One-to-many query results are displayed when mybatis query

<resultMap type="com.medical.design.vo.MContractVo" id="mContractTestMap">
		<result property="id" column="id" />
		<collection property="contractProductList" ofType="com.medical.design.entity.MContractProduct">
			<result property="id" column="id" />
			<result property="productName" column="product_name" />
			<result property="productSku" column="product_sku" />
			<result property="productQuantity" column="product_quantity" />
			<result property="productUnit" column="product_unit" />
		</collection>
	</resultMap>

@Data
public class MContractVo {
    private Integer	id;		 /* 自增id */
    private String  companyName;     /* 公司名称 */
    private String title;        /* 需求名称 */
    private List<MContractProduct>   contractProductList;
}

{
    "rows": [],
    "total": 0,
    "data": [
        {
            "id": 124,
            "companyName": "ceshi",
            "title": null
            "contractProductList": [
                {
                    "id": 124,
                    "productName": "ceshi",
                    "productSku": "ceshi1",
                    "productQuantity": 123,
                    "productUnit": "dun",
                    "createTime": "2020-08-27 23:23:34",
                    "modifyTime": "2020-08-28 17:30:50"
                },
                {
                    "id": 124,
                    "productName": "ceshi2",
                    "productSku": "ceshi2",
                    "productQuantity": 321,
                    "productUnit": "dun",
                    "createTime": "2020-08-27 23:23:34",
                    "modifyTime": "2020-08-28 17:30:50"
                }
            ]
        }
    ],
    "message": "",
    "success": true
}