用列表的映射解析 JSON

Question

我是 scala 和 JSON 解析的新手，需要一些帮助。我需要解析复杂的 JSON（如下）以获取 "dimension" 键中 "name" 的值，即我需要 PLATFORM 和 OS_VERSION.

我尝试了多种选择，但都不行。感谢任何帮助

这是我试过的代码片段，但我无法继续解析列表。我认为 'ANY' 关键字导致了一些不匹配/问题。

import org.json4s._
import org.json4s.jackson.JsonMethods._

implicit val formats = org.json4s.DefaultFormats

val mapJSON = parse(tmp).extract[Map[String, Any]]
println(mapJSON)

//for ((k,v) <- mapJSON) printf("key: %s, value: %s\n", k, v)

val list_map = mapJSON("dimensions")

{
  "uuid": "uuidddd",
  "last_modified": 1559080222953,
  "version": "2.6.1.0",
  "name": "FULL_DAY_2_mand_date",
  "is_draft": false,
  "model_name": "FULL_DAY_1_may05",
  "description": "",
  "null_string": null,
  "dimensions": [
    {
      "name": "PLATFORM",
      "table": "tbl1",
      "column": "PLATFORM",
      "derived": null
    },
    {
      "name": "OS_VERSION",
      "table": "tbl1",
      "column": "OS_VERSION",
      "derived": null
    },
  ],
  "measures": [
    {
      "name": "_COUNT_",
      "function": {
        "expression": "COUNT",
        "parameter": {
          "type": "constant",
          "value": "1"
        },
        "returntype": "bigint"
      }
    },
    {
      "name": "UU",
      "function": {
        "expression": "COUNT_DISTINCT",
        "parameter": {
          "type": "column",
          "value": "tbl1.USER_ID"
        },
        "returntype": "hllc(12)"
      }
    },
    {
      "name": "CONT_SIZE",
      "function": {
        "expression": "SUM",
        "parameter": {
          "type": "column",
          "value": "tbl1.SIZE"
        },
        "returntype": "bigint"
      }
    },
    {
      "name": "CONT_COUNT",
      "function": {
        "expression": "SUM",
        "parameter": {
          "type": "column",
          "value": "tbl1.COUNT"
        },
        "returntype": "bigint"
      }
    }
  ],
  "dictionaries": [],
  "rowkey": {
    "rowkey_columns": [
      {
        "column": "tbl1.OS_VERSION",
        "encoding": "dict",
        "encoding_version": 1,
        "isShardBy": false
      },
      {
        "column": "tbl1.PLATFORM",
        "encoding": "dict",
        "encoding_version": 1,
        "isShardBy": false
      },
      {
        "column": "tbl1.DEVICE_FAMILY",
        "encoding": "dict",
        "encoding_version": 1,
        "isShardBy": false
      }
    ]
  },
  "hbase_mapping": {
    "column_family": [
      {
        "name": "F1",
        "columns": [
          {
            "qualifier": "M",
            "measure_refs": [
              "_COUNT_",
              "CONT_SIZE",
              "CONT_COUNT"
            ]
          }
        ]
      },
      {
        "name": "F2",
        "columns": [
          {
            "qualifier": "M",
            "measure_refs": [
              "UU"
            ]
          }
        ]
      }
    ]
  },
  "aggregation_groups": [
    {
      "includes": [
        "tbl1.PLATFORM",
        "tbl1.OS_VERSION"
      ],
      "select_rule": {
        "hierarchy_dims": [],
        "mandatory_dims": [
          "tbl1.DATE_HR"
        ],
        "joint_dims": []
      }
    }
  ],
  "signature": "ttrrs==",
  "notify_list": [],
  "status_need_notify": [
    "ERROR",
    "DISCARDED",
    "SUCCEED"
  ],
  "partition_date_start": 0,
  "partition_date_end": 3153600000000,
  "auto_merge_time_ranges": [
    604800000,
    2419200000
  ],
  "volatile_range": 0,
  "retention_range": 0,
  "engine_type": 4,
  "storage_type": 2,
  "override_kylin_properties": {
    "job.queuename": "root.production.P0",
    "is-mandatory-only-valid": "true"
  },
  "cuboid_black_list": [],
  "parent_forward": 3,
  "mandatory_dimension_set_list": [],
  "snapshot_table_desc_list": []
}

Answer 1

您需要更具体地类来解析数据，如下所示：

case class Dimension(name: String, table: String, column: String)
case class AllData(uuid: String, dimensions: List[Dimension])

val data = parse(tmp).extract[AllData]
val names = data.dimensions.map(_.name)

用列表的映射解析 JSON

Parse JSON with map of list

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