RIT

import java.io.BufferedReader;
import java.io.File;
import java.io.FileReader;
import java.io.IOException;

import javax.script.ScriptEngine;
import javax.script.ScriptEngineManager;
import javax.script.ScriptException;


public class Main {

    public static void main (String [] args)
    {
        String variableWhile="";

        File f = new File("c:/scriptJava.java");
        if (f.exists())
            System.out.println("Archivo disponible.");

        try {
            String archivoJs = "";
            FileReader fr = new FileReader("c:/scriptJava.java");
            BufferedReader br = new BufferedReader(fr);
            while ((variableWhile=br.readLine()) != null)
            {
                archivoJs += variableWhile;
                System.out.println("Leido: " + archivoJs);
            }

            ScriptEngineManager sem = new ScriptEngineManager();
            ScriptEngine script = sem.getEngineByName("script");
            script.eval("System.out.println(\"HOLA\");");
        } catch (IOException | ScriptException e) { e.printStackTrace(); }

    }

}