FallbackBuilder

java.lang.Object
- dev.failsafe.PolicyBuilder<S,C,R>
- - dev.failsafe.FailurePolicyBuilder<FallbackBuilder<R>,FallbackConfig<R>,R>
  - - dev.failsafe.FallbackBuilder<R>

Type Parameters:

R - result type

All Implemented Interfaces:

PolicyListeners<FallbackBuilder<R>,R>
```
public class FallbackBuilder<R>
extends FailurePolicyBuilder<FallbackBuilder<R>,FallbackConfig<R>,R>
implements PolicyListeners<FallbackBuilder<R>,R>
```
Builds Fallback instances.
- By default, any exception is considered a failure and will be handled by the policy. You can override this by specifying your own handle conditions. The default exception handling condition will only be overridden by another condition that handles failure exceptions such as FailurePolicyBuilder.handle(Class) or FailurePolicyBuilder.handleIf(CheckedBiPredicate). Specifying a condition that only handles results, such as FailurePolicyBuilder.handleResult(Object) or FailurePolicyBuilder.handleResultIf(CheckedPredicate) will not replace the default exception handling condition.
- If multiple handle conditions are specified, any condition that matches an execution result or failure will trigger policy handling.
Note:
- This class extends FailurePolicyBuilder which offers additional configuration.
- This class is not threadsafe.
See Also:

FallbackConfig

Field Summary
- Fields inherited from class dev.failsafe.PolicyBuilder
  config

Constructor Summary

Constructors
Constructor	Description
`FallbackBuilder(FallbackConfig<R> config)`
`FallbackBuilder(CheckedFunction<ExecutionAttemptedEvent<R>,R> fallback, CheckedFunction<ExecutionAttemptedEvent<R>,java.util.concurrent.CompletableFuture<R>> fallbackStage)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`Fallback<R>`	`build()`	Builds a new `Fallback` using the builder's configuration.
`FallbackBuilder<R>`	`onFailedAttempt(EventListener<ExecutionAttemptedEvent<R>> listener)`	Registers the `listener` to be called when the last execution attempt prior to the fallback failed.
`FallbackBuilder<R>`	`withAsync()`	Configures the fallback to run asynchronously.

Methods inherited from class dev.failsafe.FailurePolicyBuilder
failurePredicateFor, failurePredicateFor, handle, handle, handle, handleIf, handleIf, handleResult, handleResultIf, resultPredicateFor, resultPredicateFor

Methods inherited from class dev.failsafe.PolicyBuilder
onFailure, onSuccess

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface dev.failsafe.PolicyListeners
onFailure, onSuccess

- Constructor Detail
  - FallbackBuilder
```
FallbackBuilder(CheckedFunction<ExecutionAttemptedEvent<R>,R> fallback,
                CheckedFunction<ExecutionAttemptedEvent<R>,java.util.concurrent.CompletableFuture<R>> fallbackStage)
```
  - FallbackBuilder
```
FallbackBuilder(FallbackConfig<R> config)
```
- Method Detail
  - build
```
public Fallback<R> build()
```
    Builds a new Fallback using the builder's configuration.
  - onFailedAttempt
```
public FallbackBuilder<R> onFailedAttempt(EventListener<ExecutionAttemptedEvent<R>> listener)
```
    Registers the listener to be called when the last execution attempt prior to the fallback failed. You can also use onFailure to determine when the fallback attempt also fails.
    Note: Any exceptions that are thrown from within the listener are ignored.
    
    Throws:
    
    java.lang.NullPointerException - if listener is null
  - withAsync
```
public FallbackBuilder<R> withAsync()
```
    Configures the fallback to run asynchronously.