org.sodeac.common.function

Class SmartSupplier<T>

java.lang.Object

org.sodeac.common.function.SmartSupplier<T>

Type Parameters:

T - the type of results supplied by wrapped supplier

All Implemented Interfaces:

Supplier<T>

public class SmartSupplier<T>
extends Object
implements Supplier<T>

wrapper for Supplier with additional features

Author:

Sebastian Palarus

Method Summary

Modifier and Type	Method and Description
static <T> SmartSupplier<T>	forSupplier(Supplier<T> wrappedSupplier) create smart supplier
T	get()
static <T> T	supplyPeriodically(Supplier<T> supplier, int attemptCount, int waitTimeValue, TimeUnit waitTimeUnit) get value from Supplier with multiple attempts
static <T> T	supplyPeriodicallyOrDefault(Supplier<T> supplier, int attemptCount, int waitTimeValue, TimeUnit waitTimeUnit, T defaultValue) get value from Supplier with multiple attempts
SmartSupplier<T>	useCacheAfterFailedAttemptsCount(int failedAttemptCount) instruct to use cached value (if exists) after x times the wrapped supplier returns null-value
SmartSupplier<T>	withAttemptCount(int attemptCount) instruct smart supplier to retry Supplier.get() multiple time, if wrapped supplier returns null-value
SmartSupplier<T>	withCacheExpireTime(int cacheExpireTimeValue, TimeUnit cacheExpireTimeUnit) define expire time for cached value
SmartSupplier<T>	withDefaultValue(T defaultValue) define default value, if supplier return no not-null-value
SmartSupplier<T>	withWaitTimeForNextAttempt(int waitTimeValue, TimeUnit waitTimeUnit) define wait time for next retry - @see withAttemptCount(int)

Methods inherited from class java.lang.Object

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

Method Detail

forSupplier

public static <T> SmartSupplier<T> forSupplier(Supplier<T> wrappedSupplier)

create smart supplier

Parameters:

wrappedSupplier - wrapped supplier

Returns:

withAttemptCount

public SmartSupplier<T> withAttemptCount(int attemptCount)

instruct smart supplier to retry Supplier.get() multiple time, if wrapped supplier returns null-value

Parameters:

attemptCount - counts to attempt

Returns:

smart supplier

withWaitTimeForNextAttempt

public SmartSupplier<T> withWaitTimeForNextAttempt(int waitTimeValue,
                                                   TimeUnit waitTimeUnit)

define wait time for next retry - @see withAttemptCount(int)

Parameters:

waitTimeValue - wait time until next attempt to get next value

waitTimeUnit - wait time unit until next attempt to get next value

Returns:

smart supplier

withDefaultValue

public SmartSupplier<T> withDefaultValue(T defaultValue)

define default value, if supplier return no not-null-value

Parameters:

defaultValue - value to supply, if wrapped supplier return no not-null-value

Returns:

smart supplier

useCacheAfterFailedAttemptsCount

public SmartSupplier<T> useCacheAfterFailedAttemptsCount(int failedAttemptCount)

instruct to use cached value (if exists) after x times the wrapped supplier returns null-value

Parameters:

failedAttemptCount - how often wrapped supplier returns null-value until cached value will returns

Returns:

smart supplier

withCacheExpireTime

public SmartSupplier<T> withCacheExpireTime(int cacheExpireTimeValue,
                                            TimeUnit cacheExpireTimeUnit)

define expire time for cached value

Parameters:

cacheExpireTimeValue - expire time value for cached value

cacheExpireTimeUnit - expire time unit for cached value

Returns:

smart supplier

get

public T get()

Specified by:

get in interface Supplier<T>

supplyPeriodicallyOrDefault

public static <T> T supplyPeriodicallyOrDefault(Supplier<T> supplier,
                                                int attemptCount,
                                                int waitTimeValue,
                                                TimeUnit waitTimeUnit,
                                                T defaultValue)

get value from Supplier with multiple attempts

Parameters:

supplier - wrapped supplier

attemptCount - count of attempts

waitTimeValue - wait time until next attempt to get next value

waitTimeUnit - wait time unit until next attempt to get next value

defaultValue - value to return, if supplier supplies no value

Returns:

supplied value, or default value, if supplier supplied no value

supplyPeriodically

public static <T> T supplyPeriodically(Supplier<T> supplier,
                                       int attemptCount,
                                       int waitTimeValue,
                                       TimeUnit waitTimeUnit)

get value from Supplier with multiple attempts

Parameters:

supplier - wrapped supplier

attemptCount - count of attempts

waitTimeValue - wait time until next attempt to get next value

waitTimeUnit - wait time unit until next attempt to get next value

Returns:

supplied value, or null, if supplier supplied no value