Package org.apache.wicket.markup

Class MarkupCache

java.lang.Object

org.apache.wicket.markup.MarkupCache

All Implemented Interfaces:

IMarkupCache

public class MarkupCache
extends Object
implements IMarkupCache

This is Wicket's default IMarkupCache implementation. It will load the markup and cache it for fast retrieval.

If the application is in development mode and a markup file changes, it'll automatically be removed from the cache and reloaded when needed.

MarkupCache is registered with MarkupFactory which in turn is registered with MarkupSettings and thus can be replaced with a sub-classed version.

Author:

Jonathan Locke, Juergen Donnerstag

See Also:

MarkupSettings, MarkupFactory

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	MarkupCache.DefaultCacheImplementation<K,V>
static interface	MarkupCache.ICache<K,V>	MarkupCache allows you to implement you own cache implementation.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	MarkupCache()	Constructor.

Method Summary

Modifier and Type	Method	Description
void	clear()	Clear markup cache and force reload of all markup data
static IMarkupCache	get()	A convenient helper to get the markup cache registered with the application.
Markup	getMarkup(MarkupContainer container, Class<?> clazz, boolean enforceReload)	Gets any (immutable) markup resource for the container or any of its parent classes (markup inheritance)
MarkupCache.ICache<String,Markup>	getMarkupCache()	Get a unmodifiable map which contains the cached data.
IMarkupCacheKeyProvider	getMarkupCacheKeyProvider(MarkupContainer container)	Get the markup cache key provider to be used
protected Markup	getMarkupFromCache(String cacheKey, MarkupContainer container)	Wicket's default implementation just uses the cacheKey to retrieve the markup from the cache.
protected <K,V> MarkupCache.ICache<K,V>	newCacheImplementation()	Allows you to change the map implementation which will hold the cache data.
protected Markup	onMarkupNotFound(String cacheKey, MarkupContainer container, Markup markup)	Will be called if the markup was not in the cache yet and could not be found either.
protected Markup	putIntoCache(String locationString, MarkupContainer container, Markup markup)	Put the markup into the cache if cacheKey is not null and the cache does not yet contain the cacheKey.
IMarkupFragment	removeMarkup(String cacheKey)	Note that this method will be called from a "cleanup" thread which might not have a thread local application.
void	shutdown()	Will be called by the application while shutting down.
int	size()

Methods inherited from class java.lang.Object

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

Constructor Detail

MarkupCache

protected MarkupCache()

Constructor.

Method Detail

get

public static IMarkupCache get()

A convenient helper to get the markup cache registered with the application.

Returns:

The markup cache registered with the Application

See Also:

Application.getMarkupSettings(), MarkupFactory.getMarkupCache()

clear

public void clear()

Description copied from interface: IMarkupCache

Clear markup cache and force reload of all markup data

Specified by:

clear in interface IMarkupCache

shutdown

public void shutdown()

Description copied from interface: IMarkupCache

Will be called by the application while shutting down. It allows the markup cache to cleanup if necessary.

Specified by:

shutdown in interface IMarkupCache

removeMarkup

public final IMarkupFragment removeMarkup(String cacheKey)

Note that this method will be called from a "cleanup" thread which might not have a thread local application.

Specified by:

removeMarkup in interface IMarkupCache

Returns:

The markup removed from the cache. Null, if nothing was found.

See Also:

MarkupResourceStream.getCacheKey()

size

public final int size()

Specified by:

size in interface IMarkupCache

Returns:

the number of elements currently in the cache.

getMarkupCache

public final MarkupCache.ICache<String,Markup> getMarkupCache()

Get a unmodifiable map which contains the cached data. The map key is of type String and the value is of type Markup.

May be used to debug or iterate the cache content.

Returns:

cache implementation

getMarkup

public final Markup getMarkup(MarkupContainer container,
                              Class<?> clazz,
                              boolean enforceReload)

Description copied from interface: IMarkupCache

Gets any (immutable) markup resource for the container or any of its parent classes (markup inheritance)

Specified by:

getMarkup in interface IMarkupCache

Parameters:

container - The original requesting markup container

clazz - The class to get the associated markup for. If null, the container's class is used, but it can be a parent class of the container as well (markup inheritance)

enforceReload - The cache will be ignored and all, including inherited markup files, will be reloaded. Whatever is in the cache, it will be ignored

Returns:

Markup resource

onMarkupNotFound

protected Markup onMarkupNotFound(String cacheKey,
                                  MarkupContainer container,
                                  Markup markup)

Will be called if the markup was not in the cache yet and could not be found either.

Subclasses may change the default implementation. E.g. they might choose not to update the cache to enforce reloading of any markup not found. This might be useful in very dynamic environments. Additionally a non-caching IResourceStreamLocator should be used.

Parameters:

cacheKey -

container -

markup - Markup.NO_MARKUP

Returns:

Same as parameter "markup"

See Also:

ResourceSettings.setResourceStreamLocator(org.apache.wicket.core.util.resource.locator.IResourceStreamLocator)

putIntoCache

protected Markup putIntoCache(String locationString,
                              MarkupContainer container,
                              Markup markup)

Put the markup into the cache if cacheKey is not null and the cache does not yet contain the cacheKey. Return the markup stored in the cache if cacheKey is present already. More sophisticated implementations may call a container method to e.g. cache it per container instance.

Parameters:

locationString - If null then ignore the cache

container - The container this markup is for.

markup -

Returns:

markup The markup provided, except if the cacheKey already existed in the cache, then the markup from the cache is provided.

getMarkupFromCache

protected Markup getMarkupFromCache(String cacheKey,
                                    MarkupContainer container)

Wicket's default implementation just uses the cacheKey to retrieve the markup from the cache. More sophisticated implementations may call a container method to e.g. ignore the cached markup under certain situations.

Parameters:

cacheKey - If null, than the cache will be ignored

container -

Returns:

null, if not found or to enforce reloading the markup

getMarkupCacheKeyProvider

public IMarkupCacheKeyProvider getMarkupCacheKeyProvider(MarkupContainer container)

Get the markup cache key provider to be used

Parameters:

container - The MarkupContainer requesting the markup resource stream

Returns:

IMarkupResourceStreamProvider

newCacheImplementation

protected <K,V> MarkupCache.ICache<K,V> newCacheImplementation()

Allows you to change the map implementation which will hold the cache data. By default it is a ConcurrentHashMap() in order to allow multiple thread to access the data in a secure way.

Type Parameters:

K -

V -

Returns:

new instance of cache implementation