How to modify request body before reaching controller in spring boot

Question

I have a spring boot application. I change the request body of every post request. Is it possible to modify the request body before the request reaches the controller. Please include an example.

Answer 1

Another alternative would be adding an attribute to the HttpServletRequest object. And after that you can read that attribute in the Controller class with @RequestAttribute annotation.

In the Interceptor

@Component
    public class SimpleInterceptor extends HandlerInterceptorAdapter {

        @Override
        public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
                throws ServletException, IOException {
            String parameter = request.getParameter("parameter");
            if (parameter == "somevalue") {
                request.setAttribute("customAttribute", "value");
            }

            return true;
        }

    }

In the Controller

@RestController
@RequestMapping("")
public class SampleController {


    @RequestMapping(value = "/sample",method = RequestMethod.POST)
    public String work(@RequestBody SampleRequest sampleRequest, @RequestAttribute("customAttribute") String customAttribute) {
        System.out.println(customAttribute);
        return "This works";
    }
}

This has advantage of not modifying the request body.