我一直在嘗試瞭解Firebase,在我的第一個示例中存在一個我根本不理解的錯誤。如果有人能幫助我,我會很感激Firebase未知屬性異常
THIS IS MY MAINACTIVITY.JAVA
package com.example.betterlaylow.firebasetestinsertretrieve;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import com.firebase.client.DataSnapshot;
import com.firebase.client.Firebase;
import com.firebase.client.FirebaseError;
import com.firebase.client.ValueEventListener;
import java.util.HashMap;
import java.util.Map;
public class MainActivity extends AppCompatActivity {
private EditText editTextName;
private EditText editTextAddress;
private TextView textViewPersons;
private Button buttonSave;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Firebase.setAndroidContext(this);
buttonSave = (Button) findViewById(R.id.buttonSave);
editTextName = (EditText) findViewById(R.id.editTextName);
editTextAddress = (EditText) findViewById(R.id.editTextAddress);
textViewPersons = (TextView) findViewById(R.id.textViewPersons);
//Click Listener for button
buttonSave.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//Creating firebase object
Firebase ref = new Firebase(Config.FIREBASE_URL);
//Getting values to store
String name = editTextName.getText().toString().trim();
String address = editTextAddress.getText().toString().trim();
//Creating Person object
Person person = new Person();
//Adding values
person.setName(name);
person.setAddress(address);
//Storing values to firebase
ref.child("Person").setValue(person);
//Value event listener for realtime data update
ref.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot snapshot) {
for (DataSnapshot postSnapshot : snapshot.getChildren()) {
//Getting the data from snapshot
Person person = postSnapshot.getValue(Person.class);
//Adding it to a string
String string = "Name: "+person.getName()+"\nAddress: "+person.getAddress()+"\n\n";
//Displaying it on textview
textViewPersons.setText(string);
}
}
@Override
public void onCancelled(FirebaseError firebaseError) {
System.out.println("The read failed: " + firebaseError.getMessage());
}
});
}
});
}
}
THIS IS MY PERSON.JAVA
package com.example.betterlaylow.firebasetestinsertretrieve;
/**
* Created by betterlaylow on 7/26/16.
*/
public class Person {
//name and address string
private String name;
private String address;
public Person() {
/*Blank default constructor essential for Firebase*/
}
//Getters and setters
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
}
THIS IS MY CONFIG.JAVA
package com.example.betterlaylow.firebasetestinsertretrieve;
/**
* Created by betterlaylow on 7/26/16.
*/
public class Config {
public static final String FIREBASE_URL = "https://simplifiedcoding.firebaseio.com/";
}
AND THIS ID ANDROID MONITOR
07-26 21:07:06.917 6408-6408/com.example.betterlaylow.firebasetestinsertretrieve E/AndroidRuntime:致命例外:main 進程:com.example.betterlaylow.firebasetestinsertretrieve,PID:6408 com.firebase.client。 FirebaseException:無法彈出以在com.firebase.client.DataSnapshot.getValue(DataSnapshot.java:185) 處鍵入 at com.example.betterlaylow.firebasetestinsertretrieve.MainActivity $ 1 $ 1.onDataChange(MainActivity.java:66) at com .firebase.client.core.ValueEventRegistration.fireEvent(ValueEventRegistration.java:45) at com.firebase.client.core.view.DataEvent.fire(DataEvent.java:45) at com.firebase.client.core.view.EventRaiser $ 1.run(EventRaiser.java:38) at android.os.Handler.handleCallback(Handler.java:739) at android.os.Handler.dispatchMessage(Handler .java:95) at android.os.Looper.loop(Looper.java:148) at android.app.ActivityThread.main(ActivityThread.java:5417) at java.lang.reflect.Method.invoke(Native COM:方法) 在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run(ZygoteInit.java:726) 在com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616) 所致。 fasterxml.jac kson.databind.exc.UnrecognizedPropertyException:無法識別的字段「msg」(com.example.betterlaylow.firebasetestinsertretrieve.Person類),未標記爲可忽略(2個已知屬性:,「地址」,「名稱」]) at [Source: [email protected];行:1,列:9](通過引用鏈:com.example.betterlaylow.firebasetestinsertretrieve.Person [「msg」]) at com.fasterxml.jackson.databind.DeserializationContext.reportUnknownProperty(DeserializationContext.java:555) at com.fasterxml.jackson.databind.deser.std.StdDeserializer.handleUnknownProperty(StdDeserializer.java:708) at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.handleUnknownProperty(BeanDeserializerBase.java:1160) at com.fasterxml。 jackson.databind.deser.BeanDeserializer.deserializeFromObject(BeanDeserializer.java:315) at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:121) at com.f asterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:2888) at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:2034) at com.firebase.client.DataSnapshot.getValue(DataSnapshot。 java:183) at com.example.betterlaylow.firebasetestinsertretrieve。MainActivity $ 1 $ 1.onDataChange(MainActivity.java:66) at com.firebase.client.core.ValueEventRegistration.fireEvent(ValueEventRegistration.java:45) at com.firebase.client.core.view.DataEvent.fire(DataEvent。 java:45) at com.firebase.client.core.view.EventRaiser $ 1.run(EventRaiser.java:38) at android.os.Handler.handleCallback(Handler.java:739) at android.os.Handler .dispatchMessage(Handler.java:95) at android.os.Looper.loop(Looper.java:148) at android.app.ActivityThread.main(ActivityThread.java:5417) at java.lang.reflect.Method 。在voke(本機方法) 在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run(ZygoteInit.java:726) 在com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)