org.w3c.www.protocol.http.cache.push
Class PushCacheFilter

java.lang.Object
  org.w3c.www.protocol.http.cache.CacheFilter
      org.w3c.www.protocol.http.cache.push.PushCacheFilter

All Implemented Interfaces:

PropertyMonitoring, PropRequestFilter, RequestFilter

public class PushCacheFilter
extends CacheFilter

PushCacheFilter Based heavily on (much code stolen from) CacheFilter The important differences are in the initialization where the PushCacheListener is started, and in ingoingFilter where if the requested resource is present in the cache and is a PUSH resource, then the resource is returned immediately without checking for expiry etc. This allows us to insert pages from "virtual" web sites such as http://www.push.data/sensor1.html

Field Summary

static int	DEFAULT_PORT_NUM Default port number to use if property value is not supplied value is 9876
static java.lang.String	PORT_NUM_P Property name used to acquire port number for PushCacheListener value is "org.w3c.www.protocol.http.cache.push.portnumber";

Fields inherited from class org.w3c.www.protocol.http.cache.CacheFilter

CACHE_CONNECTED_P, CACHE_SIZE_P, connected, debug, DEBUG_P, directory, precache, props, serializer, SERIALIZER_P, shared, SHARED_P, size, STATE_NOCACHE, STATE_ORIGREQ, STATE_REVALIDATION, STATE_WARNINGS, store, sweeper, SWEEPER_P, uritable, validator, VALIDATOR_P, WARN_DISCONNECTED, WARN_HEURISTIC, WARN_STALE

Constructor Summary

PushCacheFilter()

Method Summary

boolean	canUseCache(Request req) check if we can use the cache or not for this request It marks the request as being not cachable if false.
org.w3c.www.protocol.http.cache.push.PushCacheStore	getPushCacheStore() Access to PushCacheStore
Reply	ingoingFilter(Request request) The request pre-processing hook.
void	initialize(HttpManager manager) Almost identical to CacheFilter.initialize, but creates a PushCacheStore instead of a CacheStore and additionaly starts the PushCacheListener

Methods inherited from class org.w3c.www.protocol.http.cache.CacheFilter

addWarning, canCache, canStore, cleanUpload, exceptionFilter, getSerializer, getStore, getSweeper, getValidator, isConnected, isShared, outgoingFilter, propertyChanged, pushDocument, setRequestRevalidation, setWarnings, sync, trace

Methods inherited from class java.lang.Object

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

Field Detail

PORT_NUM_P

public static final java.lang.String PORT_NUM_P

Property name used to acquire port number for PushCacheListener value is "org.w3c.www.protocol.http.cache.push.portnumber";

See Also:

Constant Field Values

DEFAULT_PORT_NUM

public static final int DEFAULT_PORT_NUM

Default port number to use if property value is not supplied value is 9876

See Also:

Constant Field Values

Constructor Detail

PushCacheFilter

public PushCacheFilter()

Method Detail

getPushCacheStore

public org.w3c.www.protocol.http.cache.push.PushCacheStore getPushCacheStore()

Access to PushCacheStore

canUseCache

public boolean canUseCache(Request req)

check if we can use the cache or not for this request It marks the request as being not cachable if false.

Overrides:

canUseCache in class CacheFilter

Parameters:

a - request, the incoming client-side request

Returns:

a boolean, true if we can use the cache

ingoingFilter

public Reply ingoingFilter(Request request)
                    throws HttpException

The request pre-processing hook. Before each request is launched, all filters will be called back through this method. They will generally set up additional request header fields to enhance the request.

Specified by:

ingoingFilter in interface RequestFilter

Overrides:

ingoingFilter in class CacheFilter

Parameters:

request - The request that is about to be launched.

Returns:

An instance of Reply if the filter could handle the request, or null if processing should continue normally.

Throws:

HttpException - If the filter is supposed to fulfill the request, but some error happened during that processing.

initialize

public void initialize(HttpManager manager)
                throws PropRequestFilterException

Almost identical to CacheFilter.initialize, but creates a PushCacheStore instead of a CacheStore and additionaly starts the PushCacheListener

Specified by:

initialize in interface PropRequestFilter

Overrides:

initialize in class CacheFilter

Parameters:

manager - The HttpManager initializing the filter.

Throws:

PropRequestFilterException - If the filter couldn't be initialized properly.