我正在尝试使用apache nifi中的jolttransformrecord将JSON转换为JSON。当我尝试在https://jolt-demo.appspot.com/中转换JSON时，我会得到正确的结果。这是Okey。
但是，当我尝试使用jolttransformrecord转换JSON时，它会引发异常。错误是；"无法转换类[ljava.lang.object;由于不支持类型的值。但是我不明白为什么我会遇到这个错误。我确实检查了我的输入和输出模式，但没有找到任何东西。他们看起来是正确的。
在下面，给出了我的输入和输出JSON示例，震动规范，输入和输出模式。另外，为此，我正在使用 JSONTREEREDER 和 JSONRECORDSETWRITER 。
---我该如何解决这个问题？---
示例输入json for JoltTransformRecord（在此示例中，数组中只有一个JSON对象。但是实际上，数组中有很多JSON对象。）;
[ {
"uuid" : "MFMS1-MC5",
"componentId" : "path1",
"Samples" : {
"PathFeedrate" : [ {
"dataItemId" : "pf",
"timestamp" : "2019-03-01T21:48:27.940558Z",
"sequence" : "68104",
"value" : "425.5333",
"name" : "Fact",
"subType" : "ACTUAL"
}, {
"dataItemId" : "pf",
"timestamp" : "2019-03-01T21:48:30.244219Z",
"sequence" : "68117",
"value" : "0",
"name" : "Fact",
"subType" : "ACTUAL"
} ]
},
"Events" : {
"SequenceNumber" : [ {
"dataItemId" : "seq",
"timestamp" : "2019-03-01T21:48:27.940558Z",
"sequence" : "68105",
"value" : "0",
"name" : "sequenceNum"
} ],
"Unit" : [ {
"dataItemId" : "unit",
"timestamp" : "2019-03-01T21:48:27.940558Z",
"sequence" : "68106",
"value" : "13",
"name" : "unitNum"
} ]
}
}]
示例输出JSON我想要;
{
"DataItems" : [ {
"uuid" : "MFMS1-MC5",
"componentId" : "path1",
"eventType" : "Samples",
"type" : "PathFeedrate",
"dataItemId" : "pf",
"timestamp" : "2019-03-01T21:48:27.940558Z",
"sequence" : "68104",
"value" : "425.5333",
"name" : "Fact",
"subType" : "ACTUAL"
}, {
"uuid" : "MFMS1-MC5",
"componentId" : "path1",
"eventType" : "Samples",
"type" : "PathFeedrate",
"dataItemId" : "pf",
"timestamp" : "2019-03-01T21:48:30.244219Z",
"sequence" : "68117",
"value" : "0",
"name" : "Fact",
"subType" : "ACTUAL"
}, {
"uuid" : "MFMS1-MC5",
"componentId" : "path1",
"eventType" : "Events",
"type" : "SequenceNumber",
"dataItemId" : "seq",
"timestamp" : "2019-03-01T21:48:27.940558Z",
"sequence" : "68105",
"value" : "0",
"name" : "sequenceNum"
}, {
"uuid" : "MFMS1-MC5",
"componentId" : "path1",
"eventType" : "Events",
"type" : "Unit",
"dataItemId" : "unit",
"timestamp" : "2019-03-01T21:48:27.940558Z",
"sequence" : "68106",
"value" : "13",
"name" : "unitNum"
} ]
}
我的震动规范;
[
{
"operation": "shift",
"spec": {
"Samples": {
"*": {
"*": {
"@(3,uuid)": "Items.&2[#2].uuid",
"@(3,componentId)": "Items.&2[#2].componentId",
"$2": "Items.&2[#2].eventType",
"$1": "Items.&2[#2].type",
"*": "Items.&2[#2].&"
}
}
},
"Events": {
"*": {
"*": {
"@(3,uuid)": "Items.&2[#2].uuid",
"@(3,componentId)": "Items.&2[#2].componentId",
"$2": "Items.&2[#2].eventType",
"$1": "Items.&2[#2].type",
"*": "Items.&2[#2].&"
}
}
},
"Condition": {
"*": {
"*": {
"@(3,uuid)": "Items.&2[#2].uuid",
"@(3,componentId)": "Items.&2[#2].componentId",
"$2": "Items.&2[#2].eventType",
"$1": "Items.&2[#2].value",
"*": "Items.&2[#2].&"
}
}
}
}
},
{
"operation": "shift",
"spec": {
"Items": {
"*": {
"*": "DataItems[]"
}
}
}
}
]
此规范正常工作。因为我已经尝试了震动变换演示。
我正在使用 JSONTREEREDER 用于阅读 jolttransformrecord 的JSON。这是我的输入模式;
{
"name": "Items",
"namespace": "Items",
"type": "record",
"fields": [
{
"name": "uuid",
"type": "string"
},
{
"name": "componentId",
"type": "string"
},
{
"name": "Samples",
"type": ["null", {
"type": "map",
"values": {
"type": "array",
"items": {
"name": "SamplesDataItem",
"type": "record",
"fields": [
{
"name": "dataItemId",
"type": "string"
},
{
"name": "timestamp",
"type": "string"
},
{
"name": "sequence",
"type": "string"
},
{
"name": "value",
"type": "string"
},
{
"name": "name",
"type": ["null", "string"]
},
{
"name": "subType",
"type": ["null", "string"]
},
{
"name": "sampleRate",
"type": ["null", "string"]
},
{
"name": "statistic",
"type": ["null", "string"]
},
{
"name": "duration",
"type": ["null", "string"]
},
{
"name": "sampleCount",
"type": ["null", "string"]
},
{
"name": "compositionId",
"type": ["null", "string"]
},
{
"name": "resetTriggered",
"type": ["null", "string"]
}
]
}
}
}]
},
{
"name": "Events",
"type": ["null", {
"type": "map",
"values": {
"type": "array",
"items": {
"name": "EventsDataItem",
"type": "record",
"fields": [
{
"name": "dataItemId",
"type": "string"
},
{
"name": "timestamp",
"type": "string"
},
{
"name": "sequence",
"type": "string"
},
{
"name": "value",
"type": "string"
},
{
"name": "name",
"type": ["null", "string"]
},
{
"name": "subType",
"type": ["null", "string"]
},
{
"name": "compositionId",
"type": ["null", "string"]
},
{
"name": "resetTriggered",
"type": ["null", "string"]
}
]
}
}
}]
},
{
"name": "Condition",
"type": ["null", {
"type": "map",
"values": {
"type": "array",
"items": {
"name": "ConditionDataItem",
"type": "record",
"fields": [
{
"name": "dataItemId",
"type": "string"
},
{
"name": "timestamp",
"type": "string"
},
{
"name": "type",
"type": "string"
},
{
"name": "sequence",
"type": "string"
},
{
"name": "name",
"type": ["null", "string"]
},
{
"name": "subType",
"type": ["null", "string"]
},
{
"name": "nativeCode",
"type": ["null", "string"]
},
{
"name": "nativeSeverity",
"type": ["null", "string"]
},
{
"name": "qualifier",
"type": ["null", "string"]
},
{
"name": "statistic",
"type": ["null", "string"]
},
{
"name": "compositionId",
"type": ["null", "string"]
}
]
}
}
}]
}
]
}
我正在使用 JSONRECORDSETWRITER 用于写入转换的结果 JolttransFormRecord 。这是我的输出模式;
{
"name": "Items",
"type": "record",
"namespace": "Items",
"fields": [
{
"name": "DataItems",
"type": {
"type": "array",
"items": {
"name": "DataItems",
"type": "record",
"fields": [
{
"name": "uuid",
"type": "string"
},
{
"name": "componentId",
"type": "string"
},
{
"name": "eventType",
"type": "string"
},
{
"name": "type",
"type": "string"
},
{
"name": "dataItemId",
"type": "string"
},
{
"name": "timestamp",
"type": "string"
},
{
"name": "value",
"type": "string"
},
{
"name": "name",
"type": ["null", "string"],
"default": null
},
{
"name": "subType",
"type": ["null", "string"],
"default": null
}
]
}
}
}
]
}
这确实是记录处理实用程序中的错误，我已经编写了Nifi-6105来涵盖修复程序。好接收！
作为解决方法，由于您将JSON作为输入和输出，因此可以使用Jolttransformjson而不是JoltTransFormRecord。另外，如果您知道地图中的键（例如PathFeedrate，例如），则可以更改架构以将其视为记录而不是地图，这可能会使您绕过错误。