从Firebase实时数据库中读取应用程序时崩溃

问题描述：

我想读取Firebase实时数据库中的所有元素（通过导入.json文件（未使用我的应用程序填充）填充所有元素。因此，我尝试了很多其他解决方案但他们没有工作，这是我的实时数据库：从Firebase实时数据库中读取应用程序时崩溃

这里是我阅读的主要活动的数据：

public final ArrayList<Parking> parkingArrayList=new ArrayList<Parking>(); 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 
    FirebaseDatabase firebaseDatabase=FirebaseDatabase.getInstance(); 
    firebaseDatabase.setPersistenceEnabled(true); 
    DatabaseReference databaseReference=firebaseDatabase.getReference(); 
    databaseReference.child("Parking").addListenerForSingleValueEvent(new ValueEventListener() { 
     @Override 
     public void onDataChange(DataSnapshot dataSnapshot) { 
      for(DataSnapshot dataSnapshot1:dataSnapshot.getChildren()){ 
      Parking p=dataSnapshot1.getValue(Parking.class); 
      } 
     } 

     @Override 
     public void onCancelled(DatabaseError databaseError) { 

     } 
    });

这里是我的停车类：

public class Parking implements Comparable<Parking>,Parcelable { 
public String name; 
public String zone; 
public String location; 
public int capacity; 
public double latitude; 
public double longtitude; 
int free=0; 
int taken=0; 
int id; 
public Parking(){ 
} 
public Parking(int capacity,double latitude,String location, double longtitude,String name,String zone){ 
    this.capacity=capacity; 
    this.location=location; 
    this.name=name; 
    this.zone=zone; 
    this.latitude=latitude; 
    this.longtitude=longtitude; 
    this.taken=getTaken(); 
    this.free=getFree(); 
} 

protected Parking(Parcel in) { 
    name = in.readString(); 
    zone = in.readString(); 
    location = in.readString(); 
    capacity = in.readInt(); 
    latitude = in.readDouble(); 
    longtitude = in.readDouble(); 
    free = in.readInt(); 
    taken = in.readInt(); 
} 

public static final Creator<Parking> CREATOR = new Creator<Parking>() { 
    @Override 
    public Parking createFromParcel(Parcel in) { 
     return new Parking(in); 
    } 

    @Override 
    public Parking[] newArray(int size) { 
     return new Parking[size]; 
    } 
}; 

public int getCapacity() { 
    return capacity; 
} 

public int getFree() { 
    return capacity-getTaken(); 
} 

public int getTaken() { 
    Random random=new Random(); 
    this.taken=random.nextInt(capacity+1); 
    return taken; 
} 

public void setFree(int taken){ 
    free=capacity-taken; 
} 
public void setTaken(int taken) { 
    Random random=new Random(); 
    this.taken=random.nextInt(capacity+1); 
} 
public double getLatitude(){ 
    return latitude; 
} 
public double getLongtidue(){ 
    return longtitude; 
} 


@Override 
public String toString() { 
    return String.format("%s\t\tZone: %s\nlocation: %s\nCapacity: %d\t\tFree: %d",name,zone,location,capacity,getFree()); 
} 


@Override 
public int compareTo(@NonNull Parking parking) { 
    return Integer.compare(parking.free,this.free); 
} 

@Override 
public int describeContents() { 
    return 0; 
} 

@Override 
public void writeToParcel(Parcel parcel, int i) { 
    parcel.writeInt(capacity); 
    parcel.writeDouble(latitude); 
    parcel.writeString(location); 
    parcel.writeDouble(longtitude); 
    parcel.writeString(name); 
    parcel.writeString(zone); 
    parcel.writeInt(getTaken()); 
    parcel.writeInt(getFree()); 
}

}

我与火力地堡连接它，安装谷歌-services.json文件（通过使用火力工具），但是当我开始崩溃的应用程序（“不幸的是，najdiparking（我的应用程序名称）已经停止）。当我手动填写列表（不从数据库读取）时，应用程序可以正常工作。这是依赖关系的com.google.firebase：firebase-database：10.0.1。

我也检查我的.json文件名与类中的名称。

我logcat的（我希望这将帮助你）

08-27 15:41:31.884 19384-19384/com.example.simeon.najdiparking E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.simeon.najdiparking, PID: 19384 java.lang.NoSuchMethodError: No virtual method zzTt()Z in class Lcom/google/firebase/FirebaseApp; or its super classes (declaration of 'com.google.firebase.FirebaseApp' appears in /data/app/com.example.simeon.najdiparking-1/split_lib_dependencies_apk.apk:classes20.dex) at com.google.firebase.database.FirebaseDatabase.getInstance(Unknown Source) at com.google.firebase.database.FirebaseDatabase.getInstance(Unknown Source) at com.example.simeon.najdiparking.MainActivity.onCreate(MainActivity.java:48) at android.app.Activity.performCreate(Activity.java:6237) at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1107) at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2369) at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2476) at android.app.ActivityThread.-wrap11(ActivityThread.java) at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1344) at android.os.Handler.dispatchMessage(Handler.java:102) at android.os.Looper.loop(Looper.java:148) at android.app.ActivityThread.main(ActivityThread.java:5417) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

您可以提供日志以更好地了解您的问题 – Sergey

发布logcat错误。 –

看起来您复制了logcat的错误部分。 –

答

你必须从包裹在你写它thesame顺序读取。

从Firebase实时数据库中读取应用程序时崩溃

相关推荐