Question

Is it possible to define things externally into Properties files for our annotations on Spring Controllers?

Suppose I have the following Controller

@Controller
@RequestMapping(value = "processModel.jsp")
public class ProcessorController {

    @RequestMapping(method = RequestMethod.GET)
    public String displayModel() {
         //Code to load processor
         return "processModel";
    }

    @RequestMapping(method = RequestMethod.POST, params="submit=Refresh")
    public String refreshModel() {
         //Code to refresh data
         return "processModel";
    }

    @RequestMapping(method = RequestMethod.POST, params="submit=Save Model")
    public String saveModel() {
        //Code to save model
        return "processModel";
    }
}

Assume the following HTML is generated:

<input type="submit" name="submit" value="Save Model" />
<input type="submit" name="submit" value="Refresh" />

It’d be nice to have these params externalized so that we only have to define them once in a properties file. That way if we need to change the label on a submit button in the JSP, we only need to change it in the properties file, rather than in two places.

Is this possible?

Answer 1

Annotation parameter values need to be a literal or refer to a constant field, so the externalized dynamic value cannot be injected into the @RequestMapping annotation. An alternative may be to drive the behavior using some other hidden form variable mapped to a literal(SAVEMODEL/REFRESH) instead of the text that is displayed to the user(you may get a requirement to internationalize the text displayed to the user at some point and this model will break then)