dekoh.portal.syndication.aggregator.core
Class AggregatorImpl

java.lang.Object
  dekoh.portal.syndication.aggregator.core.AggregatorImpl

All Implemented Interfaces:

Aggregator

public class AggregatorImpl
extends Object
implements Aggregator

AggregatorImpl is the default feed aggregator implementation provided. Instances of this can be created by AggregatorFactory . All instances of this class will share a single timer thread. Aggregator timer task will be non blocking and will return once it has submited the aggragation job to an executor pool.

Since:

Oct 25, 2007

Field Summary

protected File	cacheDir
protected FeedRetriever	feedRetriever

Method Summary

void	addAggregatedItemTransformer(AggregatedItemTransformer[] transformers)
void	destroy() Stops the scheduler.
List	getAggregatedItemTransformers()
File	getAggregatedRSSFeedXml() After aggregation the aggregated feed is stored in a file named "aggregate-subscriptionListId.xml", if it is an inMemorySubscriptionList, aggregated file will be stored as "aggregate-aggregatorId.xml"
FeedRetriever	getFeedRetriever()
String	getId()
File	getItemRSSFeedXml(String subscriptionItemId) Each downloaded subscription item feed is stored in a file named "aggregate-subscriptionListId-subscriptionItemId.xml"
long	getLastAggregatedTime()
long	getLastModifiedTime()
int	getMaxItemsToAggregate()
long	getSchedulerFrequency()
SubscriptionItemFetcher	getSubscriptionItemFetcher()
SubscriptionList	getSubscriptionList()
boolean	isScheduled()
void	scheduleAggregation() Triggers a periodic aggregation that becomes enabled now, and subsequently repeats itself after a frequency.Implementatin can chose to have a defualt frequency or take in the the constructor Generally this will be a one time call, However it can be used to start aggregation "now", to check for latest feeds
void	scheduleAggregation(long frequencyInMilliSec) It will stop the aggregation if it is running and reschedule the aggregation with the specified frequecy
void	setMaxItemsToAggregate(int maxItemsToAggregate)
void	stopScheduler() Stops the scheduling of aggregator.

Methods inherited from class java.lang.Object

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

Field Detail

feedRetriever

protected FeedRetriever feedRetriever

cacheDir

protected File cacheDir

Method Detail

getSubscriptionItemFetcher

public SubscriptionItemFetcher getSubscriptionItemFetcher()

getFeedRetriever

public FeedRetriever getFeedRetriever()

getId

public final String getId()

Specified by:

getId in interface Aggregator

Returns:

An id which can be used to find this aggregator instance

getAggregatedItemTransformers

public List getAggregatedItemTransformers()

Specified by:

getAggregatedItemTransformers in interface Aggregator

Returns:

the transformer which will be given a callback before a new feed entry is made part of aggregated item

getMaxItemsToAggregate

public int getMaxItemsToAggregate()

Specified by:

getMaxItemsToAggregate in interface Aggregator

Returns:

maximum feed entries that will be part of aggregation

getSubscriptionList

public SubscriptionList getSubscriptionList()

Specified by:

getSubscriptionList in interface Aggregator

Returns:

SubscriptionList which is scheduked for aggregation

getLastAggregatedTime

public long getLastAggregatedTime()

Specified by:

getLastAggregatedTime in interface Aggregator

Returns:

time in milliseconds when the aggragation las happened

getLastModifiedTime

public long getLastModifiedTime()

Specified by:

getLastModifiedTime in interface Aggregator

Returns:

time in millisecond when the aggregated feed was las modified

setMaxItemsToAggregate

public void setMaxItemsToAggregate(int maxItemsToAggregate)

Specified by:

setMaxItemsToAggregate in interface Aggregator

Parameters:

maxItemsToAggregate - maximum items that will be aggregated byu this aggregater. Aggregators may choose a policy to remove items from the aggregated feed if the total no of aggregated items exceeds this limit.

getAggregatedRSSFeedXml

public File getAggregatedRSSFeedXml()

After aggregation the aggregated feed is stored in a file named "aggregate-subscriptionListId.xml", if it is an inMemorySubscriptionList, aggregated file will be stored as "aggregate-aggregatorId.xml"

Specified by:

getAggregatedRSSFeedXml in interface Aggregator

Returns:

the file representing aggregated feed

scheduleAggregation

public void scheduleAggregation()

Description copied from interface: Aggregator

Triggers a periodic aggregation that becomes enabled now, and subsequently repeats itself after a frequency.Implementatin can chose to have a defualt frequency or take in the the constructor

Generally this will be a one time call, However it can be used to start aggregation "now", to check for latest feeds

Specified by:

scheduleAggregation in interface Aggregator

See Also:

Aggregator.scheduleAggregation(long)

scheduleAggregation

public void scheduleAggregation(long frequencyInMilliSec)

It will stop the aggregation if it is running and reschedule the aggregation with the specified frequecy

Specified by:

scheduleAggregation in interface Aggregator

Parameters:

frequencyInMilliSec - frequency with which aggregation will happen

stopScheduler

public void stopScheduler()

Description copied from interface: Aggregator

Stops the scheduling of aggregator. The subscription items in the list will not be downloaded and aggregated any more

Specified by:

stopScheduler in interface Aggregator

See Also:

Aggregator.scheduleAggregation(long)

isScheduled

public boolean isScheduled()

Specified by:

isScheduled in interface Aggregator

Returns:

true if the aggregator is scheduled
false if aggregator was never scheduled or is stopped

getSchedulerFrequency

public long getSchedulerFrequency()

Specified by:

getSchedulerFrequency in interface Aggregator

Returns:

frequency in milliseconds at which the aggregator is scheduled, value of zero indicate that the aggregator was never scheduled or is stopeed.

destroy

public void destroy()

Stops the scheduler. If it is aggregating an InMemorySubscriptionList deletes all the downloaded feeds files and the aggregated file created during the aggregation process

Specified by:

destroy in interface Aggregator

addAggregatedItemTransformer

public void addAggregatedItemTransformer(AggregatedItemTransformer[] transformers)

Specified by:

addAggregatedItemTransformer in interface Aggregator

Parameters:

transformers - which will be given a callback before a new feed entry is made part of aggregated item

getItemRSSFeedXml

public File getItemRSSFeedXml(String subscriptionItemId)

Each downloaded subscription item feed is stored in a file named "aggregate-subscriptionListId-subscriptionItemId.xml"

Specified by:

getItemRSSFeedXml in interface Aggregator

Parameters:

subscriptionItemId - id of a subscription item in the list

Returns:

the downloaded feed for the subscription item