplicationContext(), "Harap isi password kembali", Toast.LENGTH_LONG).show();
                valid = false;
            } else {
                if (password.length() <= 6) {
                    Toast.makeText(getApplicationContext(), "password contained minimum 6 character", Toast.LENGTH_LONG).show();
                    valid = false;
                }
            }
        }
        return valid;
    }

    @Override
    public void onClick(View v) {
        int i = v.getId();
        if (i == R.id.btn_login) {
            loginUserWithEmail(edtEmailLogin.getText().toString(), edtPasswordLogin.getText().toString());
        } else if (i == R.id.tv_reset_pass) {
            startActivity(new Intent(LoginActivity.this, ResetPasswordActivity.class));
            finish();
        } else if (i == R.id.btn_sign_in_with_google) {
            signInGoogle();
        } else if (i == R.id.tv_register_link) {
            gotoRegister();
        } else if (i == R.id.btn_sign_in_with_facebook) {
            loginButton.performClick();
        }

    }

    private void gotoRegister() {
        startActivity(new Intent(this, RegisterActivity.class));
        finish();
    }

    private void signInGoogle() {
        Intent signIntent = googleSignInClient.getSignInIntent();
        startActivityForResult(signIntent, RC_SIGN_IN);
    }

    @Override
    protected void onStop() {
        super.onStop();
        if (authStateListener != null) {
            firebaseAuthLogin.removeAuthStateListener(authStateListener);
        }
    }

    @Override
    public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {

    }
}

我希望我可以存储，但情况相反，因为 logcat 显示这样的错误

2019-05-04 20:55:13.471 16495-16495/id.co.dolansemarang.loginfirebaseds E/AndroidRuntime: FATAL EXCEPTION: main
    Process: id.co.dolansemarang.loginfirebaseds, PID: 16495
    java.lang.NullPointerException: Attempt to invoke virtual method 'com.google.firebase.database.DatabaseReference com.google.firebase.database.DatabaseReference.child(java.lang.String)' on a null object reference
        at id.co.dolansemarang.loginfirebaseds.LoginActivity$3.onComplete(LoginActivity.java:203)
        at com.google.android.gms.tasks.zzj.run(Unknown Source)
        at android.os.Handler.handleCallback(Handler.java:751)
        at android.os.Handler.dispatchMessage(Handler.java:95)
        at android.os.Looper.loop(Looper.java:154)
        at android.app.ActivityThread.main(ActivityThread.java:6776)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1518)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1408)

我希望你能帮助我。先谢谢了

Answer 1

要解决此问题，请更改以下代码行:

DatabaseReference providerLoginRef;

至

DatabaseReference providerLoginRef = FirebaseDatabase.getInstance().getReference();

所以您收到该错误是因为您的 providerLoginRef 对象从未初始化。