Jasper Report JSON 数组字段在 Detail Band 中显示为数组

Question

我正在 Jaspersoft Studio 中做一份 Jasper Report，我添加了一个 JSON 文件作为数据源。当我将字段拖到详细信息带中并在预览中查看它时，它在文本中显示为数组。

我的 JSON 文件是：

{
"billingLineCharges": [
        {
            "netAmt": 50,
            "billingLineChargeDets": [
                {
                    "chargeType": "ADHOC",
                    "active": true,
                    "chargeDets": [
                        {
                            "bill_uom": "PJ",
                            "tax_desc": "ADD GST @ 7%",
                            "charge_type": "ADHOC",
                            "tax_code": "7% OUTPUT TAX",
                            "unit_rate": 50,
                            "bill_qty": 1,
                            "charge_amt": 50,
                            "billing_doc_id": 1,
                            "id": 2
                        }
                    ],
                    "blcdId": 1,
                    "version": 0,
                    "chargeDetId": 2,
                    "billingLineChargeId": 1
                }
            ],
            "blcId": 1,
            "taxInd": false,
            "active": true,
            "currency": [
                {
                    "code": "SGD",
                    "name": "Singapore dollar"
                }
            ],
            "currId": 133,
            "version": 0,
            "billingDocId": 1,
            "billingLineDesc": "RESTACK"
        },
        {
            "netAmt": 3.5,
            "billingLineChargeDets": [
                {
                    "chargeType": "TAX",
                    "active": true,
                    "chargeDets": [
                        {
                            "bill_uom": "PJ",
                            "tax_desc": "ADD GST @ 7%",
                            "charge_type": "TAX",
                            "tax_code": "7% OUTPUT TAX",
                            "unit_rate": 5,
                            "bill_qty": 2,
                            "charge_amt": 3.5,
                            "billing_doc_id": 1,
                            "id": 3
                        }
                    ],
                    "blcdId": 2,
                    "version": 0,
                    "chargeDetId": 3,
                    "billingLineChargeId": 2
                }
            ],
            "blcId": 2,
            "taxInd": true,
            "active": true,
            "currency": [
                {
                    "code": "SGD",
                    "name": "Singapore dollar"
                }
            ],
            "currId": 133,
            "version": 0,
            "billingDocId": 1,
            "billingLineDesc": "ADD GST @ 7%"
        }
}

我正在尝试将 billingLineDesc 显示到详细信息带中。

我希望它像一排排桌子。

RESTACK ADD GST @ 7%

但我看到的是：

["RESTACK","ADD GST @ 7%"]

请告诉我哪里出了问题？谢谢。