net.secodo.jcircuitbreaker.breaker

Interface CircuitBreaker<R>

Type Parameters:

R - the return value of java method (target-method) executed by this circuit breaker. For methods which does not return value Void should be used.

All Known Implementing Classes:

AbstractCircuitBreaker, DefaultCircuitBreaker, ReusableCircuitBreaker

public interface CircuitBreaker<R>

This interface defines the circuit breaker contract.

For details refer to comments on methods.

Method Summary

Modifier and Type	Method and Description
default R	execute(Task<R> task, BreakStrategy<R> breakStrategy, BreakHandler<R> breakHandler) Executes the given Task only when given BreakStrategy allows the execution at the time of call.
<U> R	execute(Task<R> task, BreakStrategy<R> breakStrategy, BreakHandler<R> breakHandler, U userData) Executes the given Task only when given BreakStrategy allows the execution at the time of call.

Method Detail

execute

default R execute(Task<R> task,
                  BreakStrategy<R> breakStrategy,
                  BreakHandler<R> breakHandler)
           throws TaskExecutionException,
                  BreakHandlerException,
                  CircuitBreakerException

Executes the given Task only when given BreakStrategy allows the execution at the time of call. If execution is not allowed BreakHandler is used to handle this situation and return fallback value.

Parameters:

task - encapsulates java method to be executed - called target-method in this context

breakStrategy - decides whether to execute the task or prevent execution and executed breakHandler instead

breakHandler - handles the situation when the strategy does not allow method execution

Returns:

the return value of the executed task or the fallback value returned by breakHandler in case of execution of method did not take place

Throws:

TaskExecutionException - if execution of task resulted in exception

BreakHandlerException - if breakHandler (if executed) could not provide the fallback value

CircuitBreakerException - if unexpected problem occurred while processing the task within CircuitBreaker

execute

<U> R execute(Task<R> task,
              BreakStrategy<R> breakStrategy,
              BreakHandler<R> breakHandler,
              U userData)
       throws TaskExecutionException,
              BreakHandlerException,
              CircuitBreakerException

Executes the given Task only when given BreakStrategy allows the execution at the time of call. If execution is not allowed BreakHandler is used to handle this situation and return fallback value.

Allows to pass some custom data to the strategy which will be available via ExecutionContext.getUserData()

Type Parameters:

U - the type of user data passed to execution context

Parameters:

task - encapsulates java method to be executed - called target-method in this context

breakStrategy - decides whether to execute the task or prevent execution and executed breakHandler instead

breakHandler - handles the situation when the strategy does not allow method execution

userData - custom user data which will be available to strategies via ExecutionContext.getUserData()

Returns:

the return value of the executed task or the fallback value returned by breakHandler in case of execution of method did not take place

Throws:

TaskExecutionException - if execution of task resulted in exception

BreakHandlerException - if breakHandler (if executed) could not provide the fallbackvalue

CircuitBreakerException - if the method execution resulted in exception or breakHandler resulted in exception