Flat an multiply arrays in Nifi - json

I have the following JSON input:
{
"id": 9256123,
"data": [
{
"id": 242424,
"attributes": [
{
"currency": "EUR",
"price": "99,99"
}
]
},
{
"id": 22222,
"attributes": [
{
"currency": "EUR",
"price": "299,99"
}
]
}
]
}
I need to remove/flat the array
The output I need:
{
"id": 9256123,
"data": [
{
"id": 242424,
"currency": "EUR",
"price": "99,99"
},
{
"id": 22222,
"currency": "EUR",
"price": "299,99"
}
]
}
How can I do this with the Jolt-Processor? Or maybe with the ReplaceText-Processor?

You can walk by the attributes array with a shift transformation within a JoltTransformJSON processor such as
[
{
"operation": "shift",
"spec": {
"*": "&",
"data": {
"*": {
"attributes": {
"*": {
"#": "&4[&3]", // go four level up the tree and grab "data", and walk by indexes of it to return array of objects resukt by using "[&3]"
"#(2,id)": "&4[&3].id"
}
}
}
}
}
}
]
the demo on the site http://jolt-demo.appspot.com/ is

Related

A JOLT transformation question about mapping reference

This is an input that needs to be transformed using Jolt Transformation to obtain the expected output.
I am attempting to create a jolt transformation for the below input:
{
"flights": [
{
"id": "123",
"route": "BJS-SIN"
},
{
"id": "456",
"route": "SIN-PEK"
},
{
"id": "789",
"route": "SIN-BJS"
}
],
"prices": [
{
"id": "abc",
"amount": 560
},
{
"id": "def",
"amount": 780
}
],
"solutions": [
{
"price-ref": "abc",
"flights-ref": [
"123",
"456"
]
},
{
"price-ref": "def",
"flights-ref": [
"123",
"789"
]
}
]
}
Desired output would like :
{
"solutions": [
{
"flights": [
{
"id": "123",
"route": "BJS-SIN"
},
{
"id": "456",
"route": "SIN-PEK"
}
],
"price": {
"id": "abc",
"amount": 560
}
},
{
"flights": [
{
"id": "123",
"route": "BJS-SIN"
},
{
"id": "789",
"route": "SIN-BJS"
}
],
"price": {
"id": "def",
"amount": 780
}
}
]
}
As the output, all the data should be constructed refer to the solutions node. How about the mapping expression in JOLT?
all the values from the source json are generated randomly and the keys names are fixed.
I had tried many times but could not find the right spec, so please help.
You can use this spec:
[
{
"operation": "shift",
"spec": {
"*": "&",
"flights|prices": {
"*": {
"*": "&2.#(1,id).&"
}
}
}
},
{
"operation": "shift",
"spec": {
"solutions": {
"*": {
"flights*": {
"*": {
"*": {
"#(6,flights.&)": "&5[&4].flights[&2]"
}
}
},
"price*": {
"*": {
"#(5,prices.&)": "&4[&3].price"
}
}
}
}
}
}
]

conversion array into array by jolt

I have following json data . I want to transform following data by jolt nifi processor into result data
{
"data": [
{
"source": "Environment Sensors",
"alert_count": "2",
"category": "envs",
"alert_array": {
"alerts": [
{
"name": "neeraj",
"id": "123"
},
{
"name": "arun",
"id": "897"
}
]
}
}
]
}
result data
{
"alert": "2",
"subcategory": "envs",
"alert_array": [
{
"category": "Environment Sensors",
"newName": "neeraj",
"newID": "123"
},
{
"category": "Environment Sensors",
"newName": "arun",
"newID": "897"
}
]
}
Here value of category is the value of source
You can use the following shift transformation spec
[
{
"operation": "shift",
"spec": {
"data": {
"*": {
"alert_count": "alert",
"category": "sub&",
"alert_array": {
"*": {
"*": {
"#(3,category)": "&3[&1].category",
"name": "&3[&1].newName",
"id": "&3[&1].newID"
}
}
}
}
}
}
}
]
first reach the elements of the innermost object, and determine the value of the category element by going 3 levels up along with the others which are alreay located there.

Create array of simpler JSON objects from a nested JSON using jolt

My input JSON is like
{
"common": {
"name": "abc"
},
"details": {
"id": 4,
"node": [
{
"name": "node1",
"array2": []
},
{
"name": "node2",
"array2": [
{
"name": "node2_a2_1"
}
]
},
{
"name": "node3",
"array2": [
{
"name": "node3_a2_1"
},
{
"name": "node3_a2_2"
},
{
"name": "node3_a2_3"
}
]
}
]
}
}
What I want is for each leaf node in array2 (e.g. {"name": "node3_a2_1"}) I will traverse towards the root and add all common items and create an array of JSON objects without any nested object. So, the output I want is like
[
{
"common_name": "abc",
"id": 4,
"node_name": "node2",
"name": "node2_a2_1"
},
{
"common_name": "abc",
"id": 4,
"node_name": "node3",
"name": "node3_a2_1"
},
{
"common_name": "abc",
"id": 4,
"node_name": "node3",
"name": "node3_a2_2"
},
{
"common_name": "abc",
"id": 4,
"node_name": "node3",
"name": "node3_a2_3"
}
]
Could you please suggest how can I do that?
You can walk through the array2 while picking values of each element from their original location in the JSON value.
For example; traverse } four times to grab the value of id by using #(4,id), and use #(3,name)[&1] as the common distinguishing identifier for each attribute such as
[
{
"operation": "shift",
"spec": {
"details": {
"node": {
"*": {
"array2": {
"*": {
"#(5,common.name)": "#(3,name)[&1].common_name",
"#(4,id)": "#(3,name)[&1].id",
"#(2,name)": "#(3,name)[&1].node_name",
"name": "#(3,name)[&1].&"
}
}
}
}
}
}
},
{
"operation": "shift",
"spec": {
"*": {
"*": ""
}
}
}
]

Applying cardinality for multiple columns in Jolt

I am trying to apply Jolt for below data
input:
[
{
"id": "500",
"code": "abc",
"date": "2020-10-10",
"category": 1,
"amount": 100,
"result": 0
},
{
"id": "500",
"code": "abc",
"date": "2020-10-10",
"category": 2,
"amount": 200,
"result": 1
}
]
jolt used:
[
{
"operation": "shift",
"spec": {
"*": {
"id": "#(1,id).id",
"code": "#(1,id).code",
"date": "#(1,id).group1.date",
"category": "#(1,id).group1.group2[&1].category"
}
}
},
{
"operation": "cardinality",
"spec": {
"*": {
"id": "ONE"
}
}
},
{
"operation": "shift",
"spec": {
"*": ""
}
}
]
current output:
{
"id": "500",
"code": [
"abc",
"abc"
],
"group1": {
"date": [
"2020-10-10",
"2020-10-10"
],
"group2": [
{
"category": 1
},
{
"category": 2
}
]
}
}
expected:
{
"id": "500",
"code": "abc",
"group1": {
"date": "2020-10-10",
"group2": [
{
"category": 1
},
{
"category": 2
}
]
}
}
If i keep column of code & date in cardinality, it's fine. But in my use case, there are multiple such columns to be added. Are there any better ways to handle this scenario?
You should add each added node and use "*" wildcard to represent the rest of the attributes within the cardinality transformation such as
{
"operation": "cardinality",
"spec": {
"*": {
"*": "ONE",
"group1": {
"*": "ONE",
"group2": "MANY"
}
}
}
}
where "group2": "MANY" will make group2 to be excepted for extracting only the first element of the respective list.
the demo on the site http://jolt-demo.appspot.com/ :

JOLT transform flatten nested array with key value pairs

I'm trying to transform the following JSON
{
"data": {
"keyvalues": [
{
"key": "location",
"value": "sydney, au"
},
{
"key": "weather",
"value": "sunny"
}
]
},
"food": {
"name": "AllFoods",
"date": "2018-03-08T09:35:17-03:00",
"count": 2,
"food": [
{
"name": "chocolate",
"date": "2018-03-08T12:59:58-03:00",
"rating": "10",
"data": null
},
{
"name": "hot dog",
"date": "2018-03-08T09:35:17-03:00",
"rating": "7",
"data": {
"keyvalues": [
{
"key": "topping",
"value": "mustard"
},
{
"key": "BUN type",
"value": "toasted"
},
{
"key": "servings",
"value": "2"
}
]
}
}
]
}
}
Into, something simpler like this, using JOLT (in NIFI). Bringing the first top-level food attributes (name, date, count) into the header and then pulling the nested food array up, and then flattening out the food.data.keyvalues into a dict/hashmap.
{
"header": {
"location": "sydney, au",
"weather": "sunny",
"date": "2018-03-08",
"count": 2
},
"foods": [
{
"name": "chocolate",
"date": "2018-03-08T12:59:58-03:00",
"rating": "10"
},
{
"name": "hot dog",
"date": "2018-03-08T09:35:17-03:00",
"rating": "7",
"topping": "mustard",
"bun_type": "toasted",
"servings": "2"
}
]
}
I've got the first data part working, but I'm not sure how to handle the nested food element. The top level food info needs to move into the header section, and the second level food array, needs to flatten out the data.keyvalues.
Current spec... (only handles the top data.keyvalues)
[
{
"operation": "shift",
"spec": {
"data": {
"keyvalues": {
"*": { "#value": "#key" }
}
}
}
}
]
Spec
[
{
"operation": "shift",
"spec": {
"data": {
"keyvalues": {
"*": {
"value": "header.#(1,key)"
}
}
},
"food": {
"date": "header.date",
"count": "header.count",
"food": {
"*": {
"name": "foods[&1].name",
"date": "foods[&1].date",
"rating": "foods[&1].rating",
"data": {
"keyvalues": {
"*": {
"value": "foods[&4].#(1,key)"
}
}
}
}
}
}
}
}
]