Package org.springframework.web.servlet.mvc.method.annotation

Class ServletModelAttributeMethodProcessor

java.lang.Object

org.springframework.web.method.annotation.ModelAttributeMethodProcessor

org.springframework.web.servlet.mvc.method.annotation.ServletModelAttributeMethodProcessor

All Implemented Interfaces:

HandlerMethodArgumentResolver, HandlerMethodReturnValueHandler

public class ServletModelAttributeMethodProcessor
extends ModelAttributeMethodProcessor

A Servlet-specific ModelAttributeMethodProcessor that applies data binding through a WebDataBinder of type ServletRequestDataBinder.

Also adds a fall-back strategy to instantiate the model attribute from a URI template variable or from a request parameter if the name matches the model attribute name and there is an appropriate type conversion strategy.

Since:

3.1

Author:

Rossen Stoyanchev, Juergen Hoeller

Field Summary

Fields inherited from class org.springframework.web.method.annotation.ModelAttributeMethodProcessor

logger

Constructor Summary

Constructors

Constructor	Description
ServletModelAttributeMethodProcessor(boolean annotationNotRequired)	Class constructor.

Method Summary

Modifier and Type	Method	Description
protected void	bindRequestParameters(WebDataBinder binder, NativeWebRequest request)	This implementation downcasts WebDataBinder to ServletRequestDataBinder before binding.
protected final Object	createAttribute(String attributeName, MethodParameter parameter, WebDataBinderFactory binderFactory, NativeWebRequest request)	Instantiate the model attribute from a URI template variable or from a request parameter if the name matches to the model attribute name and if there is an appropriate type conversion strategy.
protected Object	createAttributeFromRequestValue(String sourceValue, String attributeName, MethodParameter parameter, WebDataBinderFactory binderFactory, NativeWebRequest request)	Create a model attribute from a String request value (e.g.
protected String	getRequestValueForAttribute(String attributeName, NativeWebRequest request)	Obtain a value from the request that may be used to instantiate the model attribute through type conversion from String to the target type.
protected final Map<String,String>	getUriTemplateVariables(NativeWebRequest request)
Object	resolveConstructorArgument(String paramName, Class<?> paramType, NativeWebRequest request)

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

constructAttribute, handleReturnValue, isBindExceptionRequired, isBindExceptionRequired, resolveArgument, supportsParameter, supportsReturnType, validateIfApplicable, validateValueIfApplicable

Methods inherited from class java.lang.Object

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

Constructor Details

ServletModelAttributeMethodProcessor

public ServletModelAttributeMethodProcessor(boolean annotationNotRequired)

Class constructor.

Parameters:

annotationNotRequired - if "true", non-simple method arguments and return values are considered model attributes with or without a @ModelAttribute annotation

Method Details

createAttribute

protected final Object createAttribute(String attributeName,
 MethodParameter parameter,
 WebDataBinderFactory binderFactory,
 NativeWebRequest request)
                                throws Exception

Instantiate the model attribute from a URI template variable or from a request parameter if the name matches to the model attribute name and if there is an appropriate type conversion strategy. If none of these are true delegate back to the base class.

Overrides:

createAttribute in class ModelAttributeMethodProcessor

Parameters:

attributeName - the name of the attribute (never null)

parameter - the method parameter declaration

binderFactory - for creating WebDataBinder instance

request - the current request

Returns:

the created model attribute (never null)

Throws:

BindException - in case of constructor argument binding failure

Exception - in case of constructor invocation failure

See Also:

• createAttributeFromRequestValue(java.lang.String, java.lang.String, org.springframework.core.MethodParameter, org.springframework.web.bind.support.WebDataBinderFactory, org.springframework.web.context.request.NativeWebRequest)

getRequestValueForAttribute

@Nullable
protected String getRequestValueForAttribute(String attributeName,
 NativeWebRequest request)

Obtain a value from the request that may be used to instantiate the model attribute through type conversion from String to the target type.

The default implementation looks for the attribute name to match a URI variable first and then a request parameter.

Parameters:

attributeName - the model attribute name

request - the current request

Returns:

the request value to try to convert, or null if none

getUriTemplateVariables

protected final Map<String,String> getUriTemplateVariables(NativeWebRequest request)

createAttributeFromRequestValue

@Nullable
protected Object createAttributeFromRequestValue(String sourceValue,
 String attributeName,
 MethodParameter parameter,
 WebDataBinderFactory binderFactory,
 NativeWebRequest request)
                                          throws Exception

Create a model attribute from a String request value (e.g. URI template variable, request parameter) using type conversion.

The default implementation converts only if there a registered Converter that can perform the conversion.

Parameters:

sourceValue - the source value to create the model attribute from

attributeName - the name of the attribute (never null)

parameter - the method parameter

binderFactory - for creating WebDataBinder instance

request - the current request

Returns:

the created model attribute, or null if no suitable conversion found

Throws:

Exception

bindRequestParameters

protected void bindRequestParameters(WebDataBinder binder,
 NativeWebRequest request)

This implementation downcasts WebDataBinder to ServletRequestDataBinder before binding.

Overrides:

bindRequestParameters in class ModelAttributeMethodProcessor

Parameters:

binder - the data binder instance to use for the binding

request - the current request

See Also:

• ServletRequestDataBinderFactory

resolveConstructorArgument

@Nullable
public Object resolveConstructorArgument(String paramName,
 Class<?> paramType,
 NativeWebRequest request)
                                  throws Exception

Overrides:

resolveConstructorArgument in class ModelAttributeMethodProcessor

Throws:

Exception