Package com.norconex.commons.lang.exec

Class Retrier

  • public class Retrier
extends Object
    This class is responsible for executing IRetriable instances. Upon reaching the maximum number of retries allowed, it will throw a RetriableException, wrapping the last exceptions encountered, if any, to a configurable maximum.
    Since:
    1.13.0
    Author:
    Pascal Essiembre

    • Field Detail

      • DEFAULT_MAX_RETRIES

        public static final int DEFAULT_MAX_RETRIES
        Default maximum number of retries.
        See Also:
        Constant Field Values

      • DEFAULT_RETRY_DELAY

        public static final long DEFAULT_RETRY_DELAY
        Default wait time (milliseconds) before making a new attempt.
        See Also:
        Constant Field Values

      • DEFAULT_MAX_CAUSES_KEPT

        public static final int DEFAULT_MAX_CAUSES_KEPT
        Default maximum number of exception causes kept.
        See Also:
        Constant Field Values

    • Constructor Detail

      • Retrier

        public Retrier()
        Creates a new instance with the default maximum retries and default retry delay (no delay).

      • Retrier

        public Retrier​(int maxRetries)
        Creates a new instance with the default retry delay (no delay).
        Parameters:
        maxRetries - maximum number of execution retries

      • Retrier

        public Retrier​(IExceptionFilter exceptionFilter)
        Creates a new instance which will retry execution only if the exception thrown by an attempt is accepted by the IExceptionFilter (up to maxRetries). Uses the default maximum retries and default retry delay.
        Parameters:
        exceptionFilter - exception filter

      • Retrier

        public Retrier​(IExceptionFilter exceptionFilter,
               int maxRetries)
        Creates a new instance which will retry execution only if the exception thrown by an attempt is accepted by the IExceptionFilter (up to maxRetries).
        Parameters:
        exceptionFilter - exception filter
        maxRetries - maximum number of retries

    • Method Detail

      • getMaxRetries

        public int getMaxRetries()
        Gets the maximum number of retries (the initial run does not count as a retry).
        Returns:
        maximum number of retries

      • setMaxRetries

        public Retrier setMaxRetries​(int maxRetries)
        Sets the maximum number of retries (the initial run does not count as a retry).
        Parameters:
        maxRetries - maximum number of retries
        Returns:
        this instance

      • getRetryDelay

        public long getRetryDelay()
        Gets the delay in milliseconds before attempting to execute again.
        Returns:
        delay in milliseconds

      • setRetryDelay

        public Retrier setRetryDelay​(long retryDelay)
        Sets the delay in milliseconds before attempting to execute again.
        Parameters:
        retryDelay - delay in milliseconds
        Returns:
        this instance

      • getExceptionFilter

        public IExceptionFilter getExceptionFilter()
        Sets an exception filter that limits the exceptions eligible for retry.
        Returns:
        exception filter

      • setExceptionFilter

        public Retrier setExceptionFilter​(IExceptionFilter exceptionFilter)
        Sets an exception filter that limits the exceptions eligible for retry.
        Parameters:
        exceptionFilter - exception filter
        Returns:
        this instance

      • getMaxCauses

        public int getMaxCauses()
        Gets the maximum number of exception causes to keep when all attempts were made and a RetriableException is thrown.
        Returns:
        max number of causes

      • setMaxCauses

        public Retrier setMaxCauses​(int maxCauses)
        Sets the maximum number of exception causes to keep when all attempts were made and a RetriableException is thrown.
        Parameters:
        maxCauses - max number of causes
        Returns:
        this instance

      • execute

        public <T> T execute​(IRetriable<T> retriable)
              throws RetriableException
        Runs the IRetriable instance. This method is only thread-safe if not modified after being used for the first time, and the exception filter is thread-safe (or null).
        Type Parameters:
        T - type of optional return value
        Parameters:
        retriable - the code to run
        Returns:
        execution output if any, or null
        Throws:
        RetriableException - wrapper around last exception encountered or exception thrown when max rerun attempts is reached.

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class Object