Package org.springframework.web.accept

Class ContentNegotiationManager

java.lang.Object

org.springframework.web.accept.ContentNegotiationManager

All Implemented Interfaces:

ContentNegotiationStrategy, MediaTypeFileExtensionResolver

public class ContentNegotiationManager
extends Object
implements ContentNegotiationStrategy, MediaTypeFileExtensionResolver

Central class to determine requested media types for a request. This is done by delegating to a list of configured ContentNegotiationStrategy instances.

Also provides methods to look up file extensions for a media type. This is done by delegating to the list of configured MediaTypeFileExtensionResolver instances.

Since:

3.2

Author:

Rossen Stoyanchev, Juergen Hoeller

Field Summary

Fields inherited from interface org.springframework.web.accept.ContentNegotiationStrategy

MEDIA_TYPE_ALL_LIST

Constructor Summary

Constructors

Constructor	Description
ContentNegotiationManager()	Create a default instance with a HeaderContentNegotiationStrategy.
ContentNegotiationManager(Collection<ContentNegotiationStrategy> strategies)	A collection-based alternative to ContentNegotiationManager(ContentNegotiationStrategy...).
ContentNegotiationManager(ContentNegotiationStrategy... strategies)	Create an instance with the given list of ContentNegotiationStrategy strategies each of which may also be an instance of MediaTypeFileExtensionResolver.

Method Summary

Modifier and Type	Method	Description
void	addFileExtensionResolvers(MediaTypeFileExtensionResolver... resolvers)	Register more MediaTypeFileExtensionResolver instances in addition to those detected at construction.
List<String>	getAllFileExtensions()	Get all registered file extensions.
Map<String,MediaType>	getMediaTypeMappings()	Return all registered lookup key to media type mappings by iterating MediaTypeFileExtensionResolvers.
List<ContentNegotiationStrategy>	getStrategies()	Return the configured content negotiation strategies.
<T extends ContentNegotiationStrategy> T	getStrategy(Class<T> strategyType)	Find a ContentNegotiationStrategy of the given type.
List<String>	resolveFileExtensions(MediaType mediaType)	Resolve the given media type to a list of file extensions.
List<MediaType>	resolveMediaTypes(NativeWebRequest request)	Resolve the given request to a list of media types.

Methods inherited from class java.lang.Object

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

Constructor Details

ContentNegotiationManager

public ContentNegotiationManager(ContentNegotiationStrategy... strategies)

Create an instance with the given list of ContentNegotiationStrategy strategies each of which may also be an instance of MediaTypeFileExtensionResolver.

Parameters:

strategies - the strategies to use

ContentNegotiationManager

public ContentNegotiationManager(Collection<ContentNegotiationStrategy> strategies)

A collection-based alternative to ContentNegotiationManager(ContentNegotiationStrategy...).

Parameters:

strategies - the strategies to use

Since:

3.2.2

ContentNegotiationManager

public ContentNegotiationManager()

Create a default instance with a HeaderContentNegotiationStrategy.

Method Details

getStrategies

public List<ContentNegotiationStrategy> getStrategies()

Return the configured content negotiation strategies.

Since:

3.2.16

getStrategy

@Nullable
public <T extends ContentNegotiationStrategy> T getStrategy(Class<T> strategyType)

Find a ContentNegotiationStrategy of the given type.

Parameters:

strategyType - the strategy type

Returns:

the first matching strategy, or null if none

Since:

4.3

addFileExtensionResolvers

public void addFileExtensionResolvers(MediaTypeFileExtensionResolver... resolvers)

Register more MediaTypeFileExtensionResolver instances in addition to those detected at construction.

Parameters:

resolvers - the resolvers to add

resolveMediaTypes

public List<MediaType> resolveMediaTypes(NativeWebRequest request)
                                  throws HttpMediaTypeNotAcceptableException

Description copied from interface: ContentNegotiationStrategy

Resolve the given request to a list of media types. The returned list is ordered by specificity first and by quality parameter second.

Specified by:

resolveMediaTypes in interface ContentNegotiationStrategy

Parameters:

request - the current request

Returns:

the requested media types, or ContentNegotiationStrategy.MEDIA_TYPE_ALL_LIST if none were requested.

Throws:

HttpMediaTypeNotAcceptableException - if the requested media types cannot be parsed

resolveFileExtensions

public List<String> resolveFileExtensions(MediaType mediaType)

Description copied from interface: MediaTypeFileExtensionResolver

Resolve the given media type to a list of file extensions.

Specified by:

resolveFileExtensions in interface MediaTypeFileExtensionResolver

Parameters:

mediaType - the media type to resolve

Returns:

a list of extensions or an empty list (never null)

getAllFileExtensions

public List<String> getAllFileExtensions()

Get all registered file extensions.

At startup this method returns extensions explicitly registered with either PathExtensionContentNegotiationStrategy or ParameterContentNegotiationStrategy. At runtime if there is a "path extension" strategy and its useRegisteredExtensionsOnly property is set to "false", the list of extensions may increase as file extensions are resolved via MediaTypeFactory and cached.

Specified by:

getAllFileExtensions in interface MediaTypeFileExtensionResolver

Returns:

a list of extensions or an empty list (never null)

getMediaTypeMappings

public Map<String,MediaType> getMediaTypeMappings()

Return all registered lookup key to media type mappings by iterating MediaTypeFileExtensionResolvers.

Since:

5.2.4