Question

Firebase对象未写入数据库。什么是错误。。该活动正在运行，没有错误，我没有在firebase数据库中写入值。怎么做

这是我的java文件

package com.shaan.homely;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Toast;
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 com.shaan.homely.pojo.User;

import java.util.HashMap;
import java.util.Map;

public class Empty extends AppCompatActivity {

FirebaseDatabase firebaseDatabase;
DatabaseReference myref;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_empty);

    User user = new User("shaan","shaanthenapster@gmail.com","9718460374");
    myref = FirebaseDatabase.getInstance().getReference();

    String userId = myref.push().getKey();
    Map<String,User> data = new HashMap<String,User>();
    data.put(userId,user);
    //Toast.makeText(getApplicationContext(),myref.toString(),Toast.LENGTH_LONG).show();
    // creating user object
    myref.child("users").child(userId).setValue(data);

    myref.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            User user = dataSnapshot.getValue(User.class);
            Toast.makeText(getApplicationContext(),user.getEmail()+user.getName(),Toast.LENGTH_LONG).show();
        }

        @Override
        public void onCancelled(DatabaseError databaseError) {
            Toast.makeText(getApplicationContext(),"Error",Toast.LENGTH_LONG).show();
        }
    });

    myref.addChildEventListener(new ChildEventListener() {
        @Override
        public void onChildAdded(DataSnapshot dataSnapshot, String s) {
            User user = dataSnapshot.getValue(User.class);
            Toast.makeText(getApplicationContext(),user.getEmail()+user.getName(),Toast.LENGTH_LONG).show();
        }

        @Override
        public void onChildChanged(DataSnapshot dataSnapshot, String s) {

        }

        @Override
        public void onChildRemoved(DataSnapshot dataSnapshot) {

        }

        @Override
        public void onChildMoved(DataSnapshot dataSnapshot, String s) {

        }

        @Override
        public void onCancelled(DatabaseError databaseError) {
            Toast.makeText(getApplicationContext(),"Error",Toast.LENGTH_LONG).show();

        }
    });

}
}

这是我的用户类

package com.shaan.homely.pojo;

import com.google.firebase.database.IgnoreExtraProperties;

@IgnoreExtraProperties
public class User {

public String name;
public String email;
public String mobile;

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 getMobile() {
    return mobile;
}

public void setMobile(String mobile) {
    this.mobile = mobile;
}


// Default constructor required for calls to
// DataSnapshot.getValue(User.class)
public User() {
}

public User(String name, String email, String mobile) {
    this.name = name;
    this.email = email;
    this.mobile = mobile;
}
}

Answer 1

您将值推送到根数据库，然后在子用户＆＃39;中查找它。您的初步参考必须指向孩子的用户＆＃39; ，您希望创建新条目：

 myref = FirebaseDatabase.getInstance().getReference().child("users");

String userId = myref.push().getKey();
Map<String,User> data = new HashMap<String,User>();
data.put(userId,user);
//Toast.makeText(getApplicationContext(),myref.toString(),Toast.LENGTH_LONG).show();
// creating user object
myref.child(userId).setValue(data);

<强>更新

您也在推送一个hashmap，但随后又读了一个User类。我建议你将id添加到User类而不是创建hashmap：

public class User {
    ...
    private String userId;

    public String getUserId() {
        return userId;
    }

    public void setUserId(String userId) {
        this.userId = userId;
    }
}

在您的代码中：

String userId = myref.push().getKey();
user.setUserId(userId);

// creating user object
myref.child("users").child(userId).setValue(user);

Firebase对象未写入数据库

1 个答案: