Package org.eclipse.aether.named.support

Class Retry

java.lang.Object

org.eclipse.aether.named.support.Retry

public final class Retry
extends Object

Retry helper: retries given Callable as long as it returns null (interpreted as "no answer yet") or given time passes. This helper implements similar semantics regarding caller threads as Lock.tryLock(long, TimeUnit) method does: blocks the caller thread until operation return non-null value within the given waiting time and the current thread has not been interrupted.

Since:

1.7.3

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	Retry.DoNotRetry	Marker interface to apply onto exceptions to make them "never retried" when thrown.

Method Summary

Modifier and Type	Method	Description
static <R> R	retry(int attempts, long sleepMillis, Callable<R> operation, Predicate<Exception> retryPredicate, R defaultResult)	Retries attempting max given times the passed in operation, sleeping given sleepMills between retries.
static <R> R	retry(long time, TimeUnit unit, long sleepMillis, Callable<R> operation, Predicate<Exception> retryPredicate, R defaultResult)	Retries for given amount of time (time, unit) the passed in operation, sleeping given sleepMills between retries.

Methods inherited from class java.lang.Object

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

Method Details

retry

public static <R> R retry(long time,
 TimeUnit unit,
 long sleepMillis,
 Callable<R> operation,
 Predicate<Exception> retryPredicate,
 R defaultResult)
                   throws InterruptedException

Retries for given amount of time (time, unit) the passed in operation, sleeping given sleepMills between retries. In case operation returns null, it is assumed "is not done yet" state, so retry will happen (if time barrier allows). If time barrier passes, and still null ("is not done yet") is returned from operation, the defaultResult is returned.

Throws:

InterruptedException

retry

public static <R> R retry(int attempts,
 long sleepMillis,
 Callable<R> operation,
 Predicate<Exception> retryPredicate,
 R defaultResult)
                   throws InterruptedException

Retries attempting max given times the passed in operation, sleeping given sleepMills between retries. In case operation returns null, it is assumed "is not done yet" state, so retry will happen (if attempt count allows). If all attempts used, and still null ("is not done yet") is returned from operation, the defaultResult is returned.

Just to clear things up: 5 attempts is really 4 retries (once do it and retry 4 times). 0 attempts means "do not even try it", and this method returns without doing anything.

Throws:

InterruptedException