1.JsonArray
[{"iSubdomainId":0,"iUpdate":0,"sHtDescription":"","sSourceId":1,"iSource":0,"iHour":0,"sSubdomainName":"","dHtDate":"","iOcLevel":0,"dCheckTime":"2023-02-24 12:38:10","iBuildProject":0,"sHtName":"","iOcNum":0,"iRepairType":0,"iMaintenance":0,"sReportUser":"","sUpdateTime":"2023-02-24 12:38:10","sDomainName":"","iId":0,"iOcWay":0,"dCreateTime":"2023-02-24 12:38:10","sUpdateUser":"","sCheckUser":"","iDomainId":0,"iMcId":0,"iHtId":0,"iHtType":0,"sMcName":""},{"iSubdomainId":0,"iUpdate":0,"sHtDescription":"","sSourceId":2,"iSource":0,"iHour":0,"sSubdomainName":"","dHtDate":"","iOcLevel":0,"dCheckTime":"2023-02-24 12:38:10","iBuildProject":0,"sHtName":"","iOcNum":0,"iRepairType":0,"iMaintenance":0,"sReportUser":"","sUpdateTime":"2023-02-24 12:38:10","sDomainName":"","iId":0,"iOcWay":0,"dCreateTime":"2023-02-24 12:38:10","sUpdateUser":"","sCheckUser":"","iDomainId":0,"iMcId":0,"iHtId":0,"iHtType":0,"sMcName":""},{"iSubdomainId":0,"iUpdate":0,"sHtDescription":"","sSourceId":3,"iSource":0,"iHour":0,"sSubdomainName":"","dHtDate":"","iOcLevel":0,"dCheckTime":"2023-02-24 12:38:10","iBuildProject":0,"sHtName":"","iOcNum":0,"iRepairType":0,"iMaintenance":0,"sReportUser":"","sUpdateTime":"2023-02-24 12:38:10","sDomainName":"","iId":0,"iOcWay":0,"dCreateTime":"2023-02-24 12:38:10","sUpdateUser":"","sCheckUser":"","iDomainId":0,"iMcId":0,"iHtId":0,"iHtType":0,"sMcName":""}]
com.alibaba.fastjson.JSONArray jsonArray1 = JSON.parseArray(map.get("maintenanceData"));
com.alibaba.fastjson.JSONArray jsonArray2 = com.alibaba.fastjson.JSONArray.parseArray(map.get("maintenanceData"));
System.out.println(jsonArray1.size());
System.out.println(jsonArray1);
System.out.println(jsonArray2.size());
System.out.println(jsonArray2);