Java, nashorn accessing another js file

Question

Is it possible to include one js from another with java nashorn engine?

ScriptEngine engine = new ScriptEngineManager().getEngineByName("Nashorn");
InputStreamReader rs = new InputStreamReader(new FileInputStream(new File(.../script.js));
engine.eval(rs);

script.js

var System = Java.type('java.lang.System');
// document.write("./test.js"); - javax.script.ScriptException: ReferenceError: "document" is not defined 
// require('./test.js'); - require is not defined

test.js

System.out.println("reading test.js file");

i want to create top level script (in this example its script.js) and use it as a library for other scripts in same directory.

Your ScriptEngine should be obtained by the name of "nashorn" and not "Nashorn" — Krishna Prashatt, May 30 '18 at 13:21

score 24 · Accepted Answer · answered Mar 14 '15 at 23:59

you can use Nashorn's load() function

https://wiki.openjdk.java.net/display/Nashorn/Nashorn+extensions

// can load script from files, URLs

load("foo.js"); // loads script from file "foo.js" from current directory
load("http://www.example.com/t.js"); // loads script file from given URL

// loads script from an object's properties. 

// Object should have "script" and "name" properties.
//     "script" property contains string code of the script. 
//     "name" property specifies name to be used while reporting errors from script
// This is almost like the standard "eval" except that it associates a name with
// the script string for debugging purpose.

load({ script: "print('hello')", name: "myscript.js"})

// load can also load from pseudo URLs like "nashorn:", "fx:". "nashorn:" pseudo URL scheme
// for nashorn's built-in scripts. "fx:" pseudo URL scheme for JavaFX support scripts

// load nashorn's parser support script - defines 'parse'
// function in global scope

load("nashorn:parser.js"); 

// load Mozilla compatibility script - which defines global functions
// like importPackage, importClass for rhino compatibility.

load("nashorn:mozilla_compat.js");

score 1 · Answer 2 · answered Feb 28 '17 at 15:27

Nashorn is brilliant.

And it comes with the built-in load method !!!

load can take a URL so you can exploit great JavaScript libraries on the CDNJS

if you use nudge4j you can get kangax's html minifier running just like this:

load('https://cdnjs.cloudflare.com/ajax/libs/html-minifier/3.3.3/htmlminifier.js')
minify = require('html-minifier').minify;
input = '<div> <p>    foo </p>    </div>';
output = minify(input, { collapseWhitespace: true });

Java, nashorn accessing another js file

2 Answers2