java - 没有什么可以保存到 Firebase

Question

我对使用 android studio 制作应用程序还很陌生，有人建议我遵循我所做的教程。在我运行该程序之前一切都很好，并且由于某种原因没有什么可以保存到 firebase。如果这是一个简单的问题，我很抱歉，但正如我所说，我对 Java 和应用程序编程都是全新的。

我试着逐行查看代码并将其与教程制作者的代码进行比较。

    package com.hossain.mylearningproject;

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

    import android.app.ProgressDialog;
    import android.content.Intent;
    import android.os.Bundle;
    import android.text.TextUtils;
    import android.view.View;
    import android.widget.Button;
    import android.widget.EditText;
    import android.widget.Toast;

    import com.google.android.gms.tasks.OnCompleteListener;
    import com.google.android.gms.tasks.Task;
    import com.google.firebase.database.DataSnapshot;
    import com.google.firebase.database.DatabaseError;
    import com.google.firebase.database.DatabaseReference;
    import com.google.firebase.database.FirebaseDatabase;
    import com.google.firebase.database.ValueEventListener;

    import java.util.HashMap;

    public class RegisterActivity extends AppCompatActivity {

    private Button CreateAccountBtn;
    private EditText Inputname, InputPhoneNumber, InputPassword;
    private ProgressDialog LoadingBar;


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

        CreateAccountBtn = (Button) findViewById(R. id. register_btn);
        Inputname = (EditText) findViewById(R. id. register_username_input);
        InputPhoneNumber = (EditText) findViewById(R. id. register_phone_number_input);
        InputPassword = (EditText) findViewById(R. id. register_password_input);
        LoadingBar = (ProgressDialog) new ProgressDialog(this);

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


    private void CreateAccount(){
        String name = Inputname.getText().toString();
        String phonenumber = InputPhoneNumber.getText().toString();
        String password = InputPassword.getText().toString();

        if (TextUtils.isEmpty(name)){
            Toast.makeText(this, "Please Write you're name...", Toast.LENGTH_SHORT).show();
        }
        else if (TextUtils.isEmpty(phonenumber)){
            Toast.makeText(this, "Please Write you're phone number...", Toast.LENGTH_SHORT).show();
        }
        else if (TextUtils.isEmpty(password)){
            Toast.makeText(this, "Please Write you're Password...", Toast.LENGTH_SHORT).show();
        }
        else{
            LoadingBar.setTitle("Create account");
            LoadingBar.setMessage("Please wait while we check the credentialls.");
            LoadingBar.setCanceledOnTouchOutside(false);
            LoadingBar.show();

            ValidateCredentialls(name, phonenumber);
        }
    }

    private void ValidateCredentialls(final String name, final String phonenumber){
        final DatabaseReference Rootref;
        Rootref = FirebaseDatabase.getInstance().getReference();
        Rootref.addListenerForSingleValueEvent(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                if (!(dataSnapshot.child("Users").child(phonenumber).exists())){
                    HashMap<String, Object> Userdatamap = new HashMap<>();
                            Userdatamap.put("phone number", phonenumber);
                            Userdatamap.put("Username", name);
                            Userdatamap.put("password", InputPassword);

                            Rootref.child("Users").child(phonenumber).updateChildren(Userdatamap)
                                    .addOnCompleteListener(new OnCompleteListener<Void>()
                                    {
                                        @Override
                                        public void onComplete(@NonNull Task<Void> task)
                                        {
                                            if(task.isSuccessful())
                                            {
                                                Toast.makeText(RegisterActivity.this, "Congratulations, you're account has now been created", Toast.LENGTH_SHORT).show();
                                                LoadingBar.dismiss();

                                                Intent intent = new Intent(RegisterActivity.this, LoginActivity.class);
                                                startActivity(intent);

                                            }
                                            else
                                                {
                                                LoadingBar.dismiss();
                                                Toast.makeText(RegisterActivity.this, "Connection problem, Please check you're internet connection.", Toast.LENGTH_SHORT).show();
                                            }
                                        }
                                    });
                }
                else
                    {
                    Toast.makeText(RegisterActivity.this, "An account with " + phonenumber + " already exists", Toast.LENGTH_SHORT).show();
                    LoadingBar.dismiss();
                    Toast.makeText(RegisterActivity.this, "Please try again using a diffrent phone number", Toast.LENGTH_SHORT).show();

                    Intent intent = new Intent(RegisterActivity.this, MainActivity.class);
                    startActivity(intent);
                }
            }

            @Override
            public void onCancelled(@NonNull DatabaseError databaseError) {

            }
        });
    }
}

我希望它能使用不同的“ child ”保存到 firebase，但没有保存任何内容

我已将此发布到 SuperUser，但在查看其他问题时我意识到有人实际回复的几率非常低:/，我也有一些很棒的经验可以在这里快速轻松地获得答案。

Answer 1

我遇到过同样的问题，然后我才知道它只是因为这条规则我无法在我的数据库中写入任何内容。 创建一个数据模型，比如

data class User(
var email: String? = "",
var name: String? = "",
var phoneNumber:String? =""
)

现在为了写入 firebase 数据库，您需要做的就是创建一个 firebase 数据库实例

 database = FirebaseDatabase.getInstance().getReference("users")

然后将值添加到您的模型并将其传递到数据库

 val user = User("abc.gmail.com, "abc",
        "858689849")
    database.child(userId).setValue(user)

在你的情况下。

  private void ValidateCredentialls(final String name, final String phonenumber){
    final DatabaseReference Rootref;
    Rootref = FirebaseDatabase.getInstance().getReference("users")
   ;
    User user =new  User("abc.gmail.com, "abc",
    "858689849");
database.child(userId).setValue(user)
}