Java 8 CompletableFuture with handling Handling: Unhandled ExecutionException in Nested Tasks
I'm experimenting with I just started working with I'm trying to use `CompletableFuture` in Java 8 to run multiple asynchronous tasks where each task depends on the result of the previous one... However, I'm running into an scenario where exceptions thrown in the nested futures are not being handled as I expected. Specifically, when a `CompletionException` occurs, I get an `ExecutionException` that I want to seem to unwrap properly. Here's the code I'm working with: ```java import java.util.concurrent.CompletableFuture; import java.util.concurrent.ExecutionException; public class CompletableFutureExample { public static void main(String[] args) { CompletableFuture.supplyAsync(() -> { // Simulate some computation if (true) throw new RuntimeException("behavior in first task"); return "First result"; }).thenApply(result -> { // This will never be executed due to exception in the first task return "Processed: " + result; }).exceptionally(ex -> { System.out.println("Caught exception: " + ex.getMessage()); return "Fallback result"; }); try { // Block and wait for the future to complete CompletableFuture.allOf(...).get(); } catch (ExecutionException e) { // This is where I'm struggling System.out.println("Unhandled ExecutionException: " + e.getMessage()); } catch (InterruptedException e) { Thread.currentThread().interrupt(); } } } ``` In the code, I am attempting to handle exceptions in the `CompletableFuture` chain using `exceptionally()`, but when I try to retrieve the result or wait for completion with `get()`, I run into an `ExecutionException`. It seems like I am not correctly managing the exception that bubbles up from the initial computation. Is there a way to ensure that exceptions are handled at each step without leading to unhandled exceptions? Additionally, is there a better practice for managing deeply nested asynchronous calls like this? Any insight would be appreciated! My team is using Java for this application. Any feedback is welcome!