org.springframework.web.servlet.view

Class ContentNegotiatingViewResolver

java.lang.Object

org.springframework.context.support.ApplicationObjectSupport

org.springframework.web.context.support.WebApplicationObjectSupport

org.springframework.web.servlet.view.ContentNegotiatingViewResolver

All Implemented Interfaces:

Aware, InitializingBean, ApplicationContextAware, Ordered, ServletContextAware, ViewResolver

public class ContentNegotiatingViewResolver
extends WebApplicationObjectSupport
implements ViewResolver, Ordered, InitializingBean

Implementation of ViewResolver that resolves a view based on the request file name or Accept header.

The ContentNegotiatingViewResolver does not resolve views itself, but delegates to other ViewResolvers. By default, these other view resolvers are picked up automatically from the application context, though they can also be set explicitly by using the viewResolvers property. Note that in order for this view resolver to work properly, the order property needs to be set to a higher precedence than the others (the default is Ordered.HIGHEST_PRECEDENCE.)

This view resolver uses the requested media type to select a suitable View for a request. The requested media type is determined through the configured ContentNegotiationManager. Once the requested media type has been determined, this resolver queries each delegate view resolver for a View and determines if the requested media type is compatible with the view's content type). The most compatible view is returned.

Additionally, this view resolver exposes the defaultViews property, allowing you to override the views provided by the view resolvers. Note that these default views are offered as candicates, and still need have the content type requested (via file extension, parameter, or Accept header, described above). You can also set the default content type directly, which will be returned when the other mechanisms (Accept header, file extension or parameter) do not result in a match.

For example, if the request path is /view.html, this view resolver will look for a view that has the text/html content type (based on the html file extension). A request for /view with a text/html request Accept header has the same result.

Since:

3.0

Author:

Arjen Poutsma, Juergen Hoeller, Rossen Stoyanchev

See Also:

ViewResolver, InternalResourceViewResolver, BeanNameViewResolver

Field Summary

Fields inherited from interface org.springframework.core.Ordered

HIGHEST_PRECEDENCE, LOWEST_PRECEDENCE

Constructor Summary

Constructors

Constructor and Description
ContentNegotiatingViewResolver()

Method Summary

Methods

Modifier and Type	Method and Description
void	afterPropertiesSet() Invoked by a BeanFactory after it has set all bean properties supplied (and satisfied BeanFactoryAware and ApplicationContextAware).
protected List<MediaType>	getMediaTypes(HttpServletRequest request) Determines the list of MediaType for the given HttpServletRequest.
int	getOrder() Return the order value of this object, with a higher value meaning greater in terms of sorting.
protected void	initServletContext(ServletContext servletContext) Subclasses may override this for custom initialization based on the ServletContext that this application object runs in.
View	resolveViewName(String viewName, Locale locale) Resolve the given view by name.
void	setContentNegotiationManager(ContentNegotiationManager contentNegotiationManager) Set the ContentNegotiationManager to use to determine requested media types.
void	setDefaultContentType(MediaType defaultContentType) Deprecated. use setContentNegotiationManager(ContentNegotiationManager)
void	setDefaultViews(List<View> defaultViews) Set the default views to use when a more specific view can not be obtained from the ViewResolver chain.
void	setFavorParameter(boolean favorParameter) Deprecated. use setContentNegotiationManager(ContentNegotiationManager)
void	setFavorPathExtension(boolean favorPathExtension) Deprecated. use setContentNegotiationManager(ContentNegotiationManager)
void	setIgnoreAcceptHeader(boolean ignoreAcceptHeader) Deprecated. use setContentNegotiationManager(ContentNegotiationManager)
void	setMediaTypes(Map<String,String> mediaTypes) Deprecated. use setContentNegotiationManager(ContentNegotiationManager)
void	setOrder(int order)
void	setParameterName(String parameterName) Deprecated. use setContentNegotiationManager(ContentNegotiationManager)
void	setUseJaf(boolean useJaf) Deprecated. use setContentNegotiationManager(ContentNegotiationManager)
void	setUseNotAcceptableStatusCode(boolean useNotAcceptableStatusCode) Indicate whether a 406 Not Acceptable status code should be returned if no suitable view can be found.
void	setViewResolvers(List<ViewResolver> viewResolvers) Sets the view resolvers to be wrapped by this view resolver.

Methods inherited from class org.springframework.web.context.support.WebApplicationObjectSupport

getServletContext, getTempDir, getWebApplicationContext, initApplicationContext, isContextRequired, setServletContext

Methods inherited from class org.springframework.context.support.ApplicationObjectSupport

getApplicationContext, getMessageSourceAccessor, initApplicationContext, requiredContextClass, setApplicationContext

Methods inherited from class java.lang.Object

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

Constructor Detail

ContentNegotiatingViewResolver

public ContentNegotiatingViewResolver()

Method Detail

setOrder

public void setOrder(int order)

getOrder

public int getOrder()

Description copied from interface: Ordered

Return the order value of this object, with a higher value meaning greater in terms of sorting.

Normally starting with 0, with Integer.MAX_VALUE indicating the greatest value. Same order values will result in arbitrary positions for the affected objects.

Higher values can be interpreted as lower priority. As a consequence, the object with the lowest value has highest priority (somewhat analogous to Servlet "load-on-startup" values).

Specified by:

getOrder in interface Ordered

Returns:

the order value

setContentNegotiationManager

public void setContentNegotiationManager(ContentNegotiationManager contentNegotiationManager)

Set the ContentNegotiationManager to use to determine requested media types.

If not set, ContentNegotiationManager's default constructor will be used, applying a HeaderContentNegotiationStrategy.

See Also:

ContentNegotiationManager.ContentNegotiationManager()

setFavorPathExtension

@Deprecated
public void setFavorPathExtension(boolean favorPathExtension)

Deprecated. use setContentNegotiationManager(ContentNegotiationManager)

Indicate whether the extension of the request path should be used to determine the requested media type, in favor of looking at the Accept header. The default value is true.

For instance, when this flag is true (the default), a request for /hotels.pdf will result in an AbstractPdfView being resolved, while the Accept header can be the browser-defined text/html,application/xhtml+xml.

setUseJaf

@Deprecated
public void setUseJaf(boolean useJaf)

Deprecated. use setContentNegotiationManager(ContentNegotiationManager)

Indicate whether to use the Java Activation Framework to map from file extensions to media types.

Default is true, i.e. the Java Activation Framework is used (if available).

setFavorParameter

@Deprecated
public void setFavorParameter(boolean favorParameter)

Deprecated. use setContentNegotiationManager(ContentNegotiationManager)

Indicate whether a request parameter should be used to determine the requested media type, in favor of looking at the Accept header. The default value is false.

For instance, when this flag is true, a request for /hotels?format=pdf will result in an AbstractPdfView being resolved, while the Accept header can be the browser-defined text/html,application/xhtml+xml.

setParameterName

@Deprecated
public void setParameterName(String parameterName)

Deprecated. use setContentNegotiationManager(ContentNegotiationManager)

Set the parameter name that can be used to determine the requested media type if the setFavorParameter(boolean) property is true. The default parameter name is format.

setIgnoreAcceptHeader

@Deprecated
public void setIgnoreAcceptHeader(boolean ignoreAcceptHeader)

Deprecated. use setContentNegotiationManager(ContentNegotiationManager)

Indicate whether the HTTP Accept header should be ignored. Default is false.

If set to true, this view resolver will only refer to the file extension and/or parameter, as indicated by the favorPathExtension and favorParameter properties.

setMediaTypes

@Deprecated
public void setMediaTypes(Map<String,String> mediaTypes)

Deprecated. use setContentNegotiationManager(ContentNegotiationManager)

Set the mapping from file extensions to media types.

When this mapping is not set or when an extension is not present, this view resolver will fall back to using a FileTypeMap when the Java Action Framework is available.

setDefaultContentType

@Deprecated
public void setDefaultContentType(MediaType defaultContentType)

Deprecated. use setContentNegotiationManager(ContentNegotiationManager)

Set the default content type.

This content type will be used when file extension, parameter, nor Accept header define a content-type, either through being disabled or empty.

setUseNotAcceptableStatusCode

public void setUseNotAcceptableStatusCode(boolean useNotAcceptableStatusCode)

Indicate whether a 406 Not Acceptable status code should be returned if no suitable view can be found.

Default is false, meaning that this view resolver returns null for resolveViewName(String, Locale) when an acceptable view cannot be found. This will allow for view resolvers chaining. When this property is set to true, resolveViewName(String, Locale) will respond with a view that sets the response status to 406 Not Acceptable instead.

setDefaultViews

public void setDefaultViews(List<View> defaultViews)

Set the default views to use when a more specific view can not be obtained from the ViewResolver chain.

setViewResolvers

public void setViewResolvers(List<ViewResolver> viewResolvers)

Sets the view resolvers to be wrapped by this view resolver.

If this property is not set, view resolvers will be detected automatically.

initServletContext

protected void initServletContext(ServletContext servletContext)

Description copied from class: WebApplicationObjectSupport

Subclasses may override this for custom initialization based on the ServletContext that this application object runs in.

The default implementation is empty. Called by WebApplicationObjectSupport.initApplicationContext(org.springframework.context.ApplicationContext) as well as WebApplicationObjectSupport.setServletContext(javax.servlet.ServletContext).

Overrides:

initServletContext in class WebApplicationObjectSupport

Parameters:

servletContext - the ServletContext that this application object runs in (never null)

afterPropertiesSet

public void afterPropertiesSet()

Description copied from interface: InitializingBean

Invoked by a BeanFactory after it has set all bean properties supplied (and satisfied BeanFactoryAware and ApplicationContextAware).

This method allows the bean instance to perform initialization only possible when all bean properties have been set and to throw an exception in the event of misconfiguration.

Specified by:

afterPropertiesSet in interface InitializingBean

resolveViewName

public View resolveViewName(String viewName,
                   Locale locale)
                     throws Exception

Description copied from interface: ViewResolver

Resolve the given view by name.

Note: To allow for ViewResolver chaining, a ViewResolver should return null if a view with the given name is not defined in it. However, this is not required: Some ViewResolvers will always attempt to build View objects with the given name, unable to return null (rather throwing an exception when View creation failed).

Specified by:

resolveViewName in interface ViewResolver

Parameters:

viewName - name of the view to resolve

locale - Locale in which to resolve the view. ViewResolvers that support internationalization should respect this.

Returns:

the View object, or null if not found (optional, to allow for ViewResolver chaining)

Throws:

Exception - if the view cannot be resolved (typically in case of problems creating an actual View object)

getMediaTypes

protected List<MediaType> getMediaTypes(HttpServletRequest request)

Determines the list of MediaType for the given HttpServletRequest.

Parameters:

request - the current servlet request

Returns:

the list of media types requested, if any