A Java class to execute the requirejs r.js optimizer with Rhino embedded (vs having to do this from the command line)

RequireJSOptimizer.java

import org.mozilla.javascript.Context;
import org.mozilla.javascript.Scriptable;
import org.mozilla.javascript.tools.shell.Global;

import java.io.File;
import java.io.FileInputStream;
import java.io.InputStreamReader;

class RequireJSOptimizer {
   
    public void optimize(String pathToRJs, String pathToBuildConfigJs) {
 
        try {
            System.out.println("Running r.js optimizer");
 
            // setup Rhino to call r.js
            Context cx = Context.enter();
            cx.setOptimizationLevel(9);
            Global global = new Global();
            global.init(cx);
            Scriptable scope = cx.initStandardObjects(global);
 
            // prepare arguments
            StringBuffer defineArguments = new StringBuffer("arguments= [");
            defineArguments.append("'-o', ");
            defineArguments.append("'"+pathToBuildConfigJs+"'");
            defineArguments.append("]");
            cx.evaluateString(scope, defineArguments.toString(), null, 1, null);
 
            // load r.js
            File rjs = new File(pathToRJs);
 
            // execute r.js with specified args
            cx.evaluateReader(scope, new InputStreamReader(new FileInputStream(rjs)), rjs.getName(), 1, null);
 
            System.out.println("Ran r.js optimizer");
 
        } catch (Exception e) {
            System.out.println("Failed to run r.js optimizer");
            e.printStackTrace(System.out);
        }
    }
}