Retry (Reactor Core 3.5.21 API)

java.lang.Object
- reactor.util.retry.Retry

Direct Known Subclasses:

RetryBackoffSpec, RetrySpec
```
public abstract class Retry
extends Object
```
Base abstract class for a strategy to decide when to retry given a companion Flux of Retry.RetrySignal, for use with Flux.retryWhen(Retry) and Mono.retryWhen(Retry). Also provides access to configurable built-in strategies via static factory methods:
Users are encouraged to provide either concrete custom Retry strategies or builders that produce such concrete Retry. The RetrySpec returned by e.g. max(long) is a good inspiration for a fluent approach that generates a Retry at each step and uses immutability/copy-on-write to enable sharing of intermediate steps (that can thus be considered templates).
Author:

Simon Baslé

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static interface`	`Retry.RetrySignal` State used in `Flux.retryWhen(Retry)` and `Mono.retryWhen(Retry)`, providing the `Throwable` that caused the source to fail as well as counters keeping track of retries.

Field Summary

Fields
Modifier and Type Field and Description

ContextView retryContext

Fields
Modifier and Type	Field and Description
`ContextView`	`retryContext`

Constructor Summary

Constructors
Modifier Constructor and Description

Retry()

protected Retry(ContextView retryContext)

Constructors
Modifier	Constructor and Description
	`Retry()`
`protected`	`Retry(ContextView retryContext)`

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`static RetryBackoffSpec`	`backoff(long maxAttempts, Duration minBackoff)` A `RetryBackoffSpec` preconfigured for exponential backoff strategy with jitter, given a maximum number of retry attempts and a minimum `Duration` for the backoff.
`static RetryBackoffSpec`	`fixedDelay(long maxAttempts, Duration fixedDelay)` A `RetryBackoffSpec` preconfigured for fixed delays (min backoff equals max backoff, no jitter), given a maximum number of retry attempts and the fixed `Duration` for the backoff.
`static Retry`	`from(Function<Flux<Retry.RetrySignal>,? extends Publisher<?>> function)` A wrapper around `Function` to provide `Retry` by using lambda expressions.
`abstract Publisher<?>`	`generateCompanion(Flux<Retry.RetrySignal> retrySignals)` Generates the companion publisher responsible for reacting to incoming `Retry.RetrySignal` emissions, effectively deciding when to retry.
`static RetrySpec`	`indefinitely()` A `RetrySpec` preconfigured for the most simplistic retry strategy: retry immediately and indefinitely (similar to `Flux.retry()`).
`static RetrySpec`	`max(long max)` A `RetrySpec` preconfigured for a simple strategy with maximum number of retry attempts.
`static RetrySpec`	`maxInARow(long maxInARow)` A `RetrySpec` preconfigured for a simple strategy with maximum number of retry attempts over subsequent transient errors.
`ContextView`	`retryContext()` Return the user provided context that was set at construction time.
`static Retry`	`withThrowable(Function<Flux<Throwable>,? extends Publisher<?>> function)` An adapter for `Flux` of `Throwable`-based `Function` to provide `Retry` from a legacy retryWhen `Function`.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - retryContext
```
public final ContextView retryContext
```
- Constructor Detail
  - Retry
```
public Retry()
```
  - Retry
```
protected Retry(ContextView retryContext)
```
- Method Detail
  - generateCompanion
```
public abstract Publisher<?> generateCompanion(Flux<Retry.RetrySignal> retrySignals)
```
    Generates the companion publisher responsible for reacting to incoming Retry.RetrySignal emissions, effectively deciding when to retry.
    When the source signals an error, that onError signal will be suppressed. Its Throwable will instead be attached to a Retry.RetrySignal, immediately emitted on the retrySignals publisher. Right after that emission, request(1) is called on the companion publisher.
    The response to that request decides if a retry should be made. Thus, the outer publisher will wait until a signal is emitted by the companion publisher, making it possible to delay retry attempts.
    Any onNext emitted by the companion publisher triggers a retry, onError will fail the outer publisher and onComplete will complete the outer publisher (effectively suppressing the original error/Throwable).
    As an example, the simplest form of retry companion would be to return the incoming Flux of Retry.RetrySignal without modification. This would render a retry strategy that immediately retries, forever.
    
    Parameters:
    
    retrySignals - the errors from the outer publisher as Retry.RetrySignal objects, containing the Throwable causing the error as well as retry counter metadata.
    
    Returns:
    
    the companion publisher responsible for reacting to incoming Retry.RetrySignal emissions, effectively deciding when to retry.
  - retryContext
```
public ContextView retryContext()
```
    Return the user provided context that was set at construction time.
    
    Returns:
    
    the user provided context that will be accessible via Retry.RetrySignal.retryContextView().
  - backoff
```
public static RetryBackoffSpec backoff(long maxAttempts,
                                       Duration minBackoff)
```
    A RetryBackoffSpec preconfigured for exponential backoff strategy with jitter, given a maximum number of retry attempts and a minimum Duration for the backoff.
    
    Parameters:
    
    maxAttempts - the maximum number of retry attempts to allow
    
    minBackoff - the minimum Duration for the first backoff
    
    Returns:
    
    the exponential backoff spec for further configuration
    
    See Also:
    
    RetryBackoffSpec.maxAttempts(long), RetryBackoffSpec.minBackoff(Duration)
  - fixedDelay
```
public static RetryBackoffSpec fixedDelay(long maxAttempts,
                                          Duration fixedDelay)
```
    A RetryBackoffSpec preconfigured for fixed delays (min backoff equals max backoff, no jitter), given a maximum number of retry attempts and the fixed Duration for the backoff.
    
    Note that calling RetryBackoffSpec.minBackoff(Duration) or RetryBackoffSpec.maxBackoff(Duration) would switch back to an exponential backoff strategy.
    
    Parameters:
    
    maxAttempts - the maximum number of retry attempts to allow
    
    fixedDelay - the Duration of the fixed delays
    
    Returns:
    
    the fixed delays spec for further configuration
    
    See Also:
    
    RetryBackoffSpec.maxAttempts(long), RetryBackoffSpec.minBackoff(Duration), RetryBackoffSpec.maxBackoff(Duration)
  - max
```
public static RetrySpec max(long max)
```
    A RetrySpec preconfigured for a simple strategy with maximum number of retry attempts.
    
    Parameters:
    
    max - the maximum number of retry attempts to allow
    
    Returns:
    
    the max attempt spec for further configuration
    
    See Also:
    
    RetrySpec.maxAttempts(long)
  - maxInARow
```
public static RetrySpec maxInARow(long maxInARow)
```
    A RetrySpec preconfigured for a simple strategy with maximum number of retry attempts over subsequent transient errors. An Subscriber.onNext(Object) between errors resets the counter (see RetrySpec.transientErrors(boolean)).
    
    Parameters:
    
    maxInARow - the maximum number of retry attempts to allow in a row, reset by successful onNext
    
    Returns:
    
    the max in a row spec for further configuration
    
    See Also:
    
    RetrySpec.maxAttempts(long), RetrySpec.transientErrors(boolean)
  - indefinitely
```
public static RetrySpec indefinitely()
```
    A RetrySpec preconfigured for the most simplistic retry strategy: retry immediately and indefinitely (similar to Flux.retry()).
    
    Returns:
    
    the retry indefinitely spec for further configuration
  - from
```
public static final Retry from(Function<Flux<Retry.RetrySignal>,? extends Publisher<?>> function)
```
    A wrapper around Function to provide Retry by using lambda expressions.
    
    Parameters:
    
    function - the Function representing the desired Retry strategy as a lambda
    
    Returns:
    
    the Retry strategy adapted from the Function
  - withThrowable
```
public static final Retry withThrowable(Function<Flux<Throwable>,? extends Publisher<?>> function)
```
    An adapter for Flux of Throwable-based Function to provide Retry from a legacy retryWhen Function.
    
    Parameters:
    
    function - the Function representing the desired Retry strategy as a lambda
    
    Returns:
    
    the Retry strategy adapted from the Function

Class Retry

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

retryContext

Constructor Detail

Retry

Retry

Method Detail

generateCompanion

retryContext

backoff

fixedDelay

max

maxInARow

indefinitely

from

withThrowable