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(ConfigurableBeanFactory beanFactory)
Create a new ExpressionValueMethodArgumentResolver instance.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`protected AbstractNamedValueMethodArgumentResolver.NamedValueInfo`	`createNamedValueInfo(MethodParameter parameter)`	Create the `AbstractNamedValueMethodArgumentResolver.NamedValueInfo` object for the given method parameter.
`protected void`	`handleMissingValue(String name, 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, MethodParameter parameter, NativeWebRequest webRequest)`	Resolve the given parameter type and value name into an argument value.
`boolean`	`supportsParameter(MethodParameter parameter)`	Whether the given method parameter is supported by this resolver.

Methods inherited from class org.springframework.web.method.annotation.AbstractNamedValueMethodArgumentResolver
handleMissingValue, handleResolvedValue, resolveArgument

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - ExpressionValueMethodArgumentResolver
```
public ExpressionValueMethodArgumentResolver(@Nullable
                                             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 Detail
  - supportsParameter
```
public boolean supportsParameter(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(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,
                             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,
                                  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

Class ExpressionValueMethodArgumentResolver

Nested Class Summary

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

Constructor Summary

Method Summary

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

Methods inherited from class java.lang.Object

Constructor Detail

ExpressionValueMethodArgumentResolver

Method Detail

supportsParameter

createNamedValueInfo

resolveName

handleMissingValue