Package com.norconex.commons.lang.exec

Class Retrier

java.lang.Object
com.norconex.commons.lang.exec.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 Details

    • DEFAULT_MAX_RETRIES

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

    • DEFAULT_RETRY_DELAY

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

    • DEFAULT_MAX_CAUSES_KEPT

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

  • Constructor Details

    • 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 Details

    • 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.

    • equals

      public boolean equals(Object other)
      Overrides:
      equals in class Object

    • hashCode

      public int hashCode()
      Overrides:
      hashCode in class Object

    • toString

      public String toString()
      Overrides:
      toString in class Object