java - Firebase 数据库异常无法将 long 转换为 String

Question

我正在使用 Firebase 实时数据库，但收到以下错误

FATAL EXCEPTION: main
                                                                    Process: com.example.tobias.run, PID: 17405
                                                                    com.google.firebase.database.DatabaseException: Failed to convert value of type java.lang.Long to String
                                                                        at com.google.android.gms.internal.zzbtg.zzaG(Unknown Source)
                                                                        at com.google.android.gms.internal.zzbtg.zzb(Unknown Source)
                                                                        at com.google.android.gms.internal.zzbtg.zza(Unknown Source)
                                                                        at com.google.android.gms.internal.zzbtg.zzb(Unknown Source)
                                                                        at com.google.android.gms.internal.zzbtg$zza.zze(Unknown Source)
                                                                        at com.google.android.gms.internal.zzbtg$zza.zzaH(Unknown Source)
                                                                        at com.google.android.gms.internal.zzbtg.zze(Unknown Source)
                                                                        at com.google.android.gms.internal.zzbtg.zzb(Unknown Source)
                                                                        at com.google.android.gms.internal.zzbtg.zza(Unknown Source)
                                                                        at com.google.firebase.database.DataSnapshot.getValue(Unknown Source)
                                                                        at com.example.tobias.run.history.HistoryFragment$2.onChildAdded(HistoryFragment.java:123)
                                                                        at com.google.android.gms.internal.zzbox.zza(Unknown Source)
                                                                        at com.google.android.gms.internal.zzbqx.zzZV(Unknown Source)
                                                                        at com.google.android.gms.internal.zzbra$1.run(Unknown Source)
                                                                        at android.os.Handler.handleCallback(Handler.java:751)
                                                                        at android.os.Handler.dispatchMessage(Handler.java:95)
                                                                        at android.os.Looper.loop(Looper.java:241)
                                                                        at android.app.ActivityThread.main(ActivityThread.java:6274)
                                                                        at java.lang.reflect.Method.invoke(Native Method)
                                                                        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
                                                                        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)

当我尝试将从数据库检索的数据编码到类中时。错误发生在这里

databaseRef.addChildEventListener(new ChildEventListener() {
        @Override
        public void onChildAdded(DataSnapshot dataSnapshot, String s) {
            dataSnapshot.getValue(TrackedRun.class);
        }

跟踪运行类(class)

public class TrackedRun implements Parcelable {

private float mDistance;
private long mTime;
private long mDate;
private int mRating;
private String mUnit;
private Integer mID = null;

public TrackedRun(int id, long date, float distance, long time, int rating, String unit){
    this.mDistance = distance;
    this.mTime = time;
    this.mDate = date;
    this.mRating = rating;
    this.mUnit = unit;
    this.mID = id;
}


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

public TrackedRun(Parcel in) {
    this.mID = in.readInt();
    this.mDate = in.readLong();
    this.mDistance = in.readFloat();
    this.mTime = in.readLong();
    this.mRating = in.readInt();
    this.mUnit = in.readString();
}

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

@Override
public void writeToParcel(Parcel parcel, int i) {
    parcel.writeInt(mID);
    parcel.writeLong(mDate);
    parcel.writeFloat(mDistance);
    parcel.writeLong(mTime);
    parcel.writeInt(mRating);
    parcel.writeString(mUnit);
}

@Exclude
public static final Parcelable.Creator<TrackedRun> CREATOR = new Parcelable.Creator<TrackedRun>(){

    @Override
    public TrackedRun createFromParcel(Parcel parcel) {
        return new TrackedRun(parcel);
    }

    @Override
    public TrackedRun[] newArray(int i) {
        return new TrackedRun[i];
    }
};

public float getDistance(){
    return mDistance;
}
public long getTime(){
    return mTime;
}
public long getDate(){ return mDate; }
public int getRating(){
    return mRating;
}
public String getUnit(){
    return mUnit;
}
public Integer getId(){ return mID; }


public void setDistance(String distance){
    mDistance = DateManager.distanceToFloat(distance);
}
public void setTime(String time){
    mTime = DateManager.timeToUnix(time);
}
public void setDate(String date){
    mDate = DateManager.dateToUnix(date);
}
public void setRating(String rating){
    mRating = Integer.valueOf(rating);
}

public void setUnit(String unit){
    mUnit = unit;
}

Firebase database structure

我尝试更改必须 int 的两个长字段，但出现了完全相同的错误。这与我正在实现 Parcelable 有关吗？此外，当我运行 dataSnapshot.getValue().toString() 时，所有字段都以正确的数据类型存在。

Answer 1

您的setter方法的参数类型与数据库中的值不一致。例如:

public void setRating(String rating) {
    mRating = Integer.valueOf(rating);
}

这会导致 Firebase 需要数据库中的字符串值来进行评级。它找到一个 Long 值并报告它无法将 Long 转换为 setRating() 所需的字符串。 setDistance()、setTime() 和 setDate() 也存在同样的问题。

更改参数类型或数据库值以保持一致。