How to implement guide with java 17 completablefuture not returning expected result in http request handling
I'm converting an old project and I've searched everywhere and can't find a clear answer... I can't seem to get I just started working with I'm working with an scenario with using `CompletableFuture` in Java 17 while trying to handle multiple HTTP requests asynchronously... I have a method that fetches data from an external API and I want to wait for all requests to complete before processing the results. However, I'm working with an unexpected behavior where the results are not as expected. Here's the code snippet I'm using: ```java import java.net.HttpURLConnection; import java.net.URL; import java.util.concurrent.CompletableFuture; import java.util.List; public class ApiDataFetcher { public CompletableFuture<String> fetchData(String endpoint) { return CompletableFuture.supplyAsync(() -> { try { URL url = new URL(endpoint); HttpURLConnection conn = (HttpURLConnection) url.openConnection(); conn.setRequestMethod("GET"); int responseCode = conn.getResponseCode(); if (responseCode == 200) { // Logic to read and return response return "Success"; // Placeholder for actual response } else { return "behavior"; } } catch (Exception e) { e.printStackTrace(); return "Exception"; } }); } public void fetchDataFromMultipleEndpoints(List<String> endpoints) { CompletableFuture[] futures = endpoints.stream() .map(this::fetchData) .toArray(CompletableFuture[]::new); CompletableFuture<Void> allOf = CompletableFuture.allOf(futures); allOf.join(); // Wait for all to complete // Process results here - this is where I have trouble } } ``` When I call `fetchDataFromMultipleEndpoints(List.of("http://api1.com", "http://api2.com"));`, it seems to run all requests concurrently, but when I process the results afterward, I'm only receiving the last result instead of an aggregate of all responses. I've tried using `thenApply` to collect the results, but still, I don’t get the combined results as expected. The printed output shows only the last response. What am I doing wrong? Should I be using a different approach to gather the results from these futures? Any insights would be appreciated! What's the best practice here? Thanks for taking the time to read this! For context: I'm using Java on Windows 10. What would be the recommended way to handle this? This issue appeared after updating to Java 3.9. Is there a simpler solution I'm overlooking? What am I doing wrong?