com.sun.appserv.web.cache
Class DefaultCacheHelper

java.lang.Object
  com.sun.appserv.web.cache.DefaultCacheHelper

All Implemented Interfaces:

CacheHelper

public class DefaultCacheHelper
extends Object
implements CacheHelper

DefaultCacheHelper interface is the built-in implementation of the CacheHelper interface to aide in: a) the key generation b) whether to cache the response. There is one CacheHelper instance per web application.

Field Summary

static String	ATTR_CACHING_FILTER_NAME
static String	PROP_KEY_GENERATOR_ATTR_NAME

Fields inherited from interface com.sun.appserv.web.cache.CacheHelper

ATTR_CACHE_MAPPED_SERVLET_NAME, ATTR_CACHE_MAPPED_URL_PATTERN, TIMEOUT_VALUE_NOT_SET

Constructor Summary

DefaultCacheHelper()

Method Summary

void	destroy() Stop this Context component.
String	getCacheKey(HttpServletRequest request) getCacheKey: generate the key to be used to cache this request
int	getTimeout(HttpServletRequest request) get timeout for the cacheable data in this request
void	init(ServletContext context, Map props) initialize this helper
boolean	isCacheable(HttpServletRequest request) isCacheable: is the response to given request cachebale?
boolean	isRefreshNeeded(HttpServletRequest request) isRefreshNeeded: is the response to given request be refreshed?
void	setCacheManager(CacheManager manager) set the CacheManager for this application

Methods inherited from class java.lang.Object

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

Field Detail

ATTR_CACHING_FILTER_NAME

public static final String ATTR_CACHING_FILTER_NAME

See Also:

Constant Field Values

PROP_KEY_GENERATOR_ATTR_NAME

public static final String PROP_KEY_GENERATOR_ATTR_NAME

See Also:

Constant Field Values

Constructor Detail

DefaultCacheHelper

public DefaultCacheHelper()

Method Detail

setCacheManager

public void setCacheManager(CacheManager manager)

set the CacheManager for this application

Parameters:

manager - associated with this application

init

public void init(ServletContext context,
                 Map props)

initialize this helper

Specified by:

init in interface CacheHelper

Parameters:

context - the web application context this helper belongs to

props - helper properties

getCacheKey

public String getCacheKey(HttpServletRequest request)

getCacheKey: generate the key to be used to cache this request

Specified by:

getCacheKey in interface CacheHelper

Parameters:

request - incoming HttpServletRequest

Returns:

key string used to access the cache entry. Key is composed of: servletPath + a concatenation of the field values in the request; all key field names must be found in the appropriate scope.

isCacheable

public boolean isCacheable(HttpServletRequest request)

isCacheable: is the response to given request cachebale?

Specified by:

isCacheable in interface CacheHelper

Parameters:

request - incoming HttpServletRequest object

Returns:

true if the response could be cached. or return false if the results of this request must not be cached. Applies pre-configured cacheability constraints in the cache-mapping; all constraints must pass for this to be cacheable.

isRefreshNeeded

public boolean isRefreshNeeded(HttpServletRequest request)

isRefreshNeeded: is the response to given request be refreshed?

Specified by:

isRefreshNeeded in interface CacheHelper

Parameters:

request - incoming HttpServletRequest object

Returns:

true if the response needs to be refreshed. or return false if the results of this request don't need to be refreshed. XXX: 04/16/02 right now there is no configurability for this in ias-web.xml; should add a refresh-field element there:

getTimeout

public int getTimeout(HttpServletRequest request)

get timeout for the cacheable data in this request

Specified by:

getTimeout in interface CacheHelper

Parameters:

request - incoming HttpServletRequest object

Returns:

either the statically specified value or from the request fields. If not specified, get the timeout defined for the cache element.

destroy

public void destroy()
             throws Exception

Stop this Context component.

Specified by:

destroy in interface CacheHelper

Throws:

Exception - if a shutdown error occurs