How to use external javascript functions in java class

Question

I have javascript file (jalali.js) which it have a lot of functions. I want to call one of this functions in my java web application project (I mean somefile.Class file)

I had some research and i found these two methods:

    ScriptEngineManager factory = new ScriptEngineManager();
    ScriptEngine engine = factory.getEngineByName("JavaScript");
    engine.eval("print('Hello, World')");

But I can not understand how to call my js file (jalali.js) and how should i call my function

I will put function detail code here (from jalali.js)

    JalaliDate.gregorianToJalali = function(g_y, g_m, g_d)
    {
      g_y = parseInt(g_y);
      g_m = parseInt(g_m);
      g_d = parseInt(g_d);
      var gy = g_y-1600;
      var gm = g_m-1;
      var gd = g_d-1;
           ...
           ...

       return [jy, jm, jd];
    }

I want to use that function in my java application (MyClass.class)

public class TaskListModel extends BaseModel{
    private Date gDate;
    private String jalaliDate;


    public void setGDate(Date gDate) {
        this.gDate= gDate;
        this.jalaliDate =     Here i need call the js function ;
}

Answer 1

Well if this is the Rhino engine from 1.6 Java, then you can evaluate the code in jalali.js line by line - keeping the instance of engine alive through the runtime of the file. Also you can then execute the function like this: engine.eval("myfunction(arg1, arg2);");

I am not sure what you are trying to achieve

Step1. Read a line of the jalali.js file

Step2. engine.eval() the line

Step3. check if EOF - if yes, go to Step4 else go to Step1

Step4. engine.eval("your_function(arg1, arg2);");