org.springframework.web.bind.support
Interface WebArgumentResolver

public interface WebArgumentResolver

SPI for resolving custom arguments for a specific handler method parameter. Typically implemented to detect sppecial parameter types, resolving well-known argument values for them.

A typical implementation could look like as follows:

 public class MySpecialArgumentResolver implements ArgumentResolver {

   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:

AnnotationMethodHandlerAdapter.setCustomArgumentResolvers(org.springframework.web.bind.support.WebArgumentResolver[]), AnnotationMethodHandlerAdapter.setCustomArgumentResolvers(org.springframework.web.bind.support.WebArgumentResolver[])

Field Summary

static Object

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

Method Summary

Object

resolveArgument(MethodParameter methodParameter, NativeWebRequest webRequest) Resolve an argument for the given handler method parameter within the given web request.

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

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