How to change the posted values with a spring mvc interceptor -

does know how change posted values spring mvc interceptor ? have seen examples none subject. know how them don't know how modify them.

@component public class cultureinterceptor implements handlerinterceptor {      @override     public void aftercompletion(httpservletrequest arg0, httpservletresponse arg1, object arg2, exception arg3)             throws exception {      }      @override     public void posthandle(httpservletrequest arg0, httpservletresponse arg1, object arg2, modelandview arg3)             throws exception {      }      @override     public boolean prehandle(httpservletrequest request, httpservletresponse response, object arg2) throws exception {         // posted values         string culture = request.getparameter("culture");         string = request.getparameter("a");         string b = request.getparameter("b");         system.out.println(string.format("[cultureinterceptor culture=%s, a=%s, b=%s]", culture, a, b));         if (culture != null && != null && b != null && "fr-fr".equals(culture)) {             = a.replace(",", ".");             b = b.replace(",", ".");         }         system.out.println(string.format("[cultureinterceptor culture=%s, a=%s, b=%s]", culture, a, b));         return true;     } 

above, have created copy of posted values [a] , [b] haven't modified them in request. idea ?

i answer own question. in fact rather complex , took me time find working solution. first, created filter in spring configuration class (spring boot environment exactly) :

@configuration @componentscan({ "istia.st.springmvc.config", "istia.st.springmvc.controllers", "istia.st.springmvc.models" }) @enableautoconfiguration public class config extends webmvcconfigureradapter {     @bean     public filter culturefilter() {         return new culturefilter();     }  } 

here declare filter (by default) filter every request before attains final handler. created filter :

public class culturefilter extends onceperrequestfilter {      @override     protected void dofilterinternal(httpservletrequest request, httpservletresponse response, filterchain filterchain)             throws servletexception, ioexception {         // next handler          filterchain.dofilter(new culturerequestwrapper(request), response);     } } 

[onceperrequestfilter] spring class. trick replace actual request new 1 [culturerequestwrapper(request)]. created culturerequestwrapper :

public class culturerequestwrapper extends httpservletrequestwrapper {      public culturerequestwrapper(httpservletrequest request) {         super(request);     }      @override     public string[] getparametervalues(string name) {         // posted values et b         if (name != null && (name.equals("a") || name.equals("b"))) {             string[] values = super.getparametervalues(name);             string[] newvalues = values.clone();             newvalues[0] = newvalues[0].replace(",", ".");             return newvalues;         }         // other cases         return super.getparametervalues(name);     }  } 

i redefined [getparametervalues] of [httpservletrequest] depends on final servlet manage request. have redefine [httpservletrequest] methods used servlet.