Question

我试图在我的数据库中保存用户的数据，但我有时会从以下位置获得空值：

currentUser = dataSnapshot.getValue(User.class);

密钥正确指向用户ID，但值为null

这是我的代码：

package com.example.eltobgy.yala;

import android.app.ProgressDialog;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.v7.app.AppCompatActivity;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.widget.Toast;

import com.firebase.ui.auth.AuthUI;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.auth.FirebaseUser;
import com.google.firebase.database.ChildEventListener;
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.Arrays;
import java.util.List;

public class MainActivity extends AppCompatActivity {

    private static final String ANONYMOUS = "Anonymous";
    // Choose an arbitrary request code value
    private static final int RC_SIGN_IN = 1;
    public static DatabaseReference mDatabaseReference;
    public static FirebaseDatabase mDatabase;
    public static User currentUser;
    // Firebase
    private FirebaseAuth mFirebaseAuth;
    private FirebaseAuth.AuthStateListener mAuthStateListener;
    private ChildEventListener mChildEventListener;
    private String mUsername;
    private ProgressDialog progressDialog;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        progressDialog = new ProgressDialog(this);
        progressDialog.setMessage("Signing you in ...");
        progressDialog.show();

        mUsername = ANONYMOUS;
        mFirebaseAuth = FirebaseAuth.getInstance();
        mDatabase = FirebaseDatabase.getInstance();
        currentUser = null;
        mDatabaseReference = mDatabase.getReference().child("users");

        mAuthStateListener = new FirebaseAuth.AuthStateListener() {
            @Override
            public void onAuthStateChanged(@NonNull FirebaseAuth firebaseAuth) {
                FirebaseUser firebaseUser = firebaseAuth.getCurrentUser();
                if (firebaseUser != null) {
                    // User is signed in
                    onSignedInInitialize(firebaseUser.getDisplayName());
                    DatabaseReference userDatabaseRefrence = mDatabaseReference.child(firebaseUser.getUid());

                    ValueEventListener valueEventListener = new ValueEventListener() {
                        @Override
                        public void onDataChange(DataSnapshot dataSnapshot) {
                            currentUser = dataSnapshot.getValue(User.class);
                            progressDialog.dismiss();
                            if (currentUser.isBasicInfo()) {
                                if (currentUser.getCurrentType().equals("")) {

                                    Intent intent = new Intent(MainActivity.this, UserTypeActivity.class);
                                    startActivity(intent);
                                } else if (currentUser.getCurrentType().equals("t")) {
                                    if (!currentUser.isDeliveryModeActivation()) {
                                        Intent intent = new Intent(MainActivity.this, DeliveryManExtraInfoActivity.class);
                                        startActivity(intent);
                                    } else {
                                        Intent intent = new Intent(MainActivity.this, HomeActivity.class);
                                        startActivity(intent);
                                    }
                                } else {
                                    Intent intent = new Intent(MainActivity.this, HomeActivity.class);
                                    startActivity(intent);
                                }
                            } else {
                                Intent intent = new Intent(MainActivity.this, BasicInfoActivity.class);
                                startActivity(intent);
                            }
                        }

                        @Override
                        public void onCancelled(DatabaseError databaseError) {
                            Toast.makeText(MainActivity.this, "cancelled", Toast.LENGTH_SHORT).show();
                        }
                    };
                    userDatabaseRefrence.addValueEventListener(valueEventListener);
                } else {
                    // User is signed out
                    onSignedOutCleanup();

                    List<AuthUI.IdpConfig> providers = Arrays.asList(
                            new AuthUI.IdpConfig.Builder(AuthUI.EMAIL_PROVIDER).build(),
                            new AuthUI.IdpConfig.Builder(AuthUI.GOOGLE_PROVIDER).build());

                    startActivityForResult(
                            AuthUI.getInstance()
                                    .createSignInIntentBuilder()
                                    .setIsSmartLockEnabled(false)
                                    .setAvailableProviders(providers)
                                    .setTheme(R.style.LoginTheme)
                                    .build(),
                            RC_SIGN_IN);
                }
            }
        };
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == RC_SIGN_IN) {
            if (resultCode == RESULT_OK) {
                // Sign-in succeeded, set up the UI
                mDatabaseReference.addListenerForSingleValueEvent(new ValueEventListener() {
                    @Override
                    public void onDataChange(DataSnapshot dataSnapshot) {
                        if (!dataSnapshot.exists()) {
                            FirebaseUser firebaseUser = FirebaseAuth.getInstance().getCurrentUser();
                            User user = new User(firebaseUser.getUid(), firebaseUser.getDisplayName(), firebaseUser.getEmail());
                            mDatabaseReference.child(user.getId()).setValue(user);
                        }
                    }

                    @Override
                    public void onCancelled(DatabaseError databaseError) {

                    }
                });
            } else if (resultCode == RESULT_CANCELED) {
                // Sign in was canceled by the user, finish the activity
                Toast.makeText(this, "Sign in canceled", Toast.LENGTH_SHORT).show();
                finish();
            }
        }
    }


    private void onSignedInInitialize(String username) {
        mUsername = username;

    }

    private void onSignedOutCleanup() {
        mUsername = ANONYMOUS;
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.options_menu, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.sign_out_menu:
                AuthUI.getInstance().signOut(this).addOnCompleteListener(new OnCompleteListener<Void>() {
                    public void onComplete(@NonNull Task<Void> task) {
                        // user is now signed out
                        startActivity(new Intent(MainActivity.this, MainActivity.class));
                        finish();
                    }
                });
                return true;
            default:
                return super.onOptionsItemSelected(item);
        }
    }

    @Override
    protected void onPause() {
        super.onPause();
        if (mAuthStateListener != null) {
            mFirebaseAuth.removeAuthStateListener(mAuthStateListener);
        }
        //mMessageAdapter.clear();
        //detachDatabaseReadListener();
    }

    @Override
    protected void onResume() {
        super.onResume();
        mFirebaseAuth.addAuthStateListener(mAuthStateListener);
    }
}

我的User.java类

package com.example.eltobgy.yala;

import java.io.Serializable;

public class User implements Serializable {
    private String id;
    private String name;
    private String phone;
    private String email;
    private String photoUrl;
    private String currentType;   //c for customer, d for delivery man
    private boolean deliveryModeActivation;
    private int rating;
    private String gender; //u:unkown, f:female, m:male
    private Birthday birthday;
    private boolean basicInfo;


    public User(String id, String name, String email) {
        this.id = id;
        this.name = name;
        this.phone = "";
        this.email = email;
        this.currentType = "";
        this.deliveryModeActivation = false;
        this.rating = 0;
        photoUrl = "";
        gender = "u";
        birthday = new Birthday(0, 0, 0);
        basicInfo = false;
    }

    public User() {

    }

    public boolean isBasicInfo() {
        return basicInfo;
    }

    public void setBasicInfo(boolean basicInfo) {
        this.basicInfo = basicInfo;
    }

    public String getGender() {
        return gender;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }

    public Birthday getBirthday() {
        return birthday;
    }

    public void setBirthday(Birthday birthday) {
        this.birthday = birthday;
    }

    public String getId() {
        return id;
    }

    public void setId(String id) {
        this.id = id;
    }

    public String getCurrentType() {
        return currentType;
    }

    public void setCurrentType(String currentType) {
        this.currentType = currentType;
    }

    public String getName() {
        return name;
    }

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

    public String getPhone() {
        return phone;
    }

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

    public String getEmail() {
        return email;
    }

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

    public String getPhotoUrl() {
        return photoUrl;
    }

    public void setPhotoUrl(String photoUrl) {
        this.photoUrl = photoUrl;
    }

    public boolean isDeliveryModeActivation() {
        return deliveryModeActivation;
    }

    public void setDeliveryModeActivation(boolean deliveryModeActivation) {
        this.deliveryModeActivation = deliveryModeActivation;
    }

    public int getRating() {
        return rating;
    }

    public void setRating(int rating) {
        this.rating = rating;
    }
}

我的数据库

在firebase数据库中保存用户的额外数据

0 个答案: