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

Class AbstractNamedValueArgumentResolver

java.lang.Object

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

All Implemented Interfaces:

HandlerMethodArgumentResolver

Direct Known Subclasses:

AbstractNamedValueSyncArgumentResolver, SessionAttributeMethodArgumentResolver

public abstract class AbstractNamedValueArgumentResolver
extends java.lang.Object
implements HandlerMethodArgumentResolver

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

Modifier and Type	Field and Description
private ConfigurableBeanFactory	configurableBeanFactory
private BeanExpressionContext	expressionContext
private java.util.Map<MethodParameter,AbstractNamedValueArgumentResolver.NamedValueInfo>	namedValueInfoCache

Constructor Summary

Constructors

Constructor and Description
AbstractNamedValueArgumentResolver(ConfigurableBeanFactory beanFactory)

Method Summary

Modifier and Type	Method and Description
private java.lang.Object	applyConversion(java.lang.Object value, AbstractNamedValueArgumentResolver.NamedValueInfo namedValueInfo, MethodParameter parameter, BindingContext bindingContext, ServerWebExchange exchange)
protected abstract AbstractNamedValueArgumentResolver.NamedValueInfo	createNamedValueInfo(MethodParameter parameter) Create the AbstractNamedValueArgumentResolver.NamedValueInfo object for the given method parameter.
private <any>	getDefaultValue(AbstractNamedValueArgumentResolver.NamedValueInfo namedValueInfo, MethodParameter parameter, BindingContext bindingContext, Model model, ServerWebExchange exchange)
private AbstractNamedValueArgumentResolver.NamedValueInfo	getNamedValueInfo(MethodParameter parameter) Obtain the named value for the given method parameter.
protected void	handleMissingValue(java.lang.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(java.lang.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.
private java.lang.Object	handleNullValue(java.lang.String name, java.lang.Object value, java.lang.Class<?> paramType) A null results in a false value for booleans or an exception for other primitives.
protected void	handleResolvedValue(java.lang.Object arg, java.lang.String name, MethodParameter parameter, Model model, ServerWebExchange exchange) Invoked after a value is resolved.
<any>	resolveArgument(MethodParameter parameter, BindingContext bindingContext, ServerWebExchange exchange) The returned Mono may produce one or zero values if the argument does not resolve to any value, which will result in null passed as the argument value.
protected abstract <any>	resolveName(java.lang.String name, MethodParameter parameter, ServerWebExchange exchange) Resolve the given parameter type and value name into an argument value.
private java.lang.Object	resolveStringValue(java.lang.String value) Resolve the given annotation-specified value, potentially containing placeholders and expressions.
private AbstractNamedValueArgumentResolver.NamedValueInfo	updateNamedValueInfo(MethodParameter parameter, AbstractNamedValueArgumentResolver.NamedValueInfo info) Create a new NamedValueInfo based on the given NamedValueInfo with sanitized values.

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

Field Detail

configurableBeanFactory

private final ConfigurableBeanFactory configurableBeanFactory

expressionContext

private final BeanExpressionContext expressionContext

namedValueInfoCache

private final java.util.Map<MethodParameter,AbstractNamedValueArgumentResolver.NamedValueInfo> namedValueInfoCache

Constructor Detail

AbstractNamedValueArgumentResolver

public AbstractNamedValueArgumentResolver(ConfigurableBeanFactory beanFactory)

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

resolveArgument

public <any> resolveArgument(MethodParameter parameter,
                             BindingContext bindingContext,
                             ServerWebExchange exchange)

Description copied from interface: HandlerMethodArgumentResolver

The returned Mono may produce one or zero values if the argument does not resolve to any value, which will result in null passed as the argument value.

Specified by:

resolveArgument in interface HandlerMethodArgumentResolver

Parameters:

parameter - the method parameter

bindingContext - the binding context to use

exchange - the current exchange

getNamedValueInfo

private AbstractNamedValueArgumentResolver.NamedValueInfo getNamedValueInfo(MethodParameter parameter)

Obtain the named value for the given method parameter.

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

updateNamedValueInfo

private AbstractNamedValueArgumentResolver.NamedValueInfo updateNamedValueInfo(MethodParameter parameter,
                                                                               AbstractNamedValueArgumentResolver.NamedValueInfo info)

Create a new NamedValueInfo based on the given NamedValueInfo with sanitized values.

resolveStringValue

private java.lang.Object resolveStringValue(java.lang.String value)

Resolve the given annotation-specified value, potentially containing placeholders and expressions.

resolveName

protected abstract <any> resolveName(java.lang.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 null)

applyConversion

private java.lang.Object applyConversion(java.lang.Object value,
                                         AbstractNamedValueArgumentResolver.NamedValueInfo namedValueInfo,
                                         MethodParameter parameter,
                                         BindingContext bindingContext,
                                         ServerWebExchange exchange)

getDefaultValue

private <any> getDefaultValue(AbstractNamedValueArgumentResolver.NamedValueInfo namedValueInfo,
                              MethodParameter parameter,
                              BindingContext bindingContext,
                              Model model,
                              ServerWebExchange exchange)

handleMissingValue

protected void handleMissingValue(java.lang.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(java.lang.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

handleNullValue

private java.lang.Object handleNullValue(java.lang.String name,
                                         java.lang.Object value,
                                         java.lang.Class<?> paramType)

A null results in a false value for booleans or an exception for other primitives.

handleResolvedValue

protected void handleResolvedValue(java.lang.Object arg,
                                   java.lang.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