org.springframework.web.servlet.view
Class AbstractCachingViewResolver

java.lang.Object
  org.springframework.context.support.ApplicationObjectSupport
      org.springframework.web.context.support.WebApplicationObjectSupport
          org.springframework.web.servlet.view.AbstractCachingViewResolver

All Implemented Interfaces:

ApplicationContextAware, ViewResolver

Direct Known Subclasses:

ResourceBundleViewResolver, UrlBasedViewResolver, XmlViewResolver

public abstract class AbstractCachingViewResolver

extends WebApplicationObjectSupport

implements ViewResolver

Convenient superclass for view resolvers. Caches views once resolved: This means that view resolution won't be a performance problem, no matter how costly initial view retrieval is.

View retrieval is deferred to subclasses via the loadView template method.

Author:

Rod Johnson, Juergen Hoeller

See Also:

loadView(java.lang.String, java.util.Locale)

Field Summary

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

logger

Constructor Summary

AbstractCachingViewResolver()

Method Summary

protected java.lang.String	getCacheKey(java.lang.String viewName, java.util.Locale locale) Return the cache key for the given viewName and the given locale.
boolean	isCache() Return if caching is enabled.
protected abstract View	loadView(java.lang.String viewName, java.util.Locale locale) Subclasses must implement this method.
View	resolveViewName(java.lang.String viewName, java.util.Locale locale) Resolve the given view by name.
void	setCache(boolean cache) Enable respectively disable caching.

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

getServletContext, getTempDir, getWebApplicationContext, requiredContextClass

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

getApplicationContext, getMessageSourceAccessor, initApplicationContext, setApplicationContext

Methods inherited from class java.lang.Object

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

Constructor Detail

AbstractCachingViewResolver

public AbstractCachingViewResolver()

Method Detail

setCache

public void setCache(boolean cache)

Enable respectively disable caching. Disable this only for debugging and development. Default is for caching to be enabled.

Warning: Disabling caching can severely impact performance. Tests indicate that turning caching off reduces performance by at least 20%. Increased object churn probably eventually makes the problem even worse.

isCache

public boolean isCache()

Return if caching is enabled.

resolveViewName

public View resolveViewName(java.lang.String viewName,
                            java.util.Locale locale)
                     throws java.lang.Exception

Description copied from interface: ViewResolver

Resolve the given view by name.

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.

Throws:

java.lang.Exception - if the view cannot be resolved

getCacheKey

protected java.lang.String getCacheKey(java.lang.String viewName,
                                       java.util.Locale locale)

Return the cache key for the given viewName and the given locale. Needs to regard the locale in general, as a different locale can lead to a different view! Can be overridden in subclasses.

loadView

protected abstract View loadView(java.lang.String viewName,
                                 java.util.Locale locale)
                          throws java.lang.Exception

Subclasses must implement this method. There need be no concern for efficiency, as this class will cache views. Not all subclasses may support internationalization: A subclass that doesn't can simply ignore the locale parameter.

Parameters:

viewName - the name of the view to retrieve

locale - the Locale to retrieve the view for

Returns:

the View instance

Throws:

java.lang.Exception - if the view couldn't be resolved