org.apache.wiki.providers
Class CachingProvider

java.lang.Object
  org.apache.wiki.providers.CachingProvider

All Implemented Interfaces:

WikiPageProvider, WikiProvider

public class CachingProvider
extends Object
implements WikiPageProvider

Provides a caching page provider. This class rests on top of a real provider class and provides a cache to speed things up. Only if the cache copy of the page text has expired, we fetch it from the provider.

This class does not detect if someone has modified the page externally, not through JSPWiki routines.

Heavily based on ideas by Chris Brooking.

Since 2.10 uses the Ehcache library.

Since:

1.6.4

Field Summary

static String	CACHE_NAME Name of the regular page cache.
static int	DEFAULT_CACHECAPACITY The capacity of the caches, if you want something else, tweak ehcache.xml.
static String	HISTORYCACHE_NAME Name of the page history cache.
static String	TEXTCACHE_NAME Name of the page text cache.

Fields inherited from interface org.apache.wiki.WikiProvider

LATEST_VERSION

Constructor Summary

CachingProvider()

Method Summary

void	deletePage(String pageName) Removes an entire page from the repository.
void	deleteVersion(String pageName, int version) Removes a specific version from the repository.
Collection	findPages(QueryItem[] query) Finds pages based on the query.
Collection	getAllChangedSince(Date date) Gets a list of recent changes.
Collection	getAllPages() Returns all pages.
int	getPageCount() Gets the number of pages.
WikiPage	getPageInfo(String pageName, int version) Returns info about the page.
String	getPageText(String pageName, int version) Gets a specific version out of the repository.
String	getProviderInfo() Gets the provider class name, and cache statistics (misscount and hitcount of page cache and history cache).
WikiPageProvider	getRealProvider() Returns the actual used provider.
List	getVersionHistory(String pageName) Returns version history.
void	initialize(WikiEngine engine, Properties properties) Initializes the page provider.
void	movePage(String from, String to) Move a page
boolean	pageExists(String pageName) Return true, if page exists.
boolean	pageExists(String pageName, int version) Return true, if page with a particular version exists.
void	putPageText(WikiPage page, String text) Attempts to save the page text for page "page".

Methods inherited from class java.lang.Object

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

Field Detail

CACHE_NAME

public static final String CACHE_NAME

Name of the regular page cache.

See Also:

Constant Field Values

TEXTCACHE_NAME

public static final String TEXTCACHE_NAME

Name of the page text cache.

See Also:

Constant Field Values

HISTORYCACHE_NAME

public static final String HISTORYCACHE_NAME

Name of the page history cache.

See Also:

Constant Field Values

DEFAULT_CACHECAPACITY

public static final int DEFAULT_CACHECAPACITY

The capacity of the caches, if you want something else, tweak ehcache.xml.

See Also:

Constant Field Values

Constructor Detail

CachingProvider

public CachingProvider()

Method Detail

initialize

public void initialize(WikiEngine engine,
                       Properties properties)
                throws NoRequiredPropertyException,
                       IOException

Initializes the page provider.

Specified by:

initialize in interface WikiProvider

Parameters:

engine - WikiEngine to own this provider

properties - A set of properties used to initialize this provider

Throws:

NoRequiredPropertyException - If the provider needs a property which is not found in the property set

IOException - If there is an IO problem

pageExists

public boolean pageExists(String pageName,
                          int version)

Return true, if page with a particular version exists.

Specified by:

pageExists in interface WikiPageProvider

Parameters:

pageName - The page name to check for

version - The version to check

Returns:

True, if page exists; false otherwise.

pageExists

public boolean pageExists(String pageName)

Return true, if page exists.

Specified by:

pageExists in interface WikiPageProvider

Parameters:

pageName - The page name.

Returns:

true, if the page exists; false otherwise.

getPageText

public String getPageText(String pageName,
                          int version)
                   throws ProviderException

Gets a specific version out of the repository.

Specified by:

getPageText in interface WikiPageProvider

Parameters:

pageName - Name of the page to fetch.

version - Version of the page to fetch.

Returns:

The content of the page, or null, if the page does not exist.

Throws:

ProviderException - If something goes wrong.

putPageText

public void putPageText(WikiPage page,
                        String text)
                 throws ProviderException

Attempts to save the page text for page "page". Note that the provider creates a new version regardless of what the version parameter of the WikiPage is.

Specified by:

putPageText in interface WikiPageProvider

Parameters:

page - The WikiPage to save

text - The text to save.

Throws:

ProviderException - If something goes wrong.

getAllPages

public Collection getAllPages()
                       throws ProviderException

Returns all pages. Each element in the returned Collection should be a WikiPage.

Specified by:

getAllPages in interface WikiPageProvider

Returns:

A collection of WikiPages

Throws:

ProviderException - If something goes wrong.

getAllChangedSince

public Collection getAllChangedSince(Date date)

Gets a list of recent changes.

Specified by:

getAllChangedSince in interface WikiPageProvider

Parameters:

date - The date to check from

Returns:

A Collection of WikiPages

getPageCount

public int getPageCount()
                 throws ProviderException

Gets the number of pages.

Specified by:

getPageCount in interface WikiPageProvider

Returns:

The number of pages in the repository

Throws:

ProviderException - If something goes wrong

findPages

public Collection findPages(QueryItem[] query)

Finds pages based on the query. Only applicable to providers which implement the FastSearch interface. Otherwise JSPWiki will use its internal cache.

This method should really be a part of the FastSearch IF.

Specified by:

findPages in interface WikiPageProvider

Parameters:

query - An array of QueryItems to match

Returns:

A Collection of WikiPages.

getPageInfo

public WikiPage getPageInfo(String pageName,
                            int version)
                     throws ProviderException

Returns info about the page.

Specified by:

getPageInfo in interface WikiPageProvider

Parameters:

pageName - The page name

version - The version number

Returns:

A filled WikiPage.

Throws:

ProviderException - If something goes wrong.

getVersionHistory

public List getVersionHistory(String pageName)
                       throws ProviderException

Returns version history. Each element should be a WikiPage.

Specified by:

getVersionHistory in interface WikiPageProvider

Parameters:

pageName - The name of the page to get the history from.

Returns:

A collection of WikiPages.

Throws:

ProviderException - If something goes wrong.

getProviderInfo

public String getProviderInfo()

Gets the provider class name, and cache statistics (misscount and hitcount of page cache and history cache).

Specified by:

getProviderInfo in interface WikiProvider

Returns:

A plain string with all the above mentioned values.

deleteVersion

public void deleteVersion(String pageName,
                          int version)
                   throws ProviderException

Removes a specific version from the repository. The implementations should really do no more security checks, since that is the domain of the PageManager. Just delete it as efficiently as you can.

Specified by:

deleteVersion in interface WikiPageProvider

Parameters:

pageName - Name of the page to be removed.

version - Version of the page to be removed. May be LATEST_VERSION.

Throws:

ProviderException - If the page cannot be removed for some reason.

deletePage

public void deletePage(String pageName)
                throws ProviderException

Removes an entire page from the repository. The implementations should really do no more security checks, since that is the domain of the PageManager. Just delete it as efficiently as you can. You should also delete any auxiliary files that belong to this page, IF they were created by this provider.

The reason why this is named differently from deleteVersion() (logically, this method should be an overloaded version) is that I want to be absolutely sure I don't accidentally use the wrong method. With overloading something like that happens sometimes...

Specified by:

deletePage in interface WikiPageProvider

Parameters:

pageName - Name of the page to be removed completely.

Throws:

ProviderException - If the page could not be removed for some reason.

movePage

public void movePage(String from,
                     String to)
              throws ProviderException

Move a page

Specified by:

movePage in interface WikiPageProvider

Parameters:

from - Name of the page to move.

to - New name of the page.

Throws:

ProviderException - If the page could not be moved for some reason.

getRealProvider

public WikiPageProvider getRealProvider()

Returns the actual used provider.

Returns:

The real provider.

Since:

2.0