Jolt转换嵌套数组JSON时子数组元素错乱问题求助

问题说明 #

作为Jolt新手，处理包含嵌套数组的JSON转换时，发现父级的子数组times元素出现跨父级混淆：id为1的对象混入了id为2的times元素，id为2的对象混入了id为1的times元素，预期每个父级对象的timing数组应仅包含自身opening数组对应的元素。

输入JSON #

[
  {
    "id": "1",
    "name": "data1",
    "opening": [
      {
        "From": "07:30:01",
        "To": "17:30:01"
      },
      {
        "From": "07:30:02",
        "To": "17:30:02"
      }
    ]
  },
  {
    "id": "2",
    "name": "data2",
    "opening": [
      {
        "From": "07:30:03",
        "To": "17:30:03"
      },
      {
        "From": "07:30:04",
        "To": "17:30:04"
      }
    ]
  }
]

原Jolt转换规则 #

[
  {
    "operation": "shift",
    "spec": {
      "*": {
        "id": "[&1].id",
        "name": "[&1].name",
        "opening": {
          "*": {
            "From": "[&1].timing.[&3].times[0].from",
            "To": "[&1].timing.[&3].times[0].to"
          }
        }
      }
    }
  }
]

预期输出 #

[ {
  "id" : "1",
  "name" : "data1",
  "timing" : [ {
    "times" : [ {
      "from" : "07:30:01",
      "to" : "17:30:01"
    } ]
  }, {
    "times" : [ {
      "from" : "07:30:02",
      "to" : "17:30:02"
    } ]
  } ]
}, {
  "timing" : [ {
    "times" : [ {
      "from" : "07:30:03",
      "to" : "17:30:03"
    } ]
  }, {
    "times" : [ {
      "from" : "07:30:04",
      "to" : "17:30:04"
    } ]
  } ],
  "id" : "2",
  "name" : "data2"
} ]

当前错误输出 #

[ {
  "id" : "1",
  "name" : "data1",
  "timing" : [ {
    "times" : [ {
      "from" : "07:30:01",
      "to" : "17:30:01"
    } ]
  }, {
    "times" : [ {
      "from" : "07:30:03",
      "to" : "17:30:03"
    } ]
  } ]
}, {
  "timing" : [ {
    "times" : [ {
      "from" : "07:30:02",
      "to" : "17:30:02"
    } ]
  }, {
    "times" : [ {
      "from" : "07:30:04",
      "to" : "17:30:04"
    } ]
  } ],
  "id" : "2",
  "name" : "data2"
} ]

修正方案 #

错误原因 #

原规则中From和To的路径使用了错误的层级引用：[&1].timing.[&3]把当前opening元素的索引当作了父数组的索引，把父元素的索引当作了timing数组的索引，导致不同父级的opening元素被错误映射到其他父级的timing数组中。

修正后的Jolt规则 #

[
  {
    "operation": "shift",
    "spec": {
      "*": {
        "id": "[&1].id",
        "name": "[&1].name",
        "opening": {
          "*": {
            "From": "[&3].timing.[&1].times[0].from",
            "To": "[&3].timing.[&1].times[0].to"
          }
        }
      }
    }
  }
]

规则解释 #

• [&3]：在opening的子元素层级，引用最外层父元素的索引，确保每个父级对象的属性被映射到自身数组位置
• [&1]：引用当前opening数组元素的索引，确保每个opening元素被映射到当前父级timing数组的对应位置

这样每个父级对象的opening数组元素会被正确映射到自身的timing数组中，不会出现跨父级混淆。

内容的提问来源于stack exchange，提问作者dawood