io.smallrye.mutiny.groups

Class UniOnFailure<T>

java.lang.Object

io.smallrye.mutiny.groups.UniOnFailure<T>

Type Parameters:

T - the type of item

public class UniOnFailure<T>
extends Object

Configures the failure handler.

The upstream uni has sent us a failure, this class lets you decide what need to be done in this case. Typically, you can recover with a fallback item (recoverWithItem(Object)), or with another Uni (recoverWithUni(Uni)). You can also retry (retry()). Maybe, you just want to look at the failure (invoke(Consumer)).

You can configure the type of failure on which your handler is called using:

 
 uni.onFailure(IOException.class).recoverWithItem("boom")
 uni.onFailure(IllegalStateException.class).recoverWithItem("kaboom")
 uni.onFailure(t -> accept(t)).recoverWithItem("another boom")
 
 

Constructor Summary

Constructors

Constructor and Description
UniOnFailure(Uni<T> upstream, Predicate<? super Throwable> predicate)

Method Summary

Modifier and Type	Method and Description
Uni<T>	apply(Function<? super Throwable,? extends Throwable> mapper) Deprecated. use transform(Function)
Uni<T>	invoke(Consumer<Throwable> callback) Produces a new Uni invoking the given callback when this Uni emits a failure (matching the predicate if set).
Uni<T>	invokeUni(Function<Throwable,? extends Uni<?>> action) Produces a new Uni invoking the given function when the current Uni propagates a failure (matching the predicate if set).
Uni<T>	recoverWithItem(Function<? super Throwable,? extends T> function) Recovers from the received failure (matching the predicate if set) by using a item generated by the given function.
Uni<T>	recoverWithItem(Supplier<T> supplier) Recovers from the received failure (matching the predicate if set) by using a item generated by the given supplier.
Uni<T>	recoverWithItem(T fallback) Recovers from the received failure (matching the predicate if set) by using a fallback item.
Uni<T>	recoverWithUni(Function<? super Throwable,? extends Uni<? extends T>> function) Recovers from the received failure (matching the predicate if set) with another Uni.
Uni<T>	recoverWithUni(Supplier<? extends Uni<? extends T>> supplier) Recovers from the received failure (matching the predicate if set) with another Uni.
Uni<T>	recoverWithUni(Uni<? extends T> fallback) Recovers from the received failure (matching the predicate if set) with another Uni.
UniRetry<T>	retry() Configures the retry strategy.
Uni<T>	transform(Function<? super Throwable,? extends Throwable> mapper) Produces a new Uni invoking the given function when the current Uni propagates a failure.

Methods inherited from class java.lang.Object

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

Constructor Detail

UniOnFailure

public UniOnFailure(Uni<T> upstream,
                    Predicate<? super Throwable> predicate)

Method Detail

invoke

public Uni<T> invoke(Consumer<Throwable> callback)

Produces a new Uni invoking the given callback when this Uni emits a failure (matching the predicate if set).

If the callback throws an exception, a CompositeException is propagated downstream. This exception is composed by the received failure and the thrown exception.

Parameters:

callback - the callback, must not be null

Returns:

the new Uni

invokeUni

public Uni<T> invokeUni(Function<Throwable,? extends Uni<?>> action)

Produces a new Uni invoking the given function when the current Uni propagates a failure (matching the predicate if set). The function can transform the received failure into another exception that will be fired as failure downstream. Produces a new Uni invoking the given @{code action} when the failure event is received.

Unlike invoke(Consumer), the passed function returns a Uni. When the produced Uni sends its item, this item is discarded, and the original failure is forwarded downstream. If the produced Uni fails, a composite failure containing both the original failure and the failure from the executed action is propagated downstream.

Parameters:

action - the callback, must not be null

Returns:

the new Uni

apply

@Deprecated
public Uni<T> apply(Function<? super Throwable,? extends Throwable> mapper)

Deprecated. use transform(Function)

Produces a new Uni invoking the given function when the current Uni propagates a failure. The function can transform the received failure into another exception that will be fired as failure downstream.

Parameters:

mapper - the mapper function, must not be null, must not return null

Returns:

the new Uni

transform

public Uni<T> transform(Function<? super Throwable,? extends Throwable> mapper)

Produces a new Uni invoking the given function when the current Uni propagates a failure. The function can transform the received failure into another exception that will be fired as failure downstream.

Parameters:

mapper - the mapper function, must not be null, must not return null

Returns:

the new Uni

recoverWithItem

public Uni<T> recoverWithItem(T fallback)

Recovers from the received failure (matching the predicate if set) by using a fallback item.

Parameters:

fallback - the fallback, can be null

Returns:

the new Uni that would emit the given fallback in case the upstream sends us a failure.

recoverWithItem

public Uni<T> recoverWithItem(Supplier<T> supplier)

Recovers from the received failure (matching the predicate if set) by using a item generated by the given supplier. The supplier is called when the failure is received.

If the supplier throws an exception, a CompositeException containing both the received failure and the thrown exception is propagated downstream.

Parameters:

supplier - the supplier providing the fallback item. Must not be null, can return null.

Returns:

the new Uni that would emit the produced item in case the upstream sends a failure.

recoverWithItem

public Uni<T> recoverWithItem(Function<? super Throwable,? extends T> function)

Recovers from the received failure (matching the predicate if set) by using a item generated by the given function. The function is called when the failure is received.

If the function throws an exception, a CompositeException containing both the received failure and the thrown exception is propagated downstream.

Parameters:

function - the function providing the fallback item. Must not be null, can return null.

Returns:

the new Uni that would emit the produced item in case the upstream sends a failure.

recoverWithUni

public Uni<T> recoverWithUni(Function<? super Throwable,? extends Uni<? extends T>> function)

Recovers from the received failure (matching the predicate if set) with another Uni. This uni is produced by the given function. This uni can emit an item (potentially null or a failure. The function must not return null.

If the function throws an exception, a CompositeException containing both the received failure and the thrown exception is propagated downstream.

Parameters:

function - the function providing the fallback uni. Must not be null, must not return null.

Returns:

the new Uni that would emit events from the uni produced by the given function in case the upstream sends a failure.

recoverWithUni

public Uni<T> recoverWithUni(Supplier<? extends Uni<? extends T>> supplier)

Recovers from the received failure (matching the predicate if set) with another Uni. This uni is produced by the given supplier. This uni can emit an item (potentially null or a failure. The supplier must not return null.

If the supplier throws an exception, a CompositeException containing both the received failure and the thrown exception is propagated downstream.

Parameters:

supplier - the supplier providing the fallback uni. Must not be null, must not return null.

Returns:

the new Uni that would emits events from the uni produced by the given supplier in case the upstream sends a failure.

recoverWithUni

public Uni<T> recoverWithUni(Uni<? extends T> fallback)

Recovers from the received failure (matching the predicate if set) with another Uni. This uni can emit an item (potentially null or a failure.

Parameters:

fallback - the fallbakc uni, must not be null

Returns:

the new Uni that would emit events from the uni in case the upstream sends a failure.

retry

public UniRetry<T> retry()

Configures the retry strategy.

Returns:

the object to configure the retry.