JEP 517: HTTP/3 for the HTTP Client API

Author: ibrahimatay

README.md

@@ -11,6 +11,7 @@ This repository contains Java examples that are designed to track and document t
 ## Specifications & Practices
 
 * [Java 26](java-26/) (March, 2026)
+    * [JEP 517](java-26/src/main/java/JEP517HTTP3ForTheHTTPClientAPI.java): HTTP/3 for the HTTP Client API
     * [JEP 500](java-26/src/main/java/JEP500PrepareToMakeFinalMeanFinal.java): Prepare to Make Final Mean Final
 * [Java 25](java-25/) (September, 2025)
   * [JEP 513](java-25/src/main/java/JEP513FlexibleConstructorBodies.java): Flexible Constructor Bodies

java-26/src/main/java/JEP517HTTP3ForTheHTTPClientAPI.java

@@ -0,0 +1,36 @@
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.net.http.HttpClient.Version;
+
+public class JEP517HTTP3ForTheHTTPClientAPI {
+    static void main() {
+        try {
+            // 1. Configure the HttpClient to prefer HTTP/3
+            // If the server does not support HTTP/3, it will automatically fallback to HTTP/2
+            HttpClient client = HttpClient.newBuilder()
+                    .version(Version.HTTP_3)
+                    .build();
+
+            // 2. Create the request for an HTTP/3 enabled endpoint
+            HttpRequest request = HttpRequest.newBuilder()
+                    .uri(URI.create("https://quic.rocks:4433/"))
+                    .GET()
+                    .build();
+
+            // 3. Send the request and receive the response synchronously
+            HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString());
+
+            // 4. Output the results to the console
+            System.out.println("Protocol Used: " + response.version());
+            System.out.println("Status Code: " + response.statusCode());
+            System.out.println("Response Body (Preview): " + response.body().substring(0, 100) + "...");
+
+        } catch (Exception e) {
+            // Handle potential network or protocol exceptions
+            System.err.println("Error during HTTP/3 request: " + e.getMessage());
+            e.printStackTrace();
+        }
+    }
+}