Groovy code to convert json to CSV file - groovy

Question

Does anyone have any sample Groovy code to convert a JSON document to CSV file? I have tried to search on Google but to no avail.
Example input (from comment):
[ company_id: '1',
web_address: 'vodafone.com/',
phone: '+44 11111',
fax: '',
email: '',
addresses: [
[ type: "office",
street_address: "Vodafone House, The Connection",
zip_code: "RG14 2FN",
geo: [ lat: 51.4145, lng: 1.318385 ] ]
],
number_of_employees: 91272,
naics: [
primary: [
"517210": "Wireless Telecommunications Carriers (except Satellite)" ],
secondary: [
"517110": "Wired Telecommunications Carriers",
"517919": "Internet Service Providers",
"518210": "Web Hosting"
]
]
More info from an edit:
def export(){
def exportCsv = [ [ id:'1', color:'red', planet:'mars', description:'Mars, the "red" planet'],
[ id:'2', color:'green', planet:'neptune', description:'Neptune, the "green" planet'],
[ id:'3', color:'blue', planet:'earth', description:'Earth, the "blue" planet'],
]
def out = new File('/home/mandeep/groovy/workspace/FirstGroovyProject/src/test.csv')
exportCsv.each {
def row = [it.id, it.color, it.planet,it.description]
out.append row.join(',')
out.append '\n'
}
return out
}

Answer 1

Ok, how's this:
import groovy.json.*
// Added extra fields and types for testing
def js = '''{"infile": [{"field1": 11,"field2": 12, "field3": 13},
{"field1": 21, "field4": "dave","field3": 23},
{"field1": 31,"field2": 32, "field3": 33}]}'''
def data = new JsonSlurper().parseText( js )
def columns = data.infile*.keySet().flatten().unique()
// Wrap strings in double quotes, and remove nulls
def encode = { e -> e == null ? '' : e instanceof String ? /"$e"/ : "$e" }
// Print all the column names
println columns.collect { c -> encode( c ) }.join( ',' )
// Then create all the rows
println data.infile.collect { row ->
// A row at a time
columns.collect { colName -> encode( row[ colName ] ) }.join( ',' )
}.join( '\n' )
That prints:
"field3","field2","field1","field4"
13,12,11,
23,,21,"dave"
33,32,31,
Which looks correct to me