Use named virtual threads for Jetty

Closes gh-40152

Author: mhalbritter

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/embedded/JettyVirtualThreadsWebServerFactoryCustomizer.java

@@ -44,7 +44,7 @@ public JettyVirtualThreadsWebServerFactoryCustomizer(ServerProperties serverProp
 	public void customize(ConfigurableJettyWebServerFactory factory) {
 		Assert.state(VirtualThreads.areSupported(), "Virtual threads are not supported");
 		QueuedThreadPool threadPool = JettyThreadPool.create(this.serverProperties.getJetty().getThreads());
-		threadPool.setVirtualThreadsExecutor(VirtualThreads.getDefaultVirtualThreadsExecutor());
+		threadPool.setVirtualThreadsExecutor(VirtualThreads.getNamedVirtualThreadsExecutor("jetty-"));
 		factory.setThreadPool(threadPool);
 	}
 

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/embedded/JettyVirtualThreadsWebServerFactoryCustomizerTests.java

@@ -16,7 +16,13 @@
 
 package org.springframework.boot.autoconfigure.web.embedded;
 
+import java.time.Duration;
+import java.util.concurrent.Executor;
+import java.util.concurrent.atomic.AtomicReference;
+
+import org.awaitility.Awaitility;
 import org.eclipse.jetty.util.thread.QueuedThreadPool;
+import org.hamcrest.Matchers;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.condition.EnabledForJreRange;
 import org.junit.jupiter.api.condition.JRE;
@@ -47,7 +53,12 @@ void shouldConfigureVirtualThreads() {
 		then(factory).should().setThreadPool(assertArg((threadPool) -> {
 			assertThat(threadPool).isInstanceOf(QueuedThreadPool.class);
 			QueuedThreadPool queuedThreadPool = (QueuedThreadPool) threadPool;
-			assertThat(queuedThreadPool.getVirtualThreadsExecutor()).isNotNull();
+			Executor executor = queuedThreadPool.getVirtualThreadsExecutor();
+			assertThat(executor).isNotNull();
+			AtomicReference<String> threadName = new AtomicReference<>();
+			executor.execute(() -> threadName.set(Thread.currentThread().getName()));
+			Awaitility.await().atMost(Duration.ofSeconds(1)).untilAtomic(threadName, Matchers.notNullValue());
+			assertThat(threadName.get()).startsWith("jetty-");
 		}));
 	}