类 AbstractNamedValueMethodArgumentResolver
- java.lang.Object
- org.springframework.messaging.handler.annotation.reactive.AbstractNamedValueMethodArgumentResolver
public abstract class AbstractNamedValueMethodArgumentResolver extends Object implements SyncHandlerMethodArgumentResolver
Abstract base class to resolve method arguments from a named value, e.g. message headers or destination variables. Named values could have one or more of a name, a required flag, and a default value.Subclasses only need to define specific steps such as how to obtain named value details from a method parameter, how to resolve to argument values, or how to handle missing values.
A default value string can contain ${...} placeholders and Spring Expression Language
#{...}
expressions which will be resolved if aConfigurableBeanFactory
is supplied to the class constructor.A
ConversionService
is used to convert a resolved String argument value to the expected target method parameter type.- 从以下版本开始:
- 5.2
- 作者:
- Rossen Stoyanchev
嵌套类概要
嵌套类 修饰符和类型 类 说明 protected static class
AbstractNamedValueMethodArgumentResolver.NamedValueInfo
Represents a named value declaration.
构造器概要
构造器 限定符 构造器 说明 protected
AbstractNamedValueMethodArgumentResolver(ConversionService conversionService, ConfigurableBeanFactory beanFactory)
Constructor with aConversionService
and aBeanFactory
.
方法概要
所有方法 实例方法 抽象方法 具体方法 修饰符和类型 方法 说明 protected abstract AbstractNamedValueMethodArgumentResolver.NamedValueInfo
createNamedValueInfo(MethodParameter parameter)
Create theAbstractNamedValueMethodArgumentResolver.NamedValueInfo
object for the given method parameter.protected abstract void
handleMissingValue(String name, MethodParameter parameter, Message<?> message)
Invoked when a value is required, butresolveArgumentInternal(org.springframework.core.MethodParameter, org.springframework.messaging.Message<?>, java.lang.String)
returnednull
and there is no default value.protected abstract Object
resolveArgumentInternal(MethodParameter parameter, Message<?> message, String name)
Resolves the given parameter type and value name into an argument value.Object
resolveArgumentValue(MethodParameter parameter, Message<?> message)
Resolve the value for the method parameter synchronously.从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
从接口继承的方法 org.springframework.messaging.handler.invocation.reactive.HandlerMethodArgumentResolver
supportsParameter
从接口继承的方法 org.springframework.messaging.handler.invocation.reactive.SyncHandlerMethodArgumentResolver
resolveArgument
构造器详细资料
AbstractNamedValueMethodArgumentResolver
protected AbstractNamedValueMethodArgumentResolver(ConversionService conversionService, @Nullable ConfigurableBeanFactory beanFactory)
Constructor with aConversionService
and aBeanFactory
.- 参数:
conversionService
- conversion service for converting String values to the target method parameter typebeanFactory
- a bean factory for resolving${...}
placeholders and#{...}
SpEL expressions in default values
方法详细资料
resolveArgumentValue
public Object resolveArgumentValue(MethodParameter parameter, Message<?> message)
从接口复制的说明:SyncHandlerMethodArgumentResolver
Resolve the value for the method parameter synchronously.- 指定者:
resolveArgumentValue
在接口中SyncHandlerMethodArgumentResolver
- 参数:
parameter
- the method parametermessage
- the currently processed message- 返回:
- the resolved value, if any
createNamedValueInfo
protected abstract AbstractNamedValueMethodArgumentResolver.NamedValueInfo createNamedValueInfo(MethodParameter parameter)
Create theAbstractNamedValueMethodArgumentResolver.NamedValueInfo
object for the given method parameter. Implementations typically retrieve the method annotation by means ofMethodParameter.getParameterAnnotation(Class)
.- 参数:
parameter
- the method parameter- 返回:
- the named value information
resolveArgumentInternal
@Nullable protected abstract Object resolveArgumentInternal(MethodParameter parameter, Message<?> message, String name)
Resolves the given parameter type and value name into an argument value.- 参数:
parameter
- the method parameter to resolve to an argument valuemessage
- the current requestname
- the name of the value being resolved- 返回:
- the resolved argument. May be
null
handleMissingValue
protected abstract void handleMissingValue(String name, MethodParameter parameter, Message<?> message)
Invoked when a value is required, butresolveArgumentInternal(org.springframework.core.MethodParameter, org.springframework.messaging.Message<?>, java.lang.String)
returnednull
and there is no default value. Sub-classes can throw an appropriate exception for this case.- 参数:
name
- the name for the valueparameter
- the target method parametermessage
- the message being processed