dev.failsafe

Class Failsafe

java.lang.Object

dev.failsafe.Failsafe

public class Failsafe
extends Object

Simple, sophisticated failure handling.

Constructor Summary

Constructors

Constructor and Description
Failsafe()

Method Summary

Modifier and Type	Method and Description
static <R> FailsafeExecutor<R>	none() Creates and returns a noop FailsafeExecutor instance that treats any exception as a failure for the purposes of calling event listeners, and provides no additional failure handling.
static <R> FailsafeExecutor<R>	with(List<? extends Policy<R>> policies) Creates and returns a new FailsafeExecutor instance that will handle failures according to the given policies.
static <R,P extends Policy<R>> FailsafeExecutor<R>	with(P outerPolicy, P... policies) Creates and returns a new FailsafeExecutor instance that will handle failures according to the given outerPolicy and policies.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Failsafe

public Failsafe()

Method Detail

with

@SafeVarargs
public static <R,P extends Policy<R>> FailsafeExecutor<R> with(P outerPolicy,
                                                                            P... policies)

Creates and returns a new FailsafeExecutor instance that will handle failures according to the given outerPolicy and policies. The policies are composed around an execution and will handle execution results in reverse, with the last policy being applied first. For example, consider:

   Failsafe.with(fallback, retryPolicy, circuitBreaker).get(supplier);
 

This is equivalent to composition using the the compose method:

   Failsafe.with(fallback).compose(retryPolicy).compose(circuitBreaker).get(supplier);
 

These result in the following internal composition when executing a runnable or supplier and handling its result:

   Fallback(RetryPolicy(CircuitBreaker(Supplier)))
 

This means the CircuitBreaker is first to evaluate the Supplier's result, then the RetryPolicy, then the Fallback. Each policy makes its own determination as to whether the result represents a failure. This allows different policies to be used for handling different types of failures.

Type Parameters:

R - result type

P - policy type

Throws:

NullPointerException - if outerPolicy is null

with

public static <R> FailsafeExecutor<R> with(List<? extends Policy<R>> policies)

Creates and returns a new FailsafeExecutor instance that will handle failures according to the given policies. The policies are composed around an execution and will handle execution results in reverse, with the last policy being applied first. For example, consider:

   Failsafe.with(Arrays.asList(fallback, retryPolicy, circuitBreaker)).get(supplier);
 

This results in the following internal composition when executing a runnable or supplier and handling its result:

   Fallback(RetryPolicy(CircuitBreaker(Supplier)))
 

This means the CircuitBreaker is first to evaluate the Supplier's result, then the RetryPolicy, then the Fallback. Each policy makes its own determination as to whether the result represents a failure. This allows different policies to be used for handling different types of failures.

Type Parameters:

R - result type

Throws:

NullPointerException - if policies is null

IllegalArgumentException - if policies is empty

none

public static <R> FailsafeExecutor<R> none()

Creates and returns a noop FailsafeExecutor instance that treats any exception as a failure for the purposes of calling event listeners, and provides no additional failure handling.

Type Parameters:

R - result type

Throws:

NullPointerException - if policies is null

IllegalArgumentException - if policies is empty