use strict;
use warnings;
use JSON;
use XML::Simple;
use Data::Rmap qw(rmap_ref);
use Data::Dumper;

my $text = '{"a":"x","b":true}';
my $result = decode_json($text);
print Dumper($result);
rmap_ref { $_ = "$_" if JSON::is_bool($_) } $result; # or numify, like ikegami shows above
print Dumper($result);
my $rec = XMLout( $result, RootName => 'root', SuppressEmpty => 1);
print Dumper($rec);