Package org.springframework.web.bind.support

Interface WebArgumentResolver

  • Functional Interface:
    This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.
    @FunctionalInterface
public interface WebArgumentResolver
    SPI for resolving custom arguments for a specific handler method parameter. Typically implemented to detect special parameter types, resolving well-known argument values for them.

    A typical implementation could look like as follows: 

     public class MySpecialArgumentResolver implements WebArgumentResolver {

   public Object resolveArgument(MethodParameter methodParameter, NativeWebRequest webRequest) {
     if (methodParameter.getParameterType().equals(MySpecialArg.class)) {
       return new MySpecialArg("myValue");
     }
     return UNRESOLVED;
   }
 }
    Since:
    2.5.2
    Author:
    Juergen Hoeller
    See Also:
    RequestMappingHandlerAdapter.setCustomArgumentResolvers(java.util.List<org.springframework.web.method.support.HandlerMethodArgumentResolver>)

    • Field Detail

      • UNRESOLVED

        static final Object UNRESOLVED
        Marker to be returned when the resolver does not know how to handle the given method parameter.

    • Method Detail

      • resolveArgument

        @Nullable
Object resolveArgument​(MethodParameter methodParameter,
                       NativeWebRequest webRequest)
                throws Exception
        Resolve an argument for the given handler method parameter within the given web request.
        Parameters:
        methodParameter - the handler method parameter to resolve
        webRequest - the current web request, allowing access to the native request as well
        Returns:
        the argument value, or UNRESOLVED if not resolvable
        Throws:
        Exception - in case of resolution failure