Package org.kiwiproject.retry

Class SimpleRetryer

java.lang.Object
org.kiwiproject.retry.SimpleRetryer
public class SimpleRetryer extends Object
A simple class to retry an operation up to a maximum number of attempts. Uses the same set of initial values for maximum number of attempts, delay between attempts, etc. Consider using this rather than SimpleRetries directly.

You can construct a SimpleRetryer using the builder obtained via SimpleRetryer.builder().

Available configuration options for SimpleRetryer:
Name Default Description
environment a DefaultEnvironment instance mainly useful for testing, e.g. to supply a mock
maxAttempts DEFAULT_MAX_ATTEMPTS the maximum number of attempts to make before giving up
retryDelayTime DEFAULT_RETRY_DELAY_TIME the time value to wait between attempts
retryDelayUnit DEFAULT_RETRY_DELAY_UNIT the time unit for retryDelayTime
commonType DEFAULT_TYPE use this to specify a common type/description that retryer will get (used in log messages)
logLevelForSubsequentAttempts DEFAULT_RETRY_LOG_LEVEL the log level at which retries will be logged (the first attempt is always logged at TRACE)
Implementation Note:
This is basically an instance wrapper around SimpleRetries to allow for specification of common configuration, and thus avoid calling methods with many parameters. It also facilitates easy mocking in tests as opposed to the static methods in SimpleRetries.

  • Field Details

    • DEFAULT_MAX_ATTEMPTS

      public static final int DEFAULT_MAX_ATTEMPTS
      Default maximum attempts.
      See Also:

    • DEFAULT_RETRY_DELAY_TIME

      public static final long DEFAULT_RETRY_DELAY_TIME
      Default retry delay time. This is a static value, i.e. there is no fancy exponential or linear backoff.
      See Also:

    • DEFAULT_RETRY_DELAY_UNIT

      public static final TimeUnit DEFAULT_RETRY_DELAY_UNIT
      Default retry delay time unit.

    • DEFAULT_TYPE

      public static final String DEFAULT_TYPE
      Default value to include in attempt log messages.
      See Also:

    • DEFAULT_RETRY_LOG_LEVEL

      public static final org.slf4j.event.Level DEFAULT_RETRY_LOG_LEVEL
      Default value of the log level to use when logging retry attempts.

  • Method Details

    • tryGetObject

      public <T> Optional<T> tryGetObject(Supplier<T> supplier)
      Try to get an object.
      Type Parameters:
      T - the type of object
      Parameters:
      supplier - on success return the object; return null or throw exception if attempt failed
      Returns:
      an Optional which either contains a value, or is empty if all attempts failed

    • tryGetObject

      public <T> Optional<T> tryGetObject(Class<T> type, Supplier<T> supplier)
      Try to get an object.
      Type Parameters:
      T - the type of object
      Parameters:
      type - the type of object to return, used only in logging messages
      supplier - on success return the object; return null or throw exception if attempt failed
      Returns:
      an Optional which either contains a value, or is empty if all attempts failed

    • tryGetObject

      public <T> Optional<T> tryGetObject(String type, Supplier<T> supplier)
      Try to get an object.
      Type Parameters:
      T - the type of object
      Parameters:
      type - the type of object to return, used only in logging messages
      supplier - on success return the object; return null or throw exception if attempt failed
      Returns:
      an Optional which either contains a value, or is empty if all attempts failed

    • tryGetObjectCollectingErrors

      public <T> RetryResult<T> tryGetObjectCollectingErrors(Supplier<T> supplier)
      Try to get an object.
      Type Parameters:
      T - the type of object
      Parameters:
      supplier - on success return the object; return null or throw exception if attempt failed
      Returns:
      a RetryResult

    • tryGetObjectCollectingErrors

      public <T> RetryResult<T> tryGetObjectCollectingErrors(Class<T> type, Supplier<T> supplier)
      Try to get an object.
      Type Parameters:
      T - the type of object
      Parameters:
      type - the type of object to return, used only in logging messages
      supplier - on success return the object; return null or throw exception if attempt failed
      Returns:
      a RetryResult

    • tryGetObjectCollectingErrors

      public <T> RetryResult<T> tryGetObjectCollectingErrors(String type, Supplier<T> supplier)
      Try to get an object.
      Type Parameters:
      T - the type of object
      Parameters:
      type - the type of object to return, used only in logging messages
      supplier - on success return the object; return null or throw exception if attempt failed
      Returns:
      a RetryResult

    • builder

      public static SimpleRetryer.SimpleRetryerBuilder builder()