如何使用ScriptEngine从Java进行Ajax调用来调用javascript函数？

Question

I am getting following exception: jdk.nashorn.internal.runtime.ECMAException: ReferenceError: "$" is not defined

But how can I have jquery available for the javascript function?

Following is my code: Java code:

@RequestMapping(value={"/callAjax"}, method={RequestMethod.POST, RequestMethod.GET})
    public String callAjax(HttpServletRequest request, HttpServletResponse response, Model model) throws Exception {
        logger.info("request came to /callAjax");

        ScriptEngineManager manager = new ScriptEngineManager();
        ScriptEngine engine = manager.getEngineByName("JavaScript");
        InputStream fis = AjaxRequestController.class.getResourceAsStream("path to my js file");
        InputStreamReader fileReader = new InputStreamReader(fis);
        engine.eval(fileReader);
        Invocable inv = (Invocable) engine;
        inv.invokeFunction("ajaxMethod");
        return null;
    }

Javascript:

function ajaxMethod(){
    $.ajax({ 
        dataType: "json",
           type: "GET", 
           cache: false,
           url: 'myurl',
           success: function (data) {
            console.log(data);
        }
    });
}

Answer 1

In short, you can't!

Although nashorn (java 8's javascript engine) runs ECMAscript compliant javascript, but implicit objects from browsers like window , document are still not available. JQuery or $ , attaches it to window object hence it will not work. Use other ways for making async http requests in java.