在改造中从响应主体中获取一个数据

Question

{
    "statusCode": 200,
    "message": "Data",
    "data": [
        {
            "gtinNumber": "18903840000840",
            "batchNumber": "18222009",
            "consignmentNumber": "54782136548",
            "manufacturerName": null,
            "manufacturingDate": "30/09/2017",
            "experyDate": "30/09/2019",
            "fromSerialNumber": "100120",
            "toSerialNumber": "1000100",
            "concatFromSerialNumber": null,
            "concatToSerialNumber": "1000100NDADBLR10032",
            "date": "2018-09-15_14:17:42",
            "assignStatus": "assigned",
            "addDistributers": [
                {
                    "distributorId": "NDADBLR10032",
                    "distributorLocation": "Bangalore-BLR",
                    "receivedtime": "2018-09-17_09:08:47",
                    "packageStatus": "received",
                    "assignStatus": "notAssigned"
                }
            ]
        }
    ]
}

我总是出错：

  

java.lang.ClassCastException：com.google.gson.internal.LinkedTreeMap   无法转换为in.appface.ndaqrcodemanager.data

我只想从中取出assignStatus