通过将嵌套对象添加到Apache Nifi中的单列来将嵌套JSON转换为CSV

Question

我有一个嵌套的对象 JSON 结构，如下所示;

{
"Bikes":[
{
"Name":"KTM",
"Model":"2017",
"Colour":"Yellow"
}
{
"Name":"Yamaha",
"Model":"2020",
"Colour":"Black"
}
],
"Cars":[
{
"Name":"BMW",
"Model":"2017",
"Colour":"Yellow"
}
{
"Name":"Audi",
"Model":"2020",
"Colour":"Black"
}
]

我的输出CSV应该是这样的；

Bikes (Column 1)
{
"Name":"KTM",
"Model":"2017",
"Colour":"Yellow"
}
{
"Name":"Yamaha",
"Model":"2020",
"Colour":"Black"
}
Cars (Columns 2)
{
"Name":"BMW",
"Model":"2017",
"Colour":"Yellow"
}
{
"Name":"Audi",
"Model":"2020",
"Colour":"Black"
}
'''
I need to store the entire object Bikes in a single columns and likewise Cars in a single column

I am currently using a convert record processor to convert from JSON to CSV, MY avro schema for both JSON and CSV looks like this

｛“name”：“Sydney”，“type”：“record”，“namespace”：”Sydney“，“fields”：[｛“name:”Bikes“，“type:”｛“type:“array”，“items”：｛“name”：“Vehicle”，“type”：“record”，“field”：[{“name“：”name“，”type:“string”}，｛“name=”：“Model”，”type“：”string“}，{“name：”Colour“，”type“：”字符串“}}}｝，｛“name”：“Cars”，“type”：｛“type“：”array“，”items“：｛”name“：”Vehicle“，”type““：”record“，”fields“：[｛”名称“：”name“，”类型“：”string“｝，｛”name:“Model”，“type”：“string”｝，｝“name“：“Colour”，”type:“string“}]｝｝]｝

but in the convert record processor I am getting this error

[id=4d909c18-0177-1000-c1c1cd-9456a1775358]处理标准文件记录失败[uuid=63d04fc1-7edd-405b-8a9d-000bcdaa3d6c，索赔=标准内容索赔[resourceClaim=标准资源索赔[id=1611930760172-32，容器=默认，部分=32]，偏移=744686，长度=4]，偏移=0，名称=test.json，大小=4]；将路由到失败：从Convert记录[id=4d909c18-0177-1000-c1cd-9456a1775358]抛出的IOExc的：org.codehaus.jackson.JsonParseExc的：意外的字符（'T'（代码84））：预期一个有效的值（数字，字符串，数组，对象，'true'，'false'或'null'）在[Source：org.apache.nifi.stream.io.NonCloseableInputStream@5b8393b6； line： 1，列： 2]

Could anyone help me out on this?

Answer 1

您可能需要使用jolt变换来实现这一点，它有自己的处理器。像这样重构一个简单的嵌套JSON是他们记录的例子之一。