Remove hyphens from keys in deeply nested map - groovy

Question

I posted this question in the Groovy mailing lists, but I've not yet gotten an answer. I was wondering if someone can help here. I am re-posting relevant text from my original question.
I have an input json that’s nested, that is read via a JsonSlurper, and some of the keys have hyphens in them. I need to replace those keys that have hyphens with underscores and convert it back to json for downstream processing. I looked at the JsonGenerator.Options documentation and I could not find any documentation for this specific requirement.
I also looked through options to iterate through the Map that is produced from JsonSlurper, but unfortunately I’m not able to find an effective solution that iterates through a nested Map, changes the keys and produces another Map which could be converted to a Json string.
Example Code
import groovy.json.*
// This json can be nested many levels deep
def inputJson = """{
"database-servers": {
"dc-1": [
"server1",
"server2"
]
},
"discovery-servers": {
"dc-3": [
"discovery-server1",
"discovery-server2"
]
}
}
"""
I need to convert the above to json that looks like the example below. I can iterate through and convert using the collectEntries method which only works on the first level, but I need to do it recursively, since the input json can be an nested many levels deep.
{
"database_servers": {
"dc_1": [
"server1",
"server2"
]
},
"discovery_servers": {
"dc_3": [
"discovery-server1",
"discovery-server2"
]
}
}

Answer 1

Seems like you just need a recursive method to process the slurped Map and its sub-Maps.
import groovy.json.JsonSlurper
JsonSlurper slurper = new JsonSlurper()
def jsonmap = slurper.parseText( inputJson )
Map recurseMap( def inputMap ) {
return inputMap.collectEntries { key, val ->
String newkey = key.replace( "-", "_" )
if ( val instanceof Map ) {
return [ newkey, recurseMap( val ) ]
}
return [ newkey, val ]
}
}
def retmap = recurseMap( jsonmap )
println retmap // at this point you can use output this however you like