Package org.springframework.web.method.annotation

Class ExpressionValueMethodArgumentResolver

java.lang.Object

org.springframework.web.method.annotation.AbstractNamedValueMethodArgumentResolver

org.springframework.web.method.annotation.ExpressionValueMethodArgumentResolver

All Implemented Interfaces:

HandlerMethodArgumentResolver

public class ExpressionValueMethodArgumentResolver
extends AbstractNamedValueMethodArgumentResolver

Resolves method arguments annotated with @Value.

An @Value does not have a name but gets resolved from the default value string, which may contain ${...} placeholder or Spring Expression Language #{...} expressions.

A WebDataBinder may be invoked to apply type conversion to resolved argument value.

Since:

3.1

Author:

Rossen Stoyanchev

Nested Class Summary

Nested classes/interfaces inherited from class org.springframework.web.method.annotation.AbstractNamedValueMethodArgumentResolver

AbstractNamedValueMethodArgumentResolver.NamedValueInfo

Constructor Summary

Constructors

Constructor	Description
ExpressionValueMethodArgumentResolver(org.springframework.beans.factory.config.ConfigurableBeanFactory beanFactory)	Create a new ExpressionValueMethodArgumentResolver instance.

Method Summary

Modifier and Type	Method	Description
protected AbstractNamedValueMethodArgumentResolver.NamedValueInfo	createNamedValueInfo(org.springframework.core.MethodParameter parameter)	Create the AbstractNamedValueMethodArgumentResolver.NamedValueInfo object for the given method parameter.
protected void	handleMissingValue(String name, org.springframework.core.MethodParameter parameter)	Invoked when a named value is required, but AbstractNamedValueMethodArgumentResolver.resolveName(String, MethodParameter, NativeWebRequest) returned null and there is no default value.
protected Object	resolveName(String name, org.springframework.core.MethodParameter parameter, NativeWebRequest webRequest)	Resolve the given parameter type and value name into an argument value.
boolean	supportsParameter(org.springframework.core.MethodParameter parameter)	Whether the given method parameter is supported by this resolver.

Methods inherited from class org.springframework.web.method.annotation.AbstractNamedValueMethodArgumentResolver

handleMissingValue, handleMissingValueAfterConversion, handleResolvedValue, resolveArgument

Methods inherited from class java.lang.Object

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

Constructor Details

ExpressionValueMethodArgumentResolver

public ExpressionValueMethodArgumentResolver(@Nullable
 org.springframework.beans.factory.config.ConfigurableBeanFactory beanFactory)

Create a new ExpressionValueMethodArgumentResolver instance.

Parameters:

beanFactory - a bean factory to use for resolving ${...} placeholder and #{...} SpEL expressions in default values; or null if default values are not expected to contain expressions

Method Details

supportsParameter

public boolean supportsParameter(org.springframework.core.MethodParameter parameter)

Description copied from interface: HandlerMethodArgumentResolver

Whether the given method parameter is supported by this resolver.

Parameters:

parameter - the method parameter to check

Returns:

true if this resolver supports the supplied parameter; false otherwise

createNamedValueInfo

protected AbstractNamedValueMethodArgumentResolver.NamedValueInfo createNamedValueInfo(org.springframework.core.MethodParameter parameter)

Description copied from class: AbstractNamedValueMethodArgumentResolver

Create the AbstractNamedValueMethodArgumentResolver.NamedValueInfo object for the given method parameter. Implementations typically retrieve the method annotation by means of MethodParameter.getParameterAnnotation(Class).

Specified by:

createNamedValueInfo in class AbstractNamedValueMethodArgumentResolver

Parameters:

parameter - the method parameter

Returns:

the named value information

resolveName

@Nullable
protected Object resolveName(String name,
 org.springframework.core.MethodParameter parameter,
 NativeWebRequest webRequest)
                      throws Exception

Description copied from class: AbstractNamedValueMethodArgumentResolver

Resolve the given parameter type and value name into an argument value.

Specified by:

resolveName in class AbstractNamedValueMethodArgumentResolver

Parameters:

name - the name of the value being resolved

parameter - the method parameter to resolve to an argument value (pre-nested in case of a Optional declaration)

webRequest - the current request

Returns:

the resolved argument (may be null)

Throws:

Exception - in case of errors

handleMissingValue

protected void handleMissingValue(String name,
 org.springframework.core.MethodParameter parameter)
                           throws ServletException

Description copied from class: AbstractNamedValueMethodArgumentResolver

Invoked when a named value is required, but AbstractNamedValueMethodArgumentResolver.resolveName(String, MethodParameter, NativeWebRequest) returned null and there is no default value. Subclasses typically throw an exception in this case.

Overrides:

handleMissingValue in class AbstractNamedValueMethodArgumentResolver

Parameters:

name - the name for the value

parameter - the method parameter

Throws:

ServletException