android 开发Parcelable 怎么传值ArrayList

public class TradeEntity implements Parcelable{
    public String id;

    //有关进度条的参数
    ArrayList<TradeStateNodeInfo> nodes;
    public TradeEntity() {
        nodes = new ArrayList<TradeStateNodeInfo>();
    }
    /////////////////////////实现parcel接口///////////////////////////////
    @Override
    public int describeContents() {
        return 0;
    }
    @Override
    public void writeToParcel(Parcel out, int arg1) {
        out.writeString(id);
        out.writeList(nodes);
    }
    private TradeEntity(Parcel in)
    {
        id = in.readString();
        nodes = in.readArrayList(TradeStateNodeInfo.class.getClassLoader());
    }
    public static final Parcelable.Creator<TradeEntity> CREATOR = new Parcelable.Creator<TradeEntity>()
    {
        public TradeEntity createFromParcel(Parcel in)
        {
            return new TradeEntity(in);
        }

        public TradeEntity[] newArray(int size)
        {
            return new TradeEntity[size];
        }
    };
}