android - 从 firebase 实时数据库获取用户数据返回 null

Question

我需要帮助。当我注册用户时，用户数据会上传到“用户”表。在主要活动中，我试图获取该数据，但出现错误

这是主要活动

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        phone = findViewById(R.id.profilePhone);
        fullName = findViewById(R.id.profileName);
        email    = findViewById(R.id.profileEmail);
        resetPassLocal = findViewById(R.id.resetPasswordLocal);

        profileImage = findViewById(R.id.profileImage);
        changeProfileImage = findViewById(R.id.changeProfile);


        fAuth = FirebaseAuth.getInstance();
        fStore = FirebaseFirestore.getInstance();
        storageReference = FirebaseStorage.getInstance().getReference();
        firebaseDatabase = FirebaseDatabase.getInstance();
        reference = FirebaseDatabase.getInstance().getReference("user");


        StorageReference profileRef = storageReference.child("users/"+fAuth.getCurrentUser().getUid()+"/profile.jpg");
        profileRef.getDownloadUrl().addOnSuccessListener(new OnSuccessListener<Uri>() {
            @Override
            public void onSuccess(Uri uri) {
                Picasso.get().load(uri).into(profileImage);
            }
        });

        resendCode = findViewById(R.id.resendCode);
        verifyMsg = findViewById(R.id.verifyMsg);


        userId = fAuth.getCurrentUser().getUid();
        user = fAuth.getCurrentUser();

        if(!user.isEmailVerified()){
           
        reference.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot snapshot) {


                    users_model user = snapshot.getValue(users_model.class);
                    String userName = user.getName();
                    String userPhone = user.getPhone();
                    String useremail = user.getEmail();

                    fullName.setText(userName);
                    phone.setText(userPhone);
                    email.setText(useremail);


            }

            @Override
            public void onCancelled(@NonNull DatabaseError error) {
                Toast.makeText(getApplicationContext(), "Something went wrong", Toast.LENGTH_LONG).show();
            }
      

        changeProfileImage.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                // open gallery
                Intent i = new Intent(v.getContext(),EditProfile.class);
                i.putExtra("fullName",fullName.getText().toString());
                i.putExtra("email",email.getText().toString());
                i.putExtra("phone",phone.getText().toString());
                startActivity(i);


            }
        });


    }

这是模型类

public class users_model {

    private String name;
    private String email;
    private String phone;
    private String type;

    public users_model() {
    }

    public users_model(String name, String email, String phone, String type) {
        this.name = name;
        this.email = email;
        this.phone = phone;
        this.type = type;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }

    public String getType() {
        return type;
    }

    public void setType(String type) {
        this.type = type;
    }
}

这是错误

E/AndroidRuntime：致命异常：主进程：com.example.firebase_auth，PID：27880 java.lang.NullPointerException：尝试调用虚拟方法'java.lang.String com.example.firebase_auth.users_model.getName（）'在 com.google.firebase.database.core.ValueEventRegistration.fireEvent(ValueEventRegistration.java:75) 在 com.google.firebase.database 的 com.example.firebase_auth.MainActivity$3.onDataChange(MainActivity.java:126) 的空对象引用.core.view.DataEvent.fire(DataEvent.java:63) 在 com.google.firebase.database.core.view.EventRaiser$1.run(EventRaiser.java:55) 在 android.os.Handler.handleCallback(Handler. java:873) 在 android.os.Handler.dispatchMessage(Handler.java:99) 在 android.os.Looper.loop(Looper.java:193) 在 android.app.ActivityThread.main(ActivityThread.java:6669) 在java.lang.reflect.方法。在 com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858) 的 com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493) 调用（本机方法）

Firebase 数据库结构

标签： androidfirebase-realtime-databasefirebase-authentication