Nifi, Json data - arrays

Question

I have JSON input data as
{
"type": "insert",
"timestamp": 1536959101000,
"binlog_filename": "mysql-bin-changelog.234234",
"binlog_position": 223,
"database": "test",
"table_name": "demo",
"table_id": 138,
"columns": [
{
"id": 1,
"name": "id",
"column_type": 12,
"value": "IboECKV "
},
{
"id": 2,
"name": "col2",
"column_type": 93,
"value": "Fri Sep 14 21:05:02 UTC 2018"
},
{
"id": 3,
"name": "col3",
"column_type": 4,
"value": 10
},
{
"id": 4,
"name": "col4",
"column_type": 4,
"value": 0
}
]
}
If column_type =93 (datetime): convert value to : yyyy-MM-dd HH:mm:ss.SSSZ
So the the target out put is
[
{
"id": "IboECKV "
},
{
"col2": "2018-09-14 21:05:02.000Z"
},
{
"col3": 10
},
{
"col4": 0
}
]
Do you know how to solved that case?
Many thanks,

Answer 1

You can use ExecuteScript and leverage Groovy to do the parsing of Json input and the date and format it to however format you want using SimpleDateFormat.
A quick example:
import java.text.SimpleDateFormat
import java.util.Date
import groovy.json.JsonSlurper
import groovy.json.JsonOutput
import org.apache.commons.io.IOUtils
import java.nio.charset.StandardCharsets
flowFile = session.get()
if(!flowFile)return
def text = ''
session.read(flowFile, {inputStream ->
text = IOUtils.toString(inputStream, StandardCharsets.UTF_8)
} as InputStreamCallback)
def jsonSlurper = new JsonSlurper()
def object = jsonSlurper.parseText(text)
def columnsSize = object.columns.size
0.upto(columnsSize - 1) {
if (object.columns[it].column_type == 93 ) {
oldDate = object.columns[it].value
sdfmt2= new SimpleDateFormat('dd-M-yyyy')
parsedDate = sdfmt2.parse(oldDate)
object.columns[it].value = parsedDate
output = JsonOutput.toJson(object)
flowFile = session.write(flowFile, {outputStream ->
outputStream.write(output.getBytes(StandardCharsets.UTF_8))
} as OutputStreamCallback)
session.transfer(flowFile, REL_SUCCESS)
}
}