Package org.kiwiproject.retry

Class Retryer

java.lang.Object

org.kiwiproject.retry.Retryer

public final class Retryer
extends Object

A retryer, which executes a call, and retries it until it succeeds, or a stop strategy decides to stop retrying. A wait strategy is used to sleep between attempts. The strategy to decide if the call succeeds or not is also configurable.

A retryer can also wrap the callable into a RetryerCallable, which can be submitted to an executor.

Retryer instances are better constructed with a RetryerBuilder. A retryer is thread-safe, provided the arguments passed to its constructor are thread-safe.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	Retryer.RetryerCallable<T>	A Callable which wraps another Callable in order to add retrying behavior from a given Retryer instance.

Method Summary

Modifier and Type	Method	Description
<T> T	call(Callable<T> callable)	Executes the given callable, retrying if necessary.
void	run(Runnable runnable)	Executes the given runnable, retrying if necessary.
<T> Retryer.RetryerCallable<T>	wrap(Callable<T> callable)	Wraps the given Callable in a Retryer.RetryerCallable, which can be submitted to an executor.

Methods inherited from class java.lang.Object

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

Method Detail

call

public <T> T call(Callable<T> callable)
           throws RetryException,
                  InterruptedException

Executes the given callable, retrying if necessary. If the retry predicate accepts the attempt, the stop strategy is used to decide if a new attempt must be made. Then the wait strategy is used to decide how much time to sleep and a new attempt is made.

Type Parameters:

T - the return type of the Callable

Parameters:

callable - the callable task to be executed

Returns:

the computed result of the given callable

Throws:

RetryException - if all the attempts failed before the stop strategy decided to abort

InterruptedException - If this thread is interrupted. This can happen because Thread.sleep(long) is invoked between attempts

run

public void run(Runnable runnable)
         throws RetryException,
                InterruptedException

Executes the given runnable, retrying if necessary. If the retry predicate accepts the attempt, the stop strategy is used to decide if a new attempt must be made. Then the wait strategy is used to decide how much time to sleep and a new attempt is made.

Parameters:

runnable - the runnable task to be executed

Throws:

RetryException - if all the attempts failed before the stop strategy decided to abort

InterruptedException - If this thread is interrupted. This can happen because Thread.sleep(long) is invoked between attempts

wrap

public <T> Retryer.RetryerCallable<T> wrap(Callable<T> callable)

Wraps the given Callable in a Retryer.RetryerCallable, which can be submitted to an executor. The returned Retryer.RetryerCallable uses this Retryer instance to call the given Callable.

Type Parameters:

T - the return type of the Callable

Parameters:

callable - the callable to wrap

Returns:

a Retryer.RetryerCallable that behaves like the given Callable with retry behavior defined by this Retryer