Retrier (JBL)

java.lang.Object
- org.swblocks.jbl.util.retry.Retrier

public final class Retrier
extends java.lang.Object

The action retry logic encapsulation.

The Retrier executes an action and can be passed a predicate to determine if a retry should occur on failure.

Example usage to create an ActionRetrier with a default time generator to pause for 5 seconds and repeat 10 times (retries). The retrier will run an action and the result will be tested to see if it should be retried.

      final ActionRetrier retrier =
              Retrier.createSleepRetrier(Retrier.createConstantTimeGenerator(5000), 10);

      final Predicate<Result> predicate =
              Retrier.exceptionsFilterPredicate(IllegalArgumentException.class);

      // always fails and will retry...
      final Result result =
              retrier.run(() -> Result.failure(() -> new Exception()), predicate);

      // more code

The class is configured with a number of static members and methods to create default time generators and action retriers.

Example to create an ActionRetrier using the default capped incrementing time generator with 5 retry attempts:

      final ActionRetrier retrier =
              Retrier.createSleepRetrier(Retrier.DEFAULT_CAPPED_INCREMENTING_TIME_GENERATOR, 5);

      // default - filter all
      final Predicate<Result> predicate = Retrier.PREDICATE_EXCEPTIONS_FILTER_ALL;

      // will not retry as predicate test fails...
      final Result result = retrier.run(() -> Result.failure(() -> new Exception()), predicate);

     // more code

Field Summary

Fields
Modifier and Type	Field and Description
`static java.util.function.Supplier<java.util.Iterator<java.lang.Long>>`	`DEFAULT_CAPPED_INCREMENTING_TIME_GENERATOR`
`static java.util.function.Supplier<java.util.Iterator<java.lang.Long>>`	`DEFAULT_CONSTANT_TIME_GENERATOR`
`static long`	`TIME_GENERATOR_DEFAULT_CAPPED_DELAY_IN_MILLISECONDS`
`static long`	`TIME_GENERATOR_DEFAULT_DELAY_IN_MILLISECONDS`
`static int`	`TIME_GENERATOR_DEFAULT_RETRIES_BETWEEN_STEPS`
`static long`	`TIME_GENERATOR_DEFAULT_STEP_MULTIPLIER`

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static java.util.function.Supplier<java.util.Iterator<java.lang.Long>>`	`createCappedIncrementingTimeGenerator(long initialDelayInMillis, long cappedDelayInMillis, long stepMultiplier, int retriesBetweenSteps)` Method to create a capped time incrementing time generator (iterator) from the specified arguments.
`static java.util.function.Supplier<java.util.Iterator<java.lang.Long>>`	`createConstantTimeGenerator(long timeInMiliseconds)` Create a constant time generator.
`static <T> ActionRetrier<T>`	`createContinuousSleepRetrier(java.util.function.Supplier<java.util.Iterator<java.lang.Long>> timeGenerator)` Method to create an ActionRetrier that has no limit on the the number of retry attempts.
`static <T> ActionRetrier<T>`	`createDefaultCappedIncrementingRetrier()` Create a retrier that that will increment the time between retry attempts if a failure occurs.
`static <T> ActionRetrier<T>`	`createDefaultContinuousCappedIncrementingRetrier()` Create a retrier that will keep retrying the action until success and incrementing the time between attempts.
`static <T> ActionRetrier<T>`	`createDefaultContinuousConstantSleepRetrier()` Create a retrier that will continually retry with a constant time between retry attempts.
`static <T> java.util.function.Predicate<Result<T>>`	`createDefaultExceptionPredicate()` A predicate that returns true for any exceptions derived from `Exception`.
`static <T> ActionRetrier<T>`	`createDefaultSingleSleepRetrier()` Create a retrier that will retry an action once if the action fails.
`static <T> ActionRetrier<T>`	`createNonRetrier()` Create a retrier that executes the action once only and will never retry.
`static <T> ActionRetrier<T>`	`createSleepRetrier(java.util.function.Supplier<java.util.Iterator<java.lang.Long>> timeGenerator, int numberOfRetries)` Method to return a ActionRetrier to execute an action.
`static <T> java.util.function.Predicate<Result<T>>`	`exceptionsFilterPredicate(java.lang.Class... recoverableTypes)` A predicate that matches against a set of exception types.

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

- Field Detail
  - TIME_GENERATOR_DEFAULT_DELAY_IN_MILLISECONDS
```
public static final long TIME_GENERATOR_DEFAULT_DELAY_IN_MILLISECONDS
```
    See Also:
    
    Constant Field Values
  - TIME_GENERATOR_DEFAULT_CAPPED_DELAY_IN_MILLISECONDS
```
public static final long TIME_GENERATOR_DEFAULT_CAPPED_DELAY_IN_MILLISECONDS
```
  - TIME_GENERATOR_DEFAULT_STEP_MULTIPLIER
```
public static final long TIME_GENERATOR_DEFAULT_STEP_MULTIPLIER
```
    See Also:
    
    Constant Field Values
  - TIME_GENERATOR_DEFAULT_RETRIES_BETWEEN_STEPS
```
public static final int TIME_GENERATOR_DEFAULT_RETRIES_BETWEEN_STEPS
```
    See Also:
    
    Constant Field Values
  - DEFAULT_CAPPED_INCREMENTING_TIME_GENERATOR
```
public static final java.util.function.Supplier<java.util.Iterator<java.lang.Long>> DEFAULT_CAPPED_INCREMENTING_TIME_GENERATOR
```
  - DEFAULT_CONSTANT_TIME_GENERATOR
```
public static final java.util.function.Supplier<java.util.Iterator<java.lang.Long>> DEFAULT_CONSTANT_TIME_GENERATOR
```
- Method Detail
  - createDefaultExceptionPredicate
```
public static <T> java.util.function.Predicate<Result<T>> createDefaultExceptionPredicate()
```
    A predicate that returns true for any exceptions derived from Exception.
    
    Type Parameters:
    
    T - the type of object
    
    Returns:
    
    the predicate to perform the check
  - exceptionsFilterPredicate
```
public static <T> java.util.function.Predicate<Result<T>> exceptionsFilterPredicate(java.lang.Class... recoverableTypes)
```
    A predicate that matches against a set of exception types.
    
    Type Parameters:
    
    T - the object type
    
    Parameters:
    
    recoverableTypes - The recoverable exception types
    
    Returns:
    
    The predicate to perform the test
  - createNonRetrier
```
public static <T> ActionRetrier<T> createNonRetrier()
```
    Create a retrier that executes the action once only and will never retry.
    
    Type Parameters:
    
    T - the object type
    
    Returns:
    
    the ActionRetrier
  - createDefaultSingleSleepRetrier
```
public static <T> ActionRetrier<T> createDefaultSingleSleepRetrier()
```
    Create a retrier that will retry an action once if the action fails.
    
    Type Parameters:
    
    T - the object type
    
    Returns:
    
    the ActionRetrier
  - createDefaultContinuousConstantSleepRetrier
```
public static <T> ActionRetrier<T> createDefaultContinuousConstantSleepRetrier()
```
    Create a retrier that will continually retry with a constant time between retry attempts.
    
    Type Parameters:
    
    T - the object type
    
    Returns:
    
    the ActionRetrier
  - createDefaultCappedIncrementingRetrier
```
public static <T> ActionRetrier<T> createDefaultCappedIncrementingRetrier()
```
    Create a retrier that that will increment the time between retry attempts if a failure occurs.
    
    Type Parameters:
    
    T - the object type
    
    Returns:
    
    the ActionRetrier
  - createDefaultContinuousCappedIncrementingRetrier
```
public static <T> ActionRetrier<T> createDefaultContinuousCappedIncrementingRetrier()
```
    Create a retrier that will keep retrying the action until success and incrementing the time between attempts.
    
    Type Parameters:
    
    T - the object type
    
    Returns:
    
    the ActionRetrier
  - createSleepRetrier
```
public static <T> ActionRetrier<T> createSleepRetrier(java.util.function.Supplier<java.util.Iterator<java.lang.Long>> timeGenerator,
                                                      int numberOfRetries)
```
    Method to return a ActionRetrier to execute an action.
    
    Type Parameters:
    
    T - the object type
    
    Parameters:
    
    timeGenerator - the time generator used to derive sleep times
    
    numberOfRetries - the number of retry attempts
    
    Returns:
    
    the ActionRetrier
  - createContinuousSleepRetrier
```
public static <T> ActionRetrier<T> createContinuousSleepRetrier(java.util.function.Supplier<java.util.Iterator<java.lang.Long>> timeGenerator)
```
    Method to create an ActionRetrier that has no limit on the the number of retry attempts.
    
    Type Parameters:
    
    T - the object type
    
    Parameters:
    
    timeGenerator - the time generator used to derive sleep times
    
    Returns:
    
    the ActionRetrier
  - createConstantTimeGenerator
```
public static java.util.function.Supplier<java.util.Iterator<java.lang.Long>> createConstantTimeGenerator(long timeInMiliseconds)
```
    Create a constant time generator.
    
    Parameters:
    
    timeInMiliseconds - the time that the generator will always return
    
    Returns:
    
    the iterator that always returns the defined time
  - createCappedIncrementingTimeGenerator
```
public static java.util.function.Supplier<java.util.Iterator<java.lang.Long>> createCappedIncrementingTimeGenerator(long initialDelayInMillis,
                                                                                                                    long cappedDelayInMillis,
                                                                                                                    long stepMultiplier,
                                                                                                                    int retriesBetweenSteps)
```
    Method to create a capped time incrementing time generator (iterator) from the specified arguments.
    Once the number of retries has been exceeded, the delay is incremented by the step until the maximum delay has been reached. The delay will never exceed the capped delay.
    
    Parameters:
    
    initialDelayInMillis - the initial delay in milliseconds that should be used for the sleep time
    
    cappedDelayInMillis - the maximum delay in milliseconds that the time generator will return
    
    stepMultiplier - the step multiplier that is applied to the current time delay
    
    retriesBetweenSteps - the number of retries that are attempted before the step multiplier is applied
    
    Returns:
    
    the iterator that returns the calulated sleep times

Class Retrier

Field Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

TIME_GENERATOR_DEFAULT_DELAY_IN_MILLISECONDS

TIME_GENERATOR_DEFAULT_CAPPED_DELAY_IN_MILLISECONDS

TIME_GENERATOR_DEFAULT_STEP_MULTIPLIER

TIME_GENERATOR_DEFAULT_RETRIES_BETWEEN_STEPS

DEFAULT_CAPPED_INCREMENTING_TIME_GENERATOR

DEFAULT_CONSTANT_TIME_GENERATOR

Method Detail

createDefaultExceptionPredicate

exceptionsFilterPredicate

createNonRetrier

createDefaultSingleSleepRetrier

createDefaultContinuousConstantSleepRetrier

createDefaultCappedIncrementingRetrier

createDefaultContinuousCappedIncrementingRetrier

createSleepRetrier

createContinuousSleepRetrier

createConstantTimeGenerator

createCappedIncrementingTimeGenerator