Class AbstractCachingViewResolver
- All Implemented Interfaces:
Aware
,ApplicationContextAware
,ServletContextAware
,ViewResolver
- Direct Known Subclasses:
ResourceBundleViewResolver
,UrlBasedViewResolver
,XmlViewResolver
ViewResolver
implementations. Caches View
objects
once resolved: This means that view resolution won't be a performance problem,
no matter how costly initial view retrieval is.
Subclasses need to implement the loadView(java.lang.String, java.util.Locale)
template method,
building the View object for a specific view name and locale.
- Author:
- Rod Johnson, Juergen Hoeller
- See Also:
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Nested Class Summary
Modifier and TypeClassDescriptionstatic interface
Filter that determines if view should be cached. -
Field Summary
Modifier and TypeFieldDescriptionstatic final int
Default maximum number of entries for the view cache: 1024.Fields inherited from class org.springframework.context.support.ApplicationObjectSupport
logger
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionvoid
Clear the entire view cache, removing all cached view objects.protected View
createView
(String viewName, Locale locale) Create the actual View object.Return filter function that determines if view should be cached.protected Object
getCacheKey
(String viewName, Locale locale) Return the cache key for the given view name and the given locale.int
Return the maximum number of entries for the view cache.boolean
isCache()
Return if caching is enabled.boolean
Return if caching of unresolved views is enabled.protected abstract View
Subclasses must implement this method, building a View object for the specified view.void
removeFromCache
(String viewName, Locale locale) Provides functionality to clear the cache for a certain view.resolveViewName
(String viewName, Locale locale) Resolve the given view by name.void
setCache
(boolean cache) Enable or disable caching.void
setCacheFilter
(AbstractCachingViewResolver.CacheFilter cacheFilter) Set the filter that determines if view should be cached.void
setCacheLimit
(int cacheLimit) Specify the maximum number of entries for the view cache.void
setCacheUnresolved
(boolean cacheUnresolved) Whether a view name once resolved tonull
should be cached and automatically resolved tonull
subsequently.Methods inherited from class org.springframework.web.context.support.WebApplicationObjectSupport
getServletContext, getTempDir, getWebApplicationContext, initApplicationContext, initServletContext, isContextRequired, setServletContext
Methods inherited from class org.springframework.context.support.ApplicationObjectSupport
getApplicationContext, getMessageSourceAccessor, initApplicationContext, obtainApplicationContext, requiredContextClass, setApplicationContext
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Field Details
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DEFAULT_CACHE_LIMIT
public static final int DEFAULT_CACHE_LIMITDefault maximum number of entries for the view cache: 1024.- See Also:
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Constructor Details
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AbstractCachingViewResolver
public AbstractCachingViewResolver()
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Method Details
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setCacheLimit
public void setCacheLimit(int cacheLimit) Specify the maximum number of entries for the view cache. Default is 1024. -
getCacheLimit
public int getCacheLimit()Return the maximum number of entries for the view cache. -
setCache
public void setCache(boolean cache) Enable or disable caching.This is equivalent to setting the
"cacheLimit"
property to the default limit (1024) or to 0, respectively.Default is "true": caching is enabled. Disable this only for debugging and development.
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isCache
public boolean isCache()Return if caching is enabled. -
setCacheUnresolved
public void setCacheUnresolved(boolean cacheUnresolved) Whether a view name once resolved tonull
should be cached and automatically resolved tonull
subsequently.Default is "true": unresolved view names are cached. Note that this flag only applies if the general
"cache"
flag is kept at its default of "true" as well.Of specific interest is the ability for some
AbstractUrlBasedView
implementations (e.g., FreeMarker) to check if an underlying resource exists viaAbstractUrlBasedView.checkResource(Locale)
. With this flag set to "false", an underlying resource that re-appears is noticed and used. With the flag set to "true", only one check is made. -
isCacheUnresolved
public boolean isCacheUnresolved()Return if caching of unresolved views is enabled. -
setCacheFilter
Set the filter that determines if view should be cached.Default behaviour is to cache all views.
- Since:
- 5.2
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getCacheFilter
Return filter function that determines if view should be cached.- Since:
- 5.2
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resolveViewName
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 returnnull
(rather throwing an exception when View creation failed).- Specified by:
resolveViewName
in interfaceViewResolver
- Parameters:
viewName
- name of the view to resolvelocale
- the 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)
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getCacheKey
Return the cache key for the given view name and the given locale.Default is a String consisting of view name and locale suffix. Can be overridden in subclasses.
Needs to respect the locale in general, as a different locale can lead to a different view resource.
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removeFromCache
Provides functionality to clear the cache for a certain view.This can be handy in case developers are able to modify views (e.g., FreeMarker templates) at runtime after which you'd need to clear the cache for the specified view.
- Parameters:
viewName
- the view name for which the cached view object (if any) needs to be removedlocale
- the locale for which the view object should be removed
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clearCache
public void clearCache()Clear the entire view cache, removing all cached view objects. Subsequent resolve calls will lead to recreation of demanded view objects. -
createView
Create the actual View object.The default implementation delegates to
loadView(java.lang.String, java.util.Locale)
. This can be overridden to resolve certain view names in a special fashion, before delegating to the actualloadView
implementation provided by the subclass.- Parameters:
viewName
- the name of the view to retrievelocale
- the Locale to retrieve the view for- Returns:
- the View instance, or
null
if not found (optional, to allow for ViewResolver chaining) - Throws:
Exception
- if the view couldn't be resolved- See Also:
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loadView
Subclasses must implement this method, building a View object for the specified view. The returned View objects will be cached by this ViewResolver base class.Subclasses are not forced to support internationalization: A subclass that does not may simply ignore the locale parameter.
- Parameters:
viewName
- the name of the view to retrievelocale
- the Locale to retrieve the view for- Returns:
- the View instance, or
null
if not found (optional, to allow for ViewResolver chaining) - Throws:
Exception
- if the view couldn't be resolved- See Also:
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