implementing Using CompletableFuture and handling Handling in Java 11
I'm relatively new to this, so bear with me. I'm currently working on a Java application that leverages `CompletableFuture` for asynchronous tasks, and I've run into a question with exception handling. I have a method that fetches data from an external API, and I'm using `thenApply` to process the result. However, when the API call fails (for instance, throwing a `IOException`), the exception isn't being caught as I expect. Instead, it seems to propagate and cause the entire application to crash with the following behavior: `java.util.concurrent.CompletionException: java.io.IOException: Failed to fetch data`. Here's a simplified version of my code: ```java import java.util.concurrent.CompletableFuture; import java.io.IOException; public class AsyncService { public CompletableFuture<String> fetchData() { return CompletableFuture.supplyAsync(() -> { // Simulating API call if (Math.random() > 0.5) { throw new IOException("Failed to fetch data"); } return "Data fetched successfully"; }); } public void process() { fetchData() .thenApply(result -> { System.out.println(result); return result; }) .exceptionally(ex -> { System.err.println("behavior occurred: " + ex.getMessage()); return null; }); } } ``` In this implementation, I'm using `exceptionally` to handle any exceptions, but it seems like the `IOException` is being wrapped in a `CompletionException` and not handled properly. I’ve tried checking if the exception is an instance of `IOException` inside `exceptionally`, but it still doesn't give me the expected behavior. I am unsure how to ensure my application continues running and handles exceptions gracefully. Am I missing something in my approach to using `CompletableFuture`? Any advice or best practices for handling exceptions in this context would be greatly appreciated.