Mapping HTTP request value to object in Sprint Boot application when field and value has different field name? - spring-boot

Question

This instance of class AuthorizationRequest is created during HTTP request, params are sent in query string.
#RequestMapping(value = "/authorize", method = {RequestMethod.GET, RequestMethod.POST})
public String authorize(
#Valid AuthorizationRequest authorizationRequest,
BindingResult result
) {
I would like to use this code, this is an example parameter from AuthorizationRequest class:
#NotEmpty
#JsonProperty("client_id")
private String clientId;
but new instance has a filed clientId empty, because in query string there is a value for this parameter under client_id parameter.
Is there some way how to tell Spring which parameter from HTTP request should use for one particular field of created instance? I need to solve problem with different naming clientId andclient_id`.

Answer 1

What you need is a setter to handle each kind of clientId. Keep in mind that if both clientId and client_id is specified that it is unknown which will take precedence.
//These methods will allow clientId or client_id
to be used as arguments setting the same field this.clientId
public void setClient_id(String client_id) {
this.clientId = client_id;
}
public void setClientId(String client_id) {
this.clientId = client_id;
}
I tested this with a post and a get
get - http://localhost:8080/authorize?clientId=2&username=someusername
get - http://localhost:8080/authorize?client_id=2&username=someusername
post - http://localhost:8080/authorize
Content-Type: application/x-www-form-urlencoded
Body: clientId=2&username=someusername
or Body: client_id=2&username=someusername
I was only able to have #JsonProperty("client_id") to be recognized when I annotated AuthorizationRequest with #RequestBody and then used application/json instead of application/x-www-form-urlencoded

Answer 2

I found the solution with own implementation of org.springframework.web.method.supportHandlerMethodArgumentResolver.
Resolver implementation:
public class AuthorizationRequestResolver implements HandlerMethodArgumentResolver {
private static Logger LOG = Logger.getLogger(AuthorizationRequestResolver.class);
#Override
public boolean supportsParameter(MethodParameter parameter) {
return parameter.getParameterType().equals(AuthorizationRequest.class);
}
#Override
public Object resolveArgument(MethodParameter parameter,
ModelAndViewContainer mavContainer,
NativeWebRequest webRequest,
WebDataBinderFactory binderFactory) throws Exception {
HttpServletRequest request = (HttpServletRequest) webRequest.getNativeRequest();
AuthorizationRequest authRequest = mapFromServletRequest(request);
return authRequest;
}
private AuthorizationRequest mapFromServletRequest(HttpServletRequest request) {
AuthorizationRequest authorizationRequest = new AuthorizationRequest();
authorizationRequest.setClientId(request.getParameter("client_id"));
authorizationRequest.setRedirectUri(request.getParameter("request_uri"));
authorizationRequest.setResponseType(request.getParameter("response_type"));
authorizationRequest.setScope(request.getParameter("scope"));
authorizationRequest.setState(request.getParameter("state"));
return authorizationRequest;
}
}
and cofiguration class:
#Configuration
public class WebappConfig extends WebMvcConfigurerAdapter {
#Override
public void addArgumentResolvers(List<HandlerMethodArgumentResolver> argumentResolvers) {
argumentResolvers.add(new AuthorizationRequestResolver());
}
}