从Firebase读取数据时未识别的PropertyException

Question

我正在尝试读取存储在Firebase数据库中的值。这就是数据库的样子：

URL:https://xxxx.firebaseio.com/comesion/passes/away/assenal

现在，从Android端，这就是我尝试检索数据的方式：

    Firebase mRef = new Firebase("https://xxxx.firebaseio.com/Cohesion/Passes/Away/Arsenal");

    mRef.addValueEventListener(new ValueEventListener()
    {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot)
        {
            Arsenal vals = dataSnapshot.getValue(Arsenal.class);
            Log.e("retValue",""+vals);

        }

        @Override
        public void onCancelled(FirebaseError firebaseError)
        {
            Log.e("REAL_ERROR",""+firebaseError);

        }
    });

public class Arsenal {

    private int Cross;
    private int LongBall;
    private int ShortPass;
    private int ThroughBall;

    public Arsenal()
    {

    }

    public Arsenal(int Cross,int LongBall,int ShortPass,int ThroughBall)
    {
        this.Cross = Cross;
        this.LongBall = LongBall;
        this.ShortPass = ShortPass;
        this.ThroughBall = ThroughBall;
    }
    public int getCross() {
        return Cross;
    }


    public int getLongBall() {
        return LongBall;
    }


    public int getShortPass() {
        return ShortPass;
    }


    public int getThroughBall() {
        return ThroughBall;
    }


}

Answer 1

当Firebase发现一个具有getter和setter的类时，Firebase使用JavaBean命名约定来确定底层的JSON属性名称。

这意味着

public class Arsenal {
    private int Cross;

    public int getCross() {
        return Cross;
    }
}

转换为以下JSON：

cross: 19

cross: 19

public class Arsenal {
    public int Cross;
}

public class Arsenal {
    private int Cross;

    @JsonProperty("Cross")
    public int getCross() {
        return Cross;
    }
}

在Firebase3.x中，对应的注释是PropertyName:

public class Arsenal {
    private int Cross;

    @PropertyName("Cross")
    public int getCross() {
        return Cross;
    }
}