code: private void initEngine() {
      engine = (NashornScriptEngine) new ScriptEngineManager().getEngineByName("nashorn");
  
      try {
        engine.eval("(function(global){global.global = global})(this);");
        engine.eval(NashornVueTemplateCompiler.NASHORN_VUE_TEMPLATE_COMPILER);
      } catch (ScriptException e) {
        e.printStackTrace();
      }
    }
docs: Init the Nashorn engine and load the Vue compiler in it.