Nashorn Javascript CLI that will report the download size of a given URL as a command line parameter

downloadsize.js

#!env jjs
// jjs filesize.js -- config.txt
// Sample config.txt:
//    http://unec.edu.az/application/uploads/2014/12/pdf-sample.pdf

var Files = Java.type('java.nio.file.Files');
var Paths = Java.type('java.nio.file.Paths');
var URL = Java.type('java.net.URL');

function getSize(url) {
    var connection = new java.net.URL(url).openConnection();
    var len = connection.getHeaderField('Content-Length');    // Just the header, please
    connection.disconnect();
    return len;
}

var configFile = arguments[0];
var path = Paths.get(configFile);
var lines = Files.readAllLines(path);
var url = lines[0];
print(getSize(url), '-', url);