Accessing java variable from javascript in spring mvc

Question

i am relatively new to spring mvc.what i am trying to do is pass a variable as model attribute and try and access it on page load with javascript on my JSP page. my java code is as follows

   model.addAttribute("leagueCode",leagueCode);
    model.addAttribute("league","new");
    return "redirect:/Dashboard";

and on jsp side i am trying to access it by following

<script type="text/javascript"> function myFunction() { var leagueCode=${leagueCode}; alert(leagueCode); } </script> </head> <body onload="myFunction()">

but i am getting the value as blank. is this the right way i am following or is there any other way this has to be done? please help

this way it's not possible. You need to bind the model value in DOM element with proper Id or class and get that value in script using that ID — Gaurav Sharma
– Gaurav Sharma, Commented Dec 3, 2017 at 5:47

Juan · Accepted Answer · 2017-12-04 13:28:33Z

1

In the JSP page you can set the values as javascript variables by adding a script tag in the <head> with the assignment inside as a json object for example:

<script>
var myServerSideVars = {
    "aServerSideVarName" : "<here you set the value with el/jslt/scriptlet>",
    "anotherServerSideVarName" : "<here you set the value with el/jslt/scriptlet>" 
};
</script>

EDIT I

Example using EL (Expression Language) but the same could be done with scriptlets if you are using that (<% %>):

Lets say in your Servlet you put a Car instance in the request before forwarding to the JSP page.

The car:

public class Car{
    protected String brand;
    protected String year;

    //getters and setters for the two properties.
}

In the Servlet you put it into the request:

Car car = new Car();
car.setBrand("BMW");
car.setYear("2017");
request.setAttribute("carInRequest", car);

In the JSP you set it to a Json Object accessible from javascript. Before closing the body tag I put a simple example of how the var can be accessed from javascript. I haven't run it so it may have some typo or error to correct:

<%@taglib prefix = "c" uri = "http://java.sun.com/jsp/jstl/core" %>

    <html>
       <head><title>System.out.println</title>
          <script>
              var aCar= {
                     "brand" : "${requestScope.carInRequest.brand}",
                     "year"  : "${requestScope.carInRequest.year}"
              };
          </script>
       </head>

       <body>
          <h2>Brand: <span id="brandPlaceHolder"></span></h2>
          <h2>Year: <span id="yearPlaceHolder"></span></h2>

       </body>
       <script>
           var brandSpan = document.findElementById("brandPlaceHolder");
           brandSpan.html = aCar.brand;
           var yearSpan = document.findElementById("yearPlaceHolder");
           brandSpan.html = aCar.year;
       </script>
    </html>

edited Dec 4, 2017 at 13:28

answered Dec 3, 2017 at 6:00

Juan

5,6112 gold badges17 silver badges27 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

ExTincT Over a year ago

sir can u please elaborate on this.i am having difficulties in understanding this

Juan Over a year ago

I have added a trivial example.

Collectives™ on Stack Overflow

Accessing java variable from javascript in spring mvc

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related