Package org.springframework.web.method.annotation

Class AbstractWebArgumentResolverAdapter

java.lang.Object

org.springframework.web.method.annotation.AbstractWebArgumentResolverAdapter

All Implemented Interfaces:

HandlerMethodArgumentResolver

Direct Known Subclasses:

ServletWebArgumentResolverAdapter

public abstract class AbstractWebArgumentResolverAdapter
extends Object
implements HandlerMethodArgumentResolver

An abstract base class adapting a WebArgumentResolver to the HandlerMethodArgumentResolver contract.

Note: This class is provided for backwards compatibility. However it is recommended to re-write a WebArgumentResolver as HandlerMethodArgumentResolver. Since supportsParameter(org.springframework.core.MethodParameter) can only be implemented by actually resolving the value and then checking the result is not WebArgumentResolver#UNRESOLVED any exceptions raised must be absorbed and ignored since it's not clear whether the adapter doesn't support the parameter or whether it failed for an internal reason. The HandlerMethodArgumentResolver contract also provides access to model attributes and to WebDataBinderFactory (for type conversion).

Since:

3.1

Author:

Arjen Poutsma, Rossen Stoyanchev

Constructor Summary

Constructors

Constructor	Description
AbstractWebArgumentResolverAdapter(WebArgumentResolver adaptee)	Create a new instance.

Method Summary

Modifier and Type	Method	Description
protected abstract NativeWebRequest	getWebRequest()	Required for access to NativeWebRequest in supportsParameter(org.springframework.core.MethodParameter).
@Nullable Object	resolveArgument(MethodParameter parameter, @Nullable ModelAndViewContainer mavContainer, NativeWebRequest webRequest, @Nullable WebDataBinderFactory binderFactory)	Delegate to the WebArgumentResolver instance.
boolean	supportsParameter(MethodParameter parameter)	Actually resolve the value and check the resolved value is not WebArgumentResolver.UNRESOLVED absorbing _any_ exceptions.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

AbstractWebArgumentResolverAdapter

public AbstractWebArgumentResolverAdapter(WebArgumentResolver adaptee)

Create a new instance.

Method Details

supportsParameter

public boolean supportsParameter(MethodParameter parameter)

Actually resolve the value and check the resolved value is not WebArgumentResolver.UNRESOLVED absorbing _any_ exceptions.

Specified by:

supportsParameter in interface HandlerMethodArgumentResolver

Parameters:

parameter - the method parameter to check

Returns:

true if this resolver supports the supplied parameter; false otherwise

resolveArgument

public @Nullable Object resolveArgument(MethodParameter parameter,
 @Nullable ModelAndViewContainer mavContainer,
 NativeWebRequest webRequest,
 @Nullable WebDataBinderFactory binderFactory)
                                 throws Exception

Delegate to the WebArgumentResolver instance.

Specified by:

resolveArgument in interface HandlerMethodArgumentResolver

Parameters:

parameter - the method parameter to resolve. This parameter must have previously been passed to HandlerMethodArgumentResolver.supportsParameter(org.springframework.core.MethodParameter) which must have returned true.

mavContainer - the ModelAndViewContainer for the current request

webRequest - the current request

binderFactory - a factory for creating WebDataBinder instances

Returns:

the resolved argument value, or null if not resolvable

Throws:

IllegalStateException - if the resolved value is not assignable to the method parameter.

Exception - in case of errors with the preparation of argument values

getWebRequest

protected abstract NativeWebRequest getWebRequest()

Required for access to NativeWebRequest in supportsParameter(org.springframework.core.MethodParameter).