Question

我有一个Android应用，目前有约2k活跃用户。它使用Firebase Firestore数据库保存用户数据和其他内容。但是最近我从readUserDataFromDatabase函数中收到了此错误并崩溃报告：

    private void readUserDataFromDatabase(String uid) {
    db.collection(Constants.PARAM_USERS)
            .document(uid) // (MainActivity.java:215)This is where the crash happens 
            .get()
            .addOnSuccessListener(new OnSuccessListener<DocumentSnapshot>() {
                @Override
                public void onSuccess(DocumentSnapshot documentSnapshot) {
                    UserData userData = documentSnapshot.toObject(UserData.class);
                    if (userData == null) 
                        return;

                    tvName.setText(getString(R.string.welcome, userData.getName()));

                    Picasso
                            .get()
                            .load(userData.getPhotoUrl())
                            .placeholder(getResources().getDrawable(R.drawable.place_holder))
                            .transform(new RoundedCornersTransform())
                            .into(ivPhoto);

                    UserData.getInstance().setCredit(userData.getCredit());
                    UserData.getInstance().setPhotoUrl(userData.getPhotoUrl());
                    UserData.getInstance().setName(userData.getName());

                    if (userData.getInstanceId() != null) {
                        UserData.getInstance().setInstanceId(userData.getInstanceId());
                    }
                }
            });

}

此功能在成功完成登录过程后从登录活动重定向后运行：

private void setUser(final FirebaseUser user) {
    if (user == null)
        return;

    UserData.getInstance().setUserId(user.getUid());// I'm using this Uid for create node for user.
    DocumentReference docRef = db.collection(Constants.PARAM_USERS).document(user.getUid());

    docRef
            .get()
            .addOnSuccessListener(new OnSuccessListener<DocumentSnapshot>() {
                @Override
                public void onSuccess(DocumentSnapshot documentSnapshot) {
                    UserData userData = documentSnapshot.toObject(UserData.class);
                    if (userData == null) {
                        createUser(user);
                    } else {
                        redirectToHome(); //login succeed
                    }
                }
            }).addOnFailureListener(new OnFailureListener() {
        @Override
        public void onFailure(@NonNull Exception e) {

        }
    });
}

并从重定向的活动中调用readUserDataFromDatabase函数，如下所示：

 readUserDataFromDatabase(UserData.getInstance().getUserId());

崩溃率大约为％1，但仍然看不到这里缺少的内容。 firebase用户ID是否有可能返回null或登录成功后，readUserDataFromDatabase在

之前运行

UserData.getInstance().setUserId(user.getUid());

功能？我不知道。谢谢。

编辑1：添加了堆栈跟踪。

致命异常：java.lang.RuntimeException：无法启动活动 ComponentInfo {com.alialacan.kpss / com.alialacan.kpss.MainActivity}： java.lang.NullPointerException：提供的文档路径不得为空值。在android.app.ActivityThread.performLaunchActivity（ActivityThread.java:2781）在android.app.ActivityThread.handleLaunchActivity（ActivityThread.java:2859）在android.app.ActivityThread.-wrap11（未知来源）在android.app.ActivityThread $ H.handleMessage（ActivityThread.java:1592）在android.os.Handler.dispatchMessage（Handler.java:106）在android.os.Looper.loop（Looper.java:164）在android.app.ActivityThread.main（ActivityThread.java:6518）在java.lang.reflect.Method.invoke（Method.java）在com.android.internal.os.RuntimeInit $ MethodAndArgsCaller.run（RuntimeInit.java:438）在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:807）
Caused by java.lang.NullPointerException: Provided document path must not be null.
       at com.google.common.base.Preconditions.checkNotNull(Preconditions.java:228)
       at com.google.firebase.firestore.CollectionReference.document(SourceFile:90)
       at com.alialacan.kpss.MainActivity.readUserDataFromDatabase(MainActivity.java:215)
       at com.alialacan.kpss.MainActivity.onCreate(MainActivity.java:114)
       at android.app.Activity.performCreate(Activity.java:7013)
       at android.app.Activity.performCreate(Activity.java:7004)
       at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1215)
       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2734)
       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2859)
       at android.app.ActivityThread.-wrap11(Unknown Source)
       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1592)
       at android.os.Handler.dispatchMessage(Handler.java:106)
       at android.os.Looper.loop(Looper.java:164)
       at android.app.ActivityThread.main(ActivityThread.java:6518)
       at java.lang.reflect.Method.invoke(Method.java)
       at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)

编辑2：这里是 setUser 函数的调用位置：

    @Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    callbackManager.onActivityResult(requestCode, resultCode, data);

    if (requestCode == Constants.RC_SIGN_IN) {
        GoogleSignInResult result = Auth.GoogleSignInApi.getSignInResultFromIntent(data);
        if (result.isSuccess()) {
            GoogleSignInAccount account = result.getSignInAccount();
            firebaseAuthWithGoogle(account);
        } else {
            Toast.makeText(LoginActivity.this, R.string.error_google_login,
                    Toast.LENGTH_SHORT).show();
            hideProgress();
        }
    }
}

 private void handleFacebookAccessToken(AccessToken token) {
    Log.d("", "handleFacebookAccessToken:" + token);

    AuthCredential credential = FacebookAuthProvider.getCredential(token.getToken());
    auth.signInWithCredential(credential)
            .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
                @Override
                public void onComplete(@NonNull Task<AuthResult> task) {
                    if (task.isSuccessful()) {                          
                        Log.d("", "signInWithCredential:success");
                        user = auth.getCurrentUser();
                        setUser(user);
                    } else {
                        setUser(null);
                        Log.w("", "signInWithCredential:failure", task.getException());
                        Toast.makeText(LoginActivity.this, R.string.error_email_already_exist,
                                Toast.LENGTH_SHORT).show();
                        hideProgress();
                    }
                }
            });
}

 private void firebaseAuthWithGoogle(GoogleSignInAccount acct) {
    AuthCredential credential = GoogleAuthProvider.getCredential(acct.getIdToken(), null);
    auth.signInWithCredential(credential)
            .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {
                @Override
                public void onComplete(@NonNull Task<AuthResult> task) {
                    if (task.isSuccessful()) {
                        FirebaseUser user = auth.getCurrentUser();
                        setUser(user);
                    } else {
                        Toast.makeText(LoginActivity.this, R.string.error_google_login,
                Toast.LENGTH_SHORT).show();
                        setUser(null);
                        hideProgress();
                    }
                }
            });
}

Answer 1

错误消息说此代码正在将null值传递给readUserDataFromDatabase

readUserDataFromDatabase(UserData.getInstance().getUserId());

这意味着UserData.getInstance().getUserId()返回null。

这里实际上没有足够的代码来完全诊断问题，因为您也没有显示调用setUser的内容，但是您需要将此代码追溯到源代码。

Answer 2

对我来说，清除缓存对我有所帮助

collection("Posts").orderBy("timestamp",Query.Direction.DESCENDING)至collection("Posts").orderBy("like_count",Query.Direction.DESCENDING)

如何防止“ Firestore，提供的文档路径不能为空”错误？

2 个答案: