org.springframework.web.reactive.result.method.annotation

Class AbstractNamedValueArgumentResolver

java.lang.Object

org.springframework.web.reactive.result.method.HandlerMethodArgumentResolverSupport

org.springframework.web.reactive.result.method.annotation.AbstractNamedValueArgumentResolver

All Implemented Interfaces:

HandlerMethodArgumentResolver

Direct Known Subclasses:

AbstractNamedValueSyncArgumentResolver, SessionAttributeMethodArgumentResolver

public abstract class AbstractNamedValueArgumentResolver
extends HandlerMethodArgumentResolverSupport

Abstract base class for resolving method arguments from a named value. Request parameters, request headers, and path variables are examples of named values. Each may have a name, a required flag, and a default value.

Subclasses define how to do the following:

• Obtain named value information for a method parameter
• Resolve names into argument values
• Handle missing argument values when argument values are required
• Optionally handle a resolved value

A default value string can contain ${...} placeholders and Spring Expression Language #{...} expressions. For this to work a ConfigurableBeanFactory must be supplied to the class constructor.

Since:

5.0

Author:

Rossen Stoyanchev

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	AbstractNamedValueArgumentResolver.NamedValueInfo Represents the information about a named value, including name, whether it's required and a default value.

Field Summary

Fields inherited from class org.springframework.web.reactive.result.method.HandlerMethodArgumentResolverSupport

logger

Constructor Summary

Constructors

Constructor and Description
AbstractNamedValueArgumentResolver(ConfigurableBeanFactory factory, ReactiveAdapterRegistry registry) Create a new AbstractNamedValueArgumentResolver instance.

Method Summary

Modifier and Type	Method and Description
protected abstract AbstractNamedValueArgumentResolver.NamedValueInfo	createNamedValueInfo(MethodParameter parameter) Create the AbstractNamedValueArgumentResolver.NamedValueInfo object for the given method parameter.
protected void	handleMissingValue(String name, MethodParameter parameter) Invoked when a named value is required, but resolveName(String, MethodParameter, ServerWebExchange) returned null and there is no default value.
protected void	handleMissingValue(String name, MethodParameter parameter, ServerWebExchange exchange) Invoked when a named value is required, but resolveName(String, MethodParameter, ServerWebExchange) returned null and there is no default value.
protected void	handleResolvedValue(Object arg, String name, MethodParameter parameter, Model model, ServerWebExchange exchange) Invoked after a value is resolved.
reactor.core.publisher.Mono<Object>	resolveArgument(MethodParameter parameter, BindingContext bindingContext, ServerWebExchange exchange) Resolve the value for the method parameter.
protected abstract reactor.core.publisher.Mono<Object>	resolveName(String name, MethodParameter parameter, ServerWebExchange exchange) Resolve the given parameter type and value name into an argument value.

Methods inherited from class org.springframework.web.reactive.result.method.HandlerMethodArgumentResolverSupport

checkAnnotatedParamNoReactiveWrapper, checkParameterType, checkParameterTypeNoReactiveWrapper, getAdapterRegistry

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.springframework.web.reactive.result.method.HandlerMethodArgumentResolver

supportsParameter

Constructor Detail

AbstractNamedValueArgumentResolver

public AbstractNamedValueArgumentResolver(@Nullable
                                          ConfigurableBeanFactory factory,
                                          ReactiveAdapterRegistry registry)

Create a new AbstractNamedValueArgumentResolver instance.

Parameters:

factory - 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

registry - for checking reactive type wrappers

Method Detail

resolveArgument

public reactor.core.publisher.Mono<Object> resolveArgument(MethodParameter parameter,
                                                           BindingContext bindingContext,
                                                           ServerWebExchange exchange)

Description copied from interface: HandlerMethodArgumentResolver

Resolve the value for the method parameter.

Parameters:

parameter - the method parameter

bindingContext - the binding context to use

exchange - the current exchange

Returns:

Mono for the argument value, possibly empty

createNamedValueInfo

protected abstract AbstractNamedValueArgumentResolver.NamedValueInfo createNamedValueInfo(MethodParameter parameter)

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

Parameters:

parameter - the method parameter

Returns:

the named value information

resolveName

protected abstract reactor.core.publisher.Mono<Object> resolveName(String name,
                                                                   MethodParameter parameter,
                                                                   ServerWebExchange exchange)

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

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)

exchange - the current exchange

Returns:

the resolved argument (may be empty Mono)

handleMissingValue

protected void handleMissingValue(String name,
                                  MethodParameter parameter,
                                  ServerWebExchange exchange)

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

Parameters:

name - the name for the value

parameter - the method parameter

exchange - the current exchange

handleMissingValue

protected void handleMissingValue(String name,
                                  MethodParameter parameter)

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

Parameters:

name - the name for the value

parameter - the method parameter

handleResolvedValue

protected void handleResolvedValue(@Nullable
                                   Object arg,
                                   String name,
                                   MethodParameter parameter,
                                   Model model,
                                   ServerWebExchange exchange)

Invoked after a value is resolved.

Parameters:

arg - the resolved argument value

name - the argument name

parameter - the argument parameter type

model - the model

exchange - the current exchange