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

This class is used to determine the requested media types of a request by delegating to a list of ContentNegotiationStrategy instances. The strategies must be provided at instantiation or alternatively if using the default constructor, an instance of HeaderContentNegotiationStrategy will be configured by default.

This class may also be used to look up file extensions associated with a MediaType. This is done by consulting the list of configured MediaTypeFileExtensionResolver instances. Note that some ContentNegotiationStrategy implementations also implement MediaTypeFileExtensionResolver and the class constructor accepting the former will also detect if they implement the latter. If you need to register additional resolvers, you can use the method addFileExtensionResolvers(MediaTypeFileExtensionResolver...).

Since:

3.2

Author:

Rossen Stoyanchev

Constructor Summary

Constructors

Constructor and Description
ContentNegotiationManager() Create an instance with a HeaderContentNegotiationStrategy.
ContentNegotiationManager(ContentNegotiationStrategy... strategies) Create an instance with the given ContentNegotiationStrategy instances.

Method Summary

Methods

Modifier and Type	Method and Description
void	addFileExtensionResolvers(MediaTypeFileExtensionResolver... resolvers) Add MediaTypeFileExtensionResolver instances.
List<String>	getAllFileExtensions() Delegate to all configured MediaTypeFileExtensionResolver instances and aggregate the list of all known file extensions.
List<String>	resolveFileExtensions(MediaType mediaType) Delegate to all configured MediaTypeFileExtensionResolver instances and aggregate the list of all file extensions found.
List<MediaType>	resolveMediaTypes(NativeWebRequest webRequest) Delegate to all configured ContentNegotiationStrategy instances until one returns a non-empty list.

Methods inherited from class java.lang.Object

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

Constructor Detail

ContentNegotiationManager

public ContentNegotiationManager(ContentNegotiationStrategy... strategies)

Create an instance with the given ContentNegotiationStrategy instances.

Each instance is checked to see if it is also an implementation of MediaTypeFileExtensionResolver, and if so it is registered as such.

Parameters:

strategies - one more more ContentNegotiationStrategy instances

ContentNegotiationManager

public ContentNegotiationManager()

Create an instance with a HeaderContentNegotiationStrategy.

Method Detail

addFileExtensionResolvers

public void addFileExtensionResolvers(MediaTypeFileExtensionResolver... resolvers)

Add MediaTypeFileExtensionResolver instances.

Note that some ContentNegotiationStrategy implementations also implement MediaTypeFileExtensionResolver and the class constructor accepting the former will also detect implementations of the latter. Therefore you only need to use this method to register additional instances.

Parameters:

resolvers - one or more resolvers

resolveMediaTypes

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

Delegate to all configured ContentNegotiationStrategy instances until one returns a non-empty list.

Specified by:

resolveMediaTypes in interface ContentNegotiationStrategy

Parameters:

webRequest - the current request

Returns:

the requested media types or an empty list, never null

Throws:

HttpMediaTypeNotAcceptableException - if the requested media types cannot be parsed

resolveFileExtensions

public List<String> resolveFileExtensions(MediaType mediaType)

Delegate to all configured MediaTypeFileExtensionResolver instances and aggregate the list of all file extensions found.

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()

Delegate to all configured MediaTypeFileExtensionResolver instances and aggregate the list of all known file extensions.

Specified by:

getAllFileExtensions in interface MediaTypeFileExtensionResolver

Returns:

a list of extensions or an empty list, never null