java.lang.Object
- org.springframework.web.method.annotation.AbstractNamedValueMethodArgumentResolver
- - org.springframework.web.method.annotation.RequestParamMethodArgumentResolver

所有已实现的接口:
HandlerMethodArgumentResolver, UriComponentsContributor
```
public class RequestParamMethodArgumentResolver
extends AbstractNamedValueMethodArgumentResolver
implements UriComponentsContributor
```
Resolves method arguments annotated with @RequestParam, arguments of type MultipartFile in conjunction with Spring's MultipartResolver abstraction, and arguments of type javax.servlet.http.Part in conjunction with Servlet 3.0 multipart requests. This resolver can also be created in default resolution mode in which simple types (int, long, etc.) not annotated with @RequestParam are also treated as request parameters with the parameter name derived from the argument name.
If the method parameter type is Map, the name specified in the annotation is used to resolve the request parameter String value. The value is then converted to a Map via type conversion assuming a suitable Converter or PropertyEditor has been registered. Or if a request parameter name is not specified the RequestParamMapMethodArgumentResolver is used instead to provide access to all request parameters in the form of a map.
A WebDataBinder is invoked to apply type conversion to resolved request header values that don't yet match the method parameter type.
从以下版本开始:
3.1
作者:
Arjen Poutsma, Rossen Stoyanchev, Brian Clozel
另请参阅:
RequestParamMapMethodArgumentResolver

嵌套类概要
- 从类继承的嵌套类/接口 org.springframework.web.method.annotation.AbstractNamedValueMethodArgumentResolver
  AbstractNamedValueMethodArgumentResolver.NamedValueInfo

构造器概要

构造器
构造器	说明
`RequestParamMethodArgumentResolver(boolean useDefaultResolution)`	Create a new `RequestParamMethodArgumentResolver` instance.
`RequestParamMethodArgumentResolver(ConfigurableBeanFactory beanFactory, boolean useDefaultResolution)`	Create a new `RequestParamMethodArgumentResolver` instance.

方法概要

所有方法实例方法具体方法
修饰符和类型	方法	说明
`void`	`contributeMethodArgument(MethodParameter parameter, Object value, UriComponentsBuilder builder, Map<String,Object> uriVariables, ConversionService conversionService)`	Process the given method argument and either update the `UriComponentsBuilder` or add to the map with URI variables to use to expand the URI after all arguments are processed.
`protected AbstractNamedValueMethodArgumentResolver.NamedValueInfo`	`createNamedValueInfo(MethodParameter parameter)`	Create the `AbstractNamedValueMethodArgumentResolver.NamedValueInfo` object for the given method parameter.
`protected String`	`formatUriValue(ConversionService cs, TypeDescriptor sourceType, Object value)`
`protected void`	`handleMissingValue(String name, MethodParameter parameter, NativeWebRequest request)`	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 request)`	Resolve the given parameter type and value name into an argument value.
`boolean`	`supportsParameter(MethodParameter parameter)`	Supports the following: @RequestParam-annotated method arguments.

从类继承的方法 org.springframework.web.method.annotation.AbstractNamedValueMethodArgumentResolver
handleMissingValue, handleResolvedValue, resolveArgument

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- 构造器详细资料
  - RequestParamMethodArgumentResolver
```
public RequestParamMethodArgumentResolver(boolean useDefaultResolution)
```
    Create a new RequestParamMethodArgumentResolver instance.
    参数:
    useDefaultResolution - in default resolution mode a method argument that is a simple type, as defined in BeanUtils.isSimpleProperty(java.lang.Class<?>), is treated as a request parameter even if it isn't annotated, the request parameter name is derived from the method parameter name.
  - RequestParamMethodArgumentResolver
```
public RequestParamMethodArgumentResolver(@Nullable
                                          ConfigurableBeanFactory beanFactory,
                                          boolean useDefaultResolution)
```
    Create a new RequestParamMethodArgumentResolver instance.
    参数:
    beanFactory - a bean factory used for resolving ${...} placeholder and #{...} SpEL expressions in default values, or null if default values are not expected to contain expressions
    useDefaultResolution - in default resolution mode a method argument that is a simple type, as defined in BeanUtils.isSimpleProperty(java.lang.Class<?>), is treated as a request parameter even if it isn't annotated, the request parameter name is derived from the method parameter name.
- 方法详细资料
  - supportsParameter
```
public boolean supportsParameter(MethodParameter parameter)
```
    Supports the following:
    @RequestParam-annotated method arguments. This excludes Map params where the annotation does not specify a name. See RequestParamMapMethodArgumentResolver instead for such params.
    Arguments of type MultipartFile unless annotated with @RequestPart.
    Arguments of type Part unless annotated with @RequestPart.
    In default resolution mode, simple type arguments even if not with @RequestParam.
    指定者:
    supportsParameter 在接口中 HandlerMethodArgumentResolver
    指定者:
    supportsParameter 在接口中 UriComponentsContributor
    参数:
    parameter - the method parameter to check
    返回:
    true if this resolver supports the supplied parameter; false otherwise
  - createNamedValueInfo
```
protected AbstractNamedValueMethodArgumentResolver.NamedValueInfo createNamedValueInfo(MethodParameter parameter)
```
    从类复制的说明: AbstractNamedValueMethodArgumentResolver
    Create the AbstractNamedValueMethodArgumentResolver.NamedValueInfo object for the given method parameter. Implementations typically retrieve the method annotation by means of MethodParameter.getParameterAnnotation(Class).
    指定者:
    createNamedValueInfo 在类中 AbstractNamedValueMethodArgumentResolver
    参数:
    parameter - the method parameter
    返回:
    the named value information
  - resolveName
```
@Nullable
protected Object resolveName(String name,
                             MethodParameter parameter,
                             NativeWebRequest request)
                      throws Exception
```
    从类复制的说明: AbstractNamedValueMethodArgumentResolver
    Resolve the given parameter type and value name into an argument value.
    指定者:
    resolveName 在类中 AbstractNamedValueMethodArgumentResolver
    参数:
    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)
    request - the current request
    返回:
    the resolved argument (may be null)
    抛出:
    Exception - in case of errors
  - handleMissingValue
```
protected void handleMissingValue(String name,
                                  MethodParameter parameter,
                                  NativeWebRequest request)
                           throws Exception
```
    从类复制的说明: 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.
    覆盖:
    handleMissingValue 在类中 AbstractNamedValueMethodArgumentResolver
    参数:
    name - the name for the value
    parameter - the method parameter
    request - the current request
    抛出:
    Exception
  - contributeMethodArgument
```
public void contributeMethodArgument(MethodParameter parameter,
                                     @Nullable
                                     Object value,
                                     UriComponentsBuilder builder,
                                     Map<String,Object> uriVariables,
                                     ConversionService conversionService)
```
    从接口复制的说明: UriComponentsContributor
    Process the given method argument and either update the UriComponentsBuilder or add to the map with URI variables to use to expand the URI after all arguments are processed.
    指定者:
    contributeMethodArgument 在接口中 UriComponentsContributor
    参数:
    parameter - the controller method parameter (never null)
    value - the argument value (possibly null)
    builder - the builder to update (never null)
    uriVariables - a map to add URI variables to (never null)
    conversionService - a ConversionService to format values as Strings
  - formatUriValue
```
@Nullable
protected String formatUriValue(@Nullable
                                ConversionService cs,
                                @Nullable
                                TypeDescriptor sourceType,
                                @Nullable
                                Object value)
```

类 RequestParamMethodArgumentResolver

嵌套类概要

从类继承的嵌套类/接口 org.springframework.web.method.annotation.AbstractNamedValueMethodArgumentResolver

构造器概要

方法概要

从类继承的方法 org.springframework.web.method.annotation.AbstractNamedValueMethodArgumentResolver

从类继承的方法 java.lang.Object

构造器详细资料

RequestParamMethodArgumentResolver

RequestParamMethodArgumentResolver

方法详细资料

supportsParameter

createNamedValueInfo

resolveName

handleMissingValue

contributeMethodArgument

formatUriValue