CircuitBreaker.decorateSupplier catches Exception but Supplier can only throw RuntimeException

Resilience4j version: 1.5.0

Java version: 1.11

Thanks for raising a Resilience4j issue.

I see that we catch a general Exception from supplier.get() & publish an Error event. But Supplier only throws RuntimeExceptions.

If the Supplier can only throw RuntimeException, why not catch RuntimeException and be explicit?

https://github.com/resilience4j/resilience4j/blob/7fe040e1bf852ccaaaa8317448a8e6fce0202373/resilience4j-circuitbreaker/src/main/java/io/github/resilience4j/circuitbreaker/CircuitBreaker.java#L201

    static <T> Supplier<T> decorateSupplier(CircuitBreaker circuitBreaker, Supplier<T> supplier) {
        return () -> {
            circuitBreaker.acquirePermission();
            final long start = circuitBreaker.getCurrentTimestamp();
            try {
                T result = supplier.get();
                long duration = circuitBreaker.getCurrentTimestamp() - start;
                circuitBreaker.onResult(duration, circuitBreaker.getTimestampUnit(), result);
                return result;
            } catch (Exception exception) {
                // Do not handle java.lang.Error
                long duration = circuitBreaker.getCurrentTimestamp() - start;
                circuitBreaker.onError(duration, circuitBreaker.getTimestampUnit(), exception);
                throw exception;
            }
        };
    }

[RobWin]

Yes, you can use

circuitbreakerConfig.recordException(ex -> ex.getCause() instanceof YourException)

retryConfig.retryOnException(ex -> ex.getCause() instanceof YourException)

[asthinasthi]

We have an internal ThrowingSupplier which is a wrapper around Supplier to allow checked exception in the lambda expressions. We sneakyThrow Exceptions as RuntimeExceptions.

We were using recordExceptions list & assuming that retry would work for Suppliers. 🤦 My Bad.

This is just an observation that we could catch only RuntimeExceptions because Suppliers can only throw RuntimeException.

@RobWin Is there a way to use recordExceptions to retry on cause instead of actual exception. We are wrapping our Checked Exceptions and throwing RuntimExceptions in our ThrowingSupplier

Is using CheckedFunction only way to make the Retry work on recordExceptions ?

Also, I can’t seem to find a Decorator for CheckedSupplier for ThreadpoolBulkhead. #1307