scala - How to parse JSON string into separate records? - json

Question

I wrote a method to concatenate JSON values.
def mergeSales(storeJValue: JValue): String = {
val salesJValue: JValue = parse(rawJson)
val store = compact(render(storeJValue))
val sales = compact(render(salesJValue))
val mergedSales: String = s"""{"store":$store,"sales":$sales}"""
mergedSales
}
As a result I'm getting strings like this, a store with an array of corresponding sales:
{"store":{"store_id":"01","name":"Store_1"}, "sales":[{"saleId": 10, "name": "New name1", "saleType": "New Type1"}, {"saleId": 20, "name": "Some name1", "saleType": "SomeType5"}, {"saleId": 30, "name": "Some name3", "saleType": "SomeType3"}]}
How should I parse it to get a list of records where the same store is mapped to each sale from the array? I want it to look like this:
{"store":{"store_id":"01","name":"Store_1"}, "sale":{"saleId": 10, "name": "New name1", "saleType": "New Type1"}}
{"store":{"store_id":"01","name":"Store_1"}, "sale":{"saleId": 20, "name": "New name2", "saleType": "New Type2"}}
{"store":{"store_id":"01","name":"Store_1"}, "sale":{"saleId": 30, "name": "Some name3", "saleType": "SomeType3"}}
Sales have a huge amount of fields in reality, so creating a case class will be rather complex.

Answer 1

i think best way to use json4s API which will extract all your json code and convert it into map than you can easily traverse
you required to create case class :
case class Store(store_id: String, name: String)
case class Sale(saleId:String, name:String, saleType:String)
case class Result(store: Store, sale: Sale)
case class SaleStore(store: Store, sales: List[Sale])
then it is very straight forward to get solution using json4s
val str =
"""{
| "store": {
| "store_id": "01",
| "name": "Store_1"
| },
| "sales": [
| {
| "saleId": 10,
| "name": "New name1",
| "saleType": "New Type1"
| },
| {
| "saleId": 20,
| "name": "Some name1",
| "saleType": "SomeType5"
| },
| {
| "saleId": 30,
| "name": "Some name3",
| "saleType": "SomeType3"
| }
| ]
|}""".stripMargin
import org.json4s._
import org.json4s.jackson.JsonMethods._
implicit val formats = org.json4s.DefaultFormats
val saleStore = parse(str).extract[SaleStore]
val result = saleStore.sales.flatMap(sale => List(saleStore.store -> sale))
val mapper: ObjectMapper = new ObjectMapper()
mapper.registerModule(DefaultScalaModule)
result.map(r => mapper.writeValueAsString(Result(r._1, r._2))).foreach(println)
output:
{"store":{"store_id":"01","name":"Store_1"},"sale":{"saleId":"10","name":"New name1","saleType":"New Type1"}}
{"store":{"store_id":"01","name":"Store_1"},"sale":{"saleId":"20","name":"Some name1","saleType":"SomeType5"}}
{"store":{"store_id":"01","name":"Store_1"},"sale":{"saleId":"30","name":"Some name3","saleType":"SomeType3"}}