Reactive programming with Java 8 and simple-react : error handling

simple-react provides three mechanisms to handle and recover from errors. They are :-

capture!

The capture operator allows unrecoverable errors to be handled or logged in some form

LazyFutureStream.sequentialBuilder()
                 .withRetrier(retrier)
                 .react(()->”new event1",()->”new event2")
                 .map(this::unreliable)
                 .capture(Throwable::printStackTrace)
                 .block();

retry!

The retry operator allows a failed task to be retried (up to configurable limits).

AsyncRetryExecutor retrier = new AsyncRetryExecutor(Executors.newScheduledThreadPool(Runtime.getRuntime().availableProcessors())).
 retryOn(Throwable.class).
 withMaxDelay(1_000). //1 seconds
 withUniformJitter(). //add between +/- 100 ms randomly
 withMaxRetries(5);
 
 LazyFutureStream.sequentialBuilder()
                 .withRetrier(retrier)
                 .react(()->”new event1",()->”new event2")
                 .retry(this::unreliable)
                 .capture(Throwable::printStackTrace)
                 .block();

onFail!

The onFail operator allows exceptions from a previous task to be dealt with.

 
 
 List<String> results = LazyFutureStream.sequentialBuilder()
                          .withRetrier(retrier)
                          .react(()->”new event1",()->”new event2")
                          .retry(this::unreliable)
                          .onFail(e->”default”)
                          .peek(System.out::println)
                          .capture(Throwable::printStackTrace)
                          .block();
 
 assertThat(results.size(),equalTo(2));

 
 
 
 
 private String unreliable(Object o) {
 throw new RuntimeException();
}

The Tutorial : Reactive programming with Java 8