public class ContentNegotiatingViewResolver extends WebApplicationObjectSupport implements ViewResolver, Ordered, InitializingBean
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 ViewResolver
s. 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 candidates, and still need have the content type requested (via file extension, parameter,
or Accept
header, described above).
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.
ViewResolver
,
InternalResourceViewResolver
,
BeanNameViewResolver
logger
HIGHEST_PRECEDENCE, LOWEST_PRECEDENCE
Constructor and Description |
---|
ContentNegotiatingViewResolver() |
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).
|
List<View> |
getDefaultViews() |
protected List<MediaType> |
getMediaTypes(HttpServletRequest request)
Determines the list of
MediaType for the given HttpServletRequest . |
int |
getOrder()
Get the order value of this object.
|
List<ViewResolver> |
getViewResolvers() |
protected void |
initServletContext(ServletContext servletContext)
Subclasses may override this for custom initialization based
on the ServletContext that this application object runs in.
|
boolean |
isUseNotAcceptableStatusCode()
Whether to return HTTP Status 406 if no suitable is found.
|
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 |
setDefaultViews(List<View> defaultViews)
Set the default views to use when a more specific view can not be obtained
from the
ViewResolver chain. |
void |
setOrder(int order) |
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.
|
getServletContext, getTempDir, getWebApplicationContext, initApplicationContext, isContextRequired, setServletContext
getApplicationContext, getMessageSourceAccessor, initApplicationContext, requiredContextClass, setApplicationContext
public void setOrder(int order)
public int getOrder()
Ordered
Higher values are interpreted as lower priority. As a consequence,
the object with the lowest value has the highest priority (somewhat
analogous to Servlet load-on-startup
values).
Same order values will result in arbitrary sort positions for the affected objects.
getOrder
in interface Ordered
Ordered.HIGHEST_PRECEDENCE
,
Ordered.LOWEST_PRECEDENCE
public void setContentNegotiationManager(ContentNegotiationManager contentNegotiationManager)
ContentNegotiationManager
to use to determine requested media types.
If not set, ContentNegotiationManager's default constructor will be used,
applying a HeaderContentNegotiationStrategy
.
public void setUseNotAcceptableStatusCode(boolean useNotAcceptableStatusCode)
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.
public boolean isUseNotAcceptableStatusCode()
public void setDefaultViews(List<View> defaultViews)
ViewResolver
chain.public void setViewResolvers(List<ViewResolver> viewResolvers)
If this property is not set, view resolvers will be detected automatically.
public List<ViewResolver> getViewResolvers()
protected void initServletContext(ServletContext servletContext)
WebApplicationObjectSupport
The default implementation is empty. Called by
WebApplicationObjectSupport.initApplicationContext(org.springframework.context.ApplicationContext)
as well as WebApplicationObjectSupport.setServletContext(javax.servlet.ServletContext)
.
initServletContext
in class WebApplicationObjectSupport
servletContext
- the ServletContext that this application object runs in
(never null
)public void afterPropertiesSet()
InitializingBean
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.
afterPropertiesSet
in interface InitializingBean
public View resolveViewName(String viewName, Locale locale) throws Exception
ViewResolver
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).
resolveViewName
in interface ViewResolver
viewName
- name of the view to resolvelocale
- Locale in which to resolve the view.
ViewResolvers that support internationalization should respect this.null
if not found
(optional, to allow for ViewResolver chaining)Exception
- if the view cannot be resolved
(typically in case of problems creating an actual View object)protected List<MediaType> getMediaTypes(HttpServletRequest request)
MediaType
for the given HttpServletRequest
.request
- the current servlet request