Groovy String to CSV - groovy

Question

I have a string input of the structure like:
[{name=John, dob=1970-07-27 00:00:00.0, score=81},
{name=Jane, dob=1970-07-28 00:00:00.0, score=77}]
I am trying to convert it to a CSV output. So expected output:
"name", "dob", "score"
"John", "1970-07-27 00:00:00.0", 81
"Jane", "1970-07-28 00:00:00.0", 77
So far I have tried something like
def js = "[{name=John, dob=1970-07-27 00:00:00.0, score=81}, {name=Jane, dob=1970-07-28 00:00:00.0, score=77}]"
def js = new JsonSlurper().parseText(s)
def columns = js*.keySet().flatten().unique()
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' )
This fails with groovy.json.JsonException: expecting '}' or ',' but got current char 'n'
Defining var js without quotes fails with expecting '}', found ','
Thanks in advance

Answer 1

I wrote this simple parser which will go splitting lines. If your input changes (i.e., comma or = is used in any other place), you will need a more complex parser:
input = '''[{name=John, dob=1970-07-27 00:00:00.0, score=81},
{name=Jane, dob=1970-07-28 00:00:00.0, score=77},
{name=Test, dob=1980-01-01 00:00:00.0, score=90}]'''
maps = (input =~ /\{(.*)\}/)
.collect {
it[1]
.split(', ')
.collectEntries { entry ->
entry.split '=' with {
[it.first(), it.last()]
}
}
}
assert maps == [
[name:'John', dob:'1970-07-27 00:00:00.0', score:'81'],
[name:'Jane', dob:'1970-07-28 00:00:00.0', score:'77'],
[name:'Test', dob:'1980-01-01 00:00:00.0', score:'90']
]

Answer 2

You can try this code snippet
import groovy.json.JsonSlurper
def s = '[{"name":"John", "dob":"1970-07-27 00:00:00.0", "score":81},{"name":"Jane", "dob":"1970-07-28 00:00:00.0", "score":77}]'
def js = new JsonSlurper().parseText(s)
def columns = js*.keySet().flatten().unique()
def encode = { e -> e == null ? '' : e instanceof String ? /"$e"/ : "$e" }
println columns.collect { c -> encode(c) }.join(',')
js.each {
println it.values().join(",")
} ​
I used Groovy JsonSlurper to convert String to Map, For this you need to give proper json String.