Package org.entur.jwt.client

Class PreemptiveCachedAccessTokenProvider

java.lang.Object

org.entur.jwt.client.BaseAccessTokenProvider

org.entur.jwt.client.AbstractCachedAccessTokenProvider

org.entur.jwt.client.DefaultCachedAccessTokenProvider

org.entur.jwt.client.PreemptiveCachedAccessTokenProvider

All Implemented Interfaces:

Closeable, AutoCloseable, AccessTokenHealthProvider, AccessTokenProvider

public class PreemptiveCachedAccessTokenProvider
extends DefaultCachedAccessTokenProvider

Caching AccessTokenProvider which preemptively attempts to update the cache in the background. The preemptive updates themselves run on a separate, dedicated thread. Updates are is not continuously scheduled, but (lazily) triggered by incoming requests for access-tokens.

This class is intended for uninterrupted operation in high-load scenarios, as it will avoid a (potentially) large number of threads blocking when the cache expires (and must be refreshed).

Nested Class Summary

Nested classes/interfaces inherited from class org.entur.jwt.client.AbstractCachedAccessTokenProvider

AbstractCachedAccessTokenProvider.AccessTokenCacheItem

Field Summary

Fields

Modifier and Type	Field	Description
protected static final org.slf4j.Logger	logger

Fields inherited from class org.entur.jwt.client.DefaultCachedAccessTokenProvider

lock, minimumTimeToLive, refreshTimeout

Fields inherited from class org.entur.jwt.client.AbstractCachedAccessTokenProvider

cache

Fields inherited from class org.entur.jwt.client.BaseAccessTokenProvider

provider

Constructor Summary

Constructors

Constructor	Description
PreemptiveCachedAccessTokenProvider(AccessTokenProvider provider, long minimumTimeToLive, long refreshTimeout, long preemptiveRefresh, int refreshConstraintInPercent, boolean eager)	Construct new instance.
PreemptiveCachedAccessTokenProvider(AccessTokenProvider provider, long minimumTimeToLive, long refreshTimeout, long preemptiveRefresh, int refreshConstraintInPercent, boolean eager, ExecutorService executorService, boolean shutdownExecutorOnClose)	Construct new instance, use a custom executor service.
PreemptiveCachedAccessTokenProvider(AccessTokenProvider provider, long minimumTimeToLiveUnits, TimeUnit minimumTimeToLiveUnit, long refreshTimeoutUnits, TimeUnit refreshTimeoutUnit, long preemptiveTimeoutUnits, TimeUnit preemptiveTimeoutUnit, int refreshConstraintInPercent, boolean eager)	Construct new instance.

Method Summary

Modifier and Type	Method	Description
void	close()
protected AbstractCachedAccessTokenProvider.AccessTokenCacheItem	createCacheItem(long time, AccessToken accessToken)
AccessToken	getAccessToken(long time, boolean forceUpdate)
protected ScheduledFuture<?>	getEagerScheduledFuture()
ExecutorService	getExecutorService()	Return the executor service which services the background refresh.
protected String	getTime(long update)
protected AbstractCachedAccessTokenProvider.AccessTokenCacheItem	loadAccessTokenFromProvider(long time)
protected void	preemptiveRefresh(long time, AbstractCachedAccessTokenProvider.AccessTokenCacheItem cache, boolean forceRefresh)	Preemptive update.
protected void	schedulePreemptiveRefresh(long time, AbstractCachedAccessTokenProvider.AccessTokenCacheItem cache)

Methods inherited from class org.entur.jwt.client.DefaultCachedAccessTokenProvider

getAccessTokenBlocking, getCachedAccessToken, getMinimumTimeToLive, getRefreshTimeout

Methods inherited from class org.entur.jwt.client.AbstractCachedAccessTokenProvider

getAccessToken, getCache, getCachedAccessToken

Methods inherited from class org.entur.jwt.client.BaseAccessTokenProvider

getHealth, getProvider, supportsHealth

Methods inherited from class java.lang.Object

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

Field Details

logger

protected static final org.slf4j.Logger logger

Constructor Details

PreemptiveCachedAccessTokenProvider

public PreemptiveCachedAccessTokenProvider(AccessTokenProvider provider,
 long minimumTimeToLiveUnits,
 TimeUnit minimumTimeToLiveUnit,
 long refreshTimeoutUnits,
 TimeUnit refreshTimeoutUnit,
 long preemptiveTimeoutUnits,
 TimeUnit preemptiveTimeoutUnit,
 int refreshConstraintInPercent,
 boolean eager)

Construct new instance.

Parameters:

provider - Access-token provider

minimumTimeToLiveUnits - minimum time to live (left when returned by AbstractCachedAccessTokenProvider.getAccessToken(boolean)).

minimumTimeToLiveUnit - minimum time to live unit

refreshTimeoutUnits - cache refresh timeout

refreshTimeoutUnit - cache refresh timeout unit

preemptiveTimeoutUnits - preemptive timeout. This parameter is relative to time to live, i.e. "15 seconds before timeout, refresh time cached value".

preemptiveTimeoutUnit - preemptive timeout unit

refreshConstraintInPercent - constraint in percent, of a token's lifetime, before any preemptive refresh happens

eager - preemptive refresh even if no traffic (schedule update)

PreemptiveCachedAccessTokenProvider

public PreemptiveCachedAccessTokenProvider(AccessTokenProvider provider,
 long minimumTimeToLive,
 long refreshTimeout,
 long preemptiveRefresh,
 int refreshConstraintInPercent,
 boolean eager)

Construct new instance.

Parameters:

provider - Access-token provider

minimumTimeToLive - minimum time to live (left when returned by AbstractCachedAccessTokenProvider.getAccessToken(boolean)).

refreshTimeout - cache refresh timeout unit (in milliseconds)

preemptiveRefresh - preemptive refresh limit (in milliseconds). This parameter is relative to time to live, i.e. "15000 milliseconds before token is invalid, refresh cached value".

refreshConstraintInPercent - constraint in percent, of a token's lifetime, before any preemptive refresh happens

eager - preemptive refresh even if no traffic (schedule update)

PreemptiveCachedAccessTokenProvider

public PreemptiveCachedAccessTokenProvider(AccessTokenProvider provider,
 long minimumTimeToLive,
 long refreshTimeout,
 long preemptiveRefresh,
 int refreshConstraintInPercent,
 boolean eager,
 ExecutorService executorService,
 boolean shutdownExecutorOnClose)

Construct new instance, use a custom executor service.

Parameters:

provider - Access-token provider

minimumTimeToLive - minimum time to live (left when returned by AbstractCachedAccessTokenProvider.getAccessToken(boolean)).

refreshTimeout - cache refresh timeout unit (in milliseconds)

preemptiveRefresh - preemptive timeout (in milliseconds). This parameter is relative to time to live, i.e. "15000 milliseconds before timeout, refresh time cached value".

refreshConstraintInPercent - constraint in percent, of a token's lifetime, before any preemptive refresh happens

eager - preemptive refresh even if no traffic (schedule update)

executorService - executor service

shutdownExecutorOnClose - Whether to shutdown the executor service on calls to close(..).

Method Details

getAccessToken

public AccessToken getAccessToken(long time,
 boolean forceUpdate)
                           throws AccessTokenException

Overrides:

getAccessToken in class DefaultCachedAccessTokenProvider

Throws:

AccessTokenException

schedulePreemptiveRefresh

protected void schedulePreemptiveRefresh(long time,
 AbstractCachedAccessTokenProvider.AccessTokenCacheItem cache)

loadAccessTokenFromProvider

protected AbstractCachedAccessTokenProvider.AccessTokenCacheItem loadAccessTokenFromProvider(long time)
                                                                                      throws AccessTokenException

Overrides:

loadAccessTokenFromProvider in class DefaultCachedAccessTokenProvider

Throws:

AccessTokenException

preemptiveRefresh

protected void preemptiveRefresh(long time,
 AbstractCachedAccessTokenProvider.AccessTokenCacheItem cache,
 boolean forceRefresh)

Preemptive update.

Parameters:

time - current time

cache - current cache (non-null)

forceRefresh - force refresh

createCacheItem

protected AbstractCachedAccessTokenProvider.AccessTokenCacheItem createCacheItem(long time,
 AccessToken accessToken)

Overrides:

createCacheItem in class DefaultCachedAccessTokenProvider

getExecutorService

public ExecutorService getExecutorService()

Return the executor service which services the background refresh.

Returns:

executor service

getTime

protected String getTime(long update)

getEagerScheduledFuture

protected ScheduledFuture<?> getEagerScheduledFuture()

close

public void close()
           throws IOException

Specified by:

close in interface AutoCloseable

Specified by:

close in interface Closeable

Overrides:

close in class DefaultCachedAccessTokenProvider

Throws:

IOException