Spring 我应该使用Firebase和Mongodb对用户进行身份验证吗？

所以最近我开始写一个android应用程序，我正在使用它 后端是JavaSpring我应该如何实施身份验证？我遵循了谷歌在谷歌的教程签名 用户，然后连接firebase

登录用户

public类MainActivity扩展了AppCompatActivity{
私人签名按钮签名按钮；
私有Google Signinclient mGoodleSignInClient；
私有字符串TAG=“MainActivity”；
私人消防队；
私人按钮btnSignOut；
专用输入RC\u符号IN=1；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.activity_main）；
signInButton=findViewById（R.id.sign_in_按钮）；
mAuth=FirebaseAuth.getInstance（）；
btnSignOut=findviewbyd（R.id.sign\u out\u按钮）；
GoogleSignInOptions gso=新建GoogleSignInOptions.Builder（GoogleSignInOptions.DEFAULT\u SIGN\u IN）.requestIdToken（getString（R.string.DEFAULT\u web\u client\u id））.requestEmail（）.build（）；
mGoodleSignInClient=GoogleSignIn.getClient（this，gso）；
signInButton.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图）{
签名（）；
}
});
btnSignOut.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图v）{
mGoodleSignInClient.signOut（）；
Toast.makeText（MainActivity.this，“您已注销”，Toast.LENGTH_SHORT.show（）；
btnSignOut.setVisibility（View.INVISIBLE）；
}
});
}
私人无效签名（）{
Intent-signinint=mGoodleSignInClient.getsigninint（）；
startActivityForResult（签名、注册）；
}
@凌驾
受保护的void onActivityResult（int-requestCode、int-resultCode、@Nullable-Intent-data）{
super.onActivityResult（请求代码、结果代码、数据）；
if（requestCode==RC\u登录）{
Task Task=GoogleSignIn.GetSignedAccountFromIntent（数据）；
handleSignInResult（任务）；
}
}
私有void handleSignInResult（任务完成任务）{
试一试{
GoogleSignInAccount acc=completedTask.getResult（ApiException.class）；
Toast.makeText（MainActivity.this，“成功登录”，Toast.LENGTH_SHORT.show（）；
字符串idToken=acc.getIdToken（）；
新建CallAPI（idToken）.execute（）；
FirebaseGoogleAuth（acc）；
}
捕获（APIE）{
Toast.makeText（MainActivity.this，“登录失败”，Toast.LENGTH_SHORT.show（）；
FirebaseGoogleAuth（空）；
}
}
私有void FirebaseGoogleAuth（谷歌签名帐户）{
AuthCredential AuthCredential=GoogleAuthProvider.getCredential（acct.getIdToken（），null）；
mAuth.signInWithCredential（authCredential）.addOnCompleteListener（MainActivity.this，新的OnCompleteListener）还是拥有两个数据库毫无意义？
（firebase和mongodb）

    public class MainActivity extends AppCompatActivity {
    private SignInButton signInButton;
    private GoogleSignInClient mGoodleSignInClient;
    private String TAG = "MainActivity";
    private FirebaseAuth mAuth;
    private Button btnSignOut;
    private int RC_SIGN_IN = 1;




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

        signInButton = findViewById(R.id.sign_in_button);
        mAuth = FirebaseAuth.getInstance();
        btnSignOut = findViewById(R.id.sign_out_button);

        GoogleSignInOptions gso = new GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN).requestIdToken(getString(R.string.default_web_client_id)).requestEmail().build();

        mGoodleSignInClient = GoogleSignIn.getClient(this,gso);

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

        btnSignOut.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                mGoodleSignInClient.signOut();
                Toast.makeText(MainActivity.this,"You Are Signed Out", Toast.LENGTH_SHORT).show();
                btnSignOut.setVisibility(View.INVISIBLE);
            }
        });

    }

    private void signIn(){
        Intent signInIntent = mGoodleSignInClient.getSignInIntent();
        startActivityForResult(signInIntent,RC_SIGN_IN);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if(requestCode == RC_SIGN_IN) {
            Task<GoogleSignInAccount> task = GoogleSignIn.getSignedInAccountFromIntent(data);
            handleSignInResult(task);
        }
    }

    private void handleSignInResult(Task<GoogleSignInAccount> completedTask){
        try {

            GoogleSignInAccount acc = completedTask.getResult(ApiException.class);
            Toast.makeText(MainActivity.this,"Signed In Successfully", Toast.LENGTH_SHORT).show();
            String idToken = acc.getIdToken();

            new CallAPI(idToken).execute();
            FirebaseGoogleAuth(acc);
        }
        catch (ApiException e){
            Toast.makeText(MainActivity.this,"Sign In Failed", Toast.LENGTH_SHORT).show();
            FirebaseGoogleAuth(null);

        }

    }

    private void FirebaseGoogleAuth(GoogleSignInAccount acct){
        AuthCredential authCredential = GoogleAuthProvider.getCredential(acct.getIdToken(),null);
        mAuth.signInWithCredential(authCredential).addOnCompleteListener( MainActivity.this,new OnCompleteListener<AuthResult>() {
            @Override
            public void onComplete(@NonNull Task<AuthResult> task){
                if(task.isSuccessful()){
                    Toast.makeText(MainActivity.this,"Successful", Toast.LENGTH_SHORT).show();
                    FirebaseUser user = mAuth.getCurrentUser();
                    try {
                        updateUI(user);
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
                else{
                    Toast.makeText(MainActivity.this,"Failed", Toast.LENGTH_SHORT).show();
                    try {
                        updateUI(null);
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }
        });
    }

    private void updateUI(FirebaseUser fUser) throws IOException {
        btnSignOut.setVisibility(View.VISIBLE);
        GoogleSignInAccount account = GoogleSignIn.getLastSignedInAccount(getApplicationContext());
        if(account != null){

           startActivity(new Intent(MainActivity.this, Profile.class));
            Toast.makeText(MainActivity.this,"Signed in with Google Account" , Toast.LENGTH_SHORT).show();
        }

    }
}

public class CallAPI extends AsyncTask<String,String,String> {

    String idToken;
    public CallAPI(String idToken){
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
    }

    @Override
    protected String doInBackground(String... params) {
        OkHttpClient client = new OkHttpClient();
        FormBody.Builder builder = new FormBody.Builder();
        builder.add("idToken", idToken);
        RequestBody formBody = builder // A sample POST field
                .build();
        Request request = new Request.Builder()
                .url("mybackendurlforacceptingtoken") // The URL to send the data to
                .post(formBody)
                .build();
        return "";
    }

    @Override
    protected void onPostExecute(String s) {
        super.onPostExecute(s);
    }
}