如何获取当前用户的Firebase令牌

Question

我正在构建一个应用程序，登录用户可以通过按按钮邀请另一个用户，这样被邀请的用户就会收到推送通知。我的想法是，如果我可以在数据库中保存每个用户的令牌，那么当用户按下“邀请按钮”时，它会在数据库中找到该用户令牌，之后我将以某种方式使用它向该用户发送通知用户。我不知道是否有更好的方法，但我没有找到其他任何东西，所以这就是我目前的计划。

\n

现在我遇到了一些有关如何将令牌保存到数据库的问题。每当用户创建帐户或令牌更改时，我想将其保存到数据库中。

\n

public class RegisterActivity extends AppCompatActivity {\n\n    private FirebaseAuth mAuth;\n\n    String username;\n    String password;\n    String age;\n    String email;\n    \n    DatabaseReference mRootRef = FirebaseDatabase.getInstance().getReference();\n    DatabaseReference mRootPlayerBaseRef = mRootRef.child("Players");\n\n    private static final String TAG = "EmailPassword";\n\n    @Override\n    protected void onCreate(Bundle savedInstanceState) {\n        super.onCreate(savedInstanceState);\n        setContentView(R.layout.activity_register);\n\n        // [START initialize_auth]\n        // Initialize Firebase Authentication\n        mAuth = FirebaseAuth.getInstance();\n        // [END initialize_auth]\n    }\n\n\n    private void updateUI() {\n        Intent mainIntent = new Intent(RegisterActivity.this, LoginActivity.class);\n        mainIntent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TASK);\n        mainIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);\n        startActivity(mainIntent);\n        overridePendingTransition(android.R.anim.fade_in, android.R.anim.fade_out);\n    }\n\n    public void checkValues(View view) {\n        final EditText userEdit = (EditText) findViewById(R.id.username_field);\n        username = userEdit.getText().toString();\n        final EditText emailEdit = (EditText) findViewById(R.id.email_field);\n        email = emailEdit.getText().toString();\n        final EditText passwordEdit = (EditText) findViewById(R.id.password_field);\n        password = passwordEdit.getText().toString();\n        final EditText ageEdit = (EditText) findViewById(R.id.age_field);\n        age = ageEdit.getText().toString();\n\n\n        if (username.equals("") || email.equals("") || password.equals("") || age.equals("")){\n            Toast.makeText(RegisterActivity.this, "Please fill in all information", Toast.LENGTH_LONG).show();\n            return;}\n\n        if (username.length() < 4){\n            Toast.makeText(RegisterActivity.this, "Username has to be at least 4 characters", Toast.LENGTH_LONG).show();\n            return;\n        }\n\n        if (Integer.parseInt(age) < 5 || Integer.parseInt(age) > 120){\n            Toast.makeText(RegisterActivity.this, "Enter a valid age", Toast.LENGTH_LONG).show();\n            return;\n        }\n\n        //last thing to check is if username already exists\n        checkUsedUsername(username);\n\n    }\n\n    public void login(View view) {\n        Intent mainIntent = new Intent(RegisterActivity.this, LoginActivity.class);\n        startActivity(mainIntent);\n        overridePendingTransition(android.R.anim.fade_in, android.R.anim.fade_out);\n    }\n\n    public void checkUsedUsername(final String username){\n        mRootPlayerBaseRef.addListenerForSingleValueEvent(new ValueEventListener() {\n            @Override\n            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {\n                //check if username exist otherwise create account\n                for (DataSnapshot data: dataSnapshot.getChildren()) {\n                    if (username.equals(data.child("username").getValue())){\n                        Toast.makeText(RegisterActivity.this, "Username already taken", Toast.LENGTH_LONG).show();\n                        return;}\n                }\n                createAccount();\n            }\n\n            @Override\n            public void onCancelled(@NonNull DatabaseError databaseError) {\n                Toast.makeText(RegisterActivity.this, "Error", Toast.LENGTH_SHORT).show();\n                Toast.makeText(RegisterActivity.this, databaseError.getMessage(), Toast.LENGTH_SHORT).show();\n            }\n        });\n    }\n\n    private void createAccount(){\n        // [START create_user_with_email], built in function which checks if user can be created and insert it into auth database\n        mAuth.createUserWithEmailAndPassword(email, password)\n                .addOnCompleteListener(this, new OnCompleteListener<AuthResult>() {\n                    @Override\n                    public void onComplete(@NonNull Task<AuthResult> task) {\n                        //if this was successful the user will now be in the database\n                        if (task.isSuccessful()) {\n                            //fetch the user\n                            FirebaseUser user = mAuth.getCurrentUser();\n\n                            //this set the created users getDisplayName() = username\n                            UserProfileChangeRequest profileUpdates = new UserProfileChangeRequest.Builder()\n                                    .setDisplayName(username).build();\n                            assert user != null;\n                            user.updateProfile(profileUpdates);\n\n                            //Here I would like to get the token so I can save it when a user is created\n\n                            //get unique user id\n                            String userID = user.getUid();\n                            //create the user that will be inserted into the database\n                            Player newPlayer = new Player(username, age, email);\n                            //adding child(userID) will make we don\xc2\xb4t replace previous user and actually insert new user, it becomes the key\n                            mRootPlayerBaseRef.child(userID).setValue(newPlayer);\n\n                            Toast.makeText(RegisterActivity.this, "Account was created successfully", Toast.LENGTH_LONG).show();\n                            updateUI();\n                        } else {\n                            try\n                            {\n                                throw Objects.requireNonNull(task.getException());\n                            }\n                            // if user enters wrong email.\n                            catch (FirebaseAuthWeakPasswordException weakPassword)\n                            {\n                                Log.d(TAG, "onComplete: weak_password");\n                                Toast.makeText(RegisterActivity.this, "Password to weak", Toast.LENGTH_LONG).show();\n                            }\n                            // if user enters wrong password.\n                            catch (FirebaseAuthInvalidCredentialsException malformedEmail)\n                            {\n                                Log.d(TAG, "onComplete: malformed_email");\n                                Toast.makeText(RegisterActivity.this, "Wrong email", Toast.LENGTH_LONG).show();\n                            }\n                            catch (FirebaseAuthUserCollisionException existEmail)\n                            {\n                                Log.d(TAG, "onComplete: exist_email");\n                                Toast.makeText(RegisterActivity.this, "Email already exists", Toast.LENGTH_LONG).show();\n                            }\n                            catch (Exception e)\n                            {\n                                Toast.makeText(RegisterActivity.this, "Error", Toast.LENGTH_SHORT).show();\n                                Toast.makeText(RegisterActivity.this, "Please try again", Toast.LENGTH_SHORT).show();\n                            }\n                        }\n\n                    }\n                });\n        // [END create_user_with_email]\n    }\n}\n

\n

public class MessagingService extends FirebaseMessagingService {\n\n    @Override\n    public void onNewToken(String s) {\n        super.onNewToken(s);\n        Log.d("NEW_TOKEN",s); //here we get the token so we can communicate with the database\n    }\n\n    //does not work as "Method does not override method from its superclass"\n    @Override\n    public void onTokenRefresh() {\n        super.onTokenRefresh();\n\n    }\n}\n

\n

我想要做的是将用户中的令牌与其他变量（例如用户名、年龄等）一起保存在数据库中。

\n

我希望能有这样的东西来获取令牌，但似乎并非如此：

\n

FirebaseAuth.getInstance().getCurrentUser().getIdToken(true) //this does not work\n

\n

所以我真正要问的是如何获取用户的当前令牌？

\n

Answer 1

Firebase Cloud Messaging 令牌对于设备而言是唯一的，而不是对于用户而言。它不了解有关 Firebase Auth 用户的任何信息，并且 Firebase Auth 不了解有关 FCM 设备令牌的任何信息。

您将需要存储用户与其设备令牌的映射。由于用户可能使用多个设备，因此您的数据结构应允许每个用户使用多个令牌。然后，您的后端代码应该查询这些令牌并将消息发送给每个令牌（如果这是您的用户想要的）。