二百四十四、Hive——Hive中解析复杂JSON，既有对象还有数组，而且数组中包含数组

一、目的

由于协议修改，修改后的原始数据JSON更加复杂，导致Hive中解析的难度更大，搞了一天，还好同事发了篇知乎文章，终于得以解决，天哪，太不容易了

二、数据协议案例

{
   "deviceNo": "39",
   "sourceDeviceType": null,
   "sn": null,
   "model": null,
   "createTime": "2024-07-16 07:30:00",
   "data": {
       "cycle": 300,
       "sectionList": [{
           "sectionNo": 1,
           "coilList": [{
               "laneNo": 1,
               "laneType": null,
               "coilNo": 1,
               "volumeSum": 2,
               "volumePerson": 0,
               "volumeCarNon": 0,
               "volumeCarSmall": 2,
               "volumeCarMiddle": 0,
               "volumeCarBig": 0,
               "speedAvg": 29.65,
               "timeOccupancy": 0.63,
               "averageHeadway": 154.79,
               "averageGap": 153.49,
               "speed85": 40.0
           },
           {
               "laneNo": 2,
               "laneType": null,
               "coilNo": 2,
               "volumeSum": 5,
               "volumePerson": 0,
               "volumeCarNon": 0,
               "volumeCarSmall": 5,
               "volumeCarMiddle": 0,
               "volumeCarBig": 0,
               "speedAvg": 23.35,
               "timeOccupancy": 2.99,
               "averageHeadway": 123.27,
               "averageGap": 121.08,
               "speed85": 34.0
           },
           {
               "laneNo": 3,
               "laneType": null,
               "coilNo": 3,
               "volumeSum": 9,
               "volumePerson": 0,
               "volumeCarNon": 0,
               "volumeCarSmall": 9,
               "volumeCarMiddle": 0,
               "volumeCarBig": 0,
               "speedAvg": 26.22,
               "timeOccupancy": 4.52,
               "averageHeadway": 36.98,
               "averageGap": 35.49,
               "speed85": 36.0
           },
           {
               "laneNo": 4,
               "laneType": null,
               "coilNo": 4,
               "volumeSum": 10,
               "volumePerson": 0,
               "volumeCarNon": 0,
               "volumeCarSmall": 10,
               "volumeCarMiddle": 0,
               "volumeCarBig": 0,
               "speedAvg": 39.47,
               "timeOccupancy": 2.69,
               "averageHeadway": 34.73,
               "averageGap": 33.78,
               "speed85": 56.0
           }]
       },
       {
           "sectionNo": 2,
           "coilList": [{
               "laneNo": 5,
               "laneType": null,
               "coilNo": 5,
               "volumeSum": 1,
               "volumePerson": 0,
               "volumeCarNon": 0,
               "volumeCarSmall": 1,
               "volumeCarMiddle": 0,
               "volumeCarBig": 0,
               "speedAvg": 32.74,
               "timeOccupancy": 0.57,
               "averageHeadway": 618.59,
               "averageGap": 617.59,
               "speed85": 32.74
           },
           {
               "laneNo": 6,
               "laneType": null,
               "coilNo": 6,
               "volumeSum": 3,
               "volumePerson": 0,
               "volumeCarNon": 0,
               "volumeCarSmall": 3,
               "volumeCarMiddle": 0,
               "volumeCarBig": 0,
               "speedAvg": 39.27,
               "timeOccupancy": 0.37,
               "averageHeadway": 125.1,
               "averageGap": 124.26,
               "speed85": 49.0
           },
           {
               "laneNo": 7,
               "laneType": null,
               "coilNo": 7,
               "volumeSum": 4,
               "volumePerson": 0,
               "volumeCarNon": 0,
               "volumeCarSmall": 4,
               "volumeCarMiddle": 0,
               "volumeCarBig": 0,
               "speedAvg": 49.15,
               "timeOccupancy": 0.96,
               "averageHeadway": 91.65,
               "averageGap": 91.05,
               "speed85": 54.0
           },
           {
               "laneNo": 8,
               "laneType": null,
               "coilNo": 8,
               "volumeSum": 1,
               "volumePerson": 0,
               "volumeCarNon": 0,
               "volumeCarSmall": 1,
               "volumeCarMiddle": 0,
               "volumeCarBig": 0,
               "speedAvg": 60.2,
               "timeOccupancy": 0.17,
               "averageHeadway": 50.3,
               "averageGap": 49.7,
               "speed85": 60.2
           }]
       }]
   }
}

三、参考知乎文章链接

https://zhuanlan.zhihu.com/p/461838868

四、HiveSQL

1.首先，解析出第一层、第二层、第三层JSON

selectget_json_object(statistics_json,'$.deviceNo')          device_no,get_json_object(statistics_json,'$.sourceDeviceType')  source_device_type,get_json_object(statistics_json,'$.sn')                sn,get_json_object(statistics_json,'$.model')             model,get_json_object(statistics_json,'$.createTime')        create_time ,get_json_object(statistics_json,'$.data.cycle')        cycle,get_json_object(replace(replace(section_list,':{',':[{'),'}}','}]}'),'$.sectionNo') section_no,section_list
from hurys_dc_ods.ods_statistics
lateral view explode(split(replace(replace(replace(get_json_object(statistics_json,'$.data.sectionList'),'[',''),']',''),'},{"sectionNo"','}|{"sectionNo"'),"\\|")) tf as section_list
where day='2024-07-16'

2.然后，解析出coil_list字段里的第四层JSON

selectt1.device_no,source_device_type,sn,model,create_time,cycle,get_json_object(coil_list,'$.laneNo')  lane_no,get_json_object(coil_list,'$.laneType')           lane_type,section_no,get_json_object(coil_list,'$.coilNo')             coil_no,get_json_object(coil_list,'$.volumeSum')          volume_sum,get_json_object(coil_list,'$.volumePerson')       volume_person,get_json_object(coil_list,'$.volumeCarNon')       volume_car_non,get_json_object(coil_list,'$.volumeCarSmall')     volume_car_small,get_json_object(coil_list,'$.volumeCarMiddle')    volume_car_middle,get_json_object(coil_list,'$.volumeCarBig')       volume_car_big,get_json_object(coil_list,'$.speedAvg')           speed_avg,get_json_object(coil_list,'$.speed85')            speed_85,get_json_object(coil_list,'$.timeOccupancy')      time_occupancy,get_json_object(coil_list,'$.averageHeadway')     average_headway,get_json_object(coil_list,'$.averageGap')         average_gap,substr(create_time,1,10) day
from (selectget_json_object(statistics_json,'$.deviceNo')          device_no,get_json_object(statistics_json,'$.sourceDeviceType')  source_device_type,get_json_object(statistics_json,'$.sn')                sn,get_json_object(statistics_json,'$.model')             model,get_json_object(statistics_json,'$.createTime')        create_time ,get_json_object(statistics_json,'$.data.cycle')        cycle,get_json_object(replace(replace(section_list,':{',':[{'),'}}','}]}'),'$.sectionNo') section_no,section_list
from hurys_dc_ods.ods_statistics
lateral view explode(split(replace(replace(replace(get_json_object(statistics_json,'$.data.sectionList'),'[',''),']',''),'},{"sectionNo"','}|{"sectionNo"'),"\\|")) tf as section_list
where day='2024-07-16') as t1
lateral view explode(split(replace(replace(replace(get_json_object(replace(replace(section_list,':{',':[{'),'}}','}]}'),'$.coilList'),'[',''),']',''),'},','}|'),"\\|")) tf1 as coil_list;
;