Groovy example of printing groovy header fields after openConnection() call

printHeaderFields.groovy

def NEW_LINE = System.getProperty("line.separator")
if (args.length < 1)
{
   println "Enter a URL as an argument."
   System.exit(-1)
}
def address = args[0]
def urlInfo = address.toURL()
println "===================================================================="
println "====== HEADER FIELDS FOR URL ${address}"
println "===================================================================="
def connection = urlInfo.openConnection()
headerFields = connection.getHeaderFields()
headerFields.each {println it}