net.secodo.jcircuitbreaker.breakhandler

Interface BreakHandler<R>

Type Parameters:

R - the return type of onBreak method. This must be the same return type as the of of executed Task

All Known Subinterfaces:

BreakHandlerFactory<R>, OnePerExecutionHandlerFactory<R>

All Known Implementing Classes:

ExceptionThrowingHandler, NoActionHandler, ReturnStaticValueHandler, ReusableRetryHandler, SimpleHandlerFactory, StatefulRetryHandler

public interface BreakHandler<R>

Handles break situation. Can result in different actions to be performed like trying to retry the task or return static fallback value instead.

It's main goal is to provide a fallback value for a method in case the CircuitBreaker decided not to execute the real method. If providing a fallback value is not possible break handler should throw BreakHandlerException

Method Summary

Modifier and Type	Method and Description
R	onBreak(ContextAwareCircuitBreaker<R> circuitBreaker, Task<R> task, BreakStrategy<R> breakStrategy, ExecutionContext<R> executionContext) Handles situation when break occurs.

Method Detail

onBreak

R onBreak(ContextAwareCircuitBreaker<R> circuitBreaker,
          Task<R> task,
          BreakStrategy<R> breakStrategy,
          ExecutionContext<R> executionContext)
   throws TaskExecutionException,
          CircuitBreakerException,
          BreakHandlerException

Handles situation when break occurs. Returns the fallback value in case the break happens.

Parameters:

circuitBreaker - a reference to the ContextAwareCircuitBreaker which called this break handler

task - the task which execution was prevented by break strategy and resulted in calling this break handler

breakStrategy - the strategy which prevented the execution of task and resulted in calling this break handler

executionContext - contains current execution data (specific to current execution)

Returns:

fallback value which replaces the value returned by method call

Throws:

TaskExecutionException - in case there was exception while executing the task by this break handler (but only in case this handler decided to execute the task - there is no possibility to throw TaskExecutionException in case there was no attempt to execute a task)

CircuitBreakerException - in case the break handler tried to execute some task on circuitBreaker but the circuitBreaker fallen with unexpected exception

BreakHandlerException - in case this break handler is not able to provide the the fallback value