Merge pull request #46404 from smartandhandsome

* pr/46404:
  Polish 'Support virtual threading with JDK HTTP clients'
  Support virtual threading with JDK HTTP clients

Closes gh-46404

Author: philwebb

module/spring-boot-http-client/src/main/java/org/springframework/boot/http/client/JdkClientHttpRequestFactoryBuilder.java

@@ -19,6 +19,7 @@
 import java.net.http.HttpClient;
 import java.util.Collection;
 import java.util.List;
+import java.util.concurrent.Executor;
 import java.util.function.Consumer;
 
 import org.jspecify.annotations.Nullable;
@@ -34,6 +35,7 @@
  * @author Phillip Webb
  * @author Andy Wilkinson
  * @author Scott Frederick
+ * @author Sangmin Park
  * @since 3.4.0
  */
 public final class JdkClientHttpRequestFactoryBuilder
@@ -62,6 +64,17 @@ public JdkClientHttpRequestFactoryBuilder withCustomizers(
 		return new JdkClientHttpRequestFactoryBuilder(mergedCustomizers(customizers), this.httpClientBuilder);
 	}
 
+	/**
+	 * Return a new {@link JdkClientHttpRequestFactoryBuilder} uses the given executor
+	 * with the underlying {@link java.net.http.HttpClient.Builder}.
+	 * @param executor the executor to use
+	 * @return a new {@link JdkClientHttpRequestFactoryBuilder} instance
+	 * @since 4.0.0
+	 */
+	public JdkClientHttpRequestFactoryBuilder withExecutor(Executor executor) {
+		return new JdkClientHttpRequestFactoryBuilder(getCustomizers(), this.httpClientBuilder.withExecutor(executor));
+	}
+
 	/**
 	 * Return a new {@link JdkClientHttpRequestFactoryBuilder} that applies additional
 	 * customization to the underlying {@link java.net.http.HttpClient.Builder}.

module/spring-boot-http-client/src/main/java/org/springframework/boot/http/client/JdkHttpClientBuilder.java

@@ -18,6 +18,7 @@
 
 import java.net.http.HttpClient;
 import java.net.http.HttpClient.Redirect;
+import java.util.concurrent.Executor;
 import java.util.function.Consumer;
 
 import javax.net.ssl.SSLParameters;
@@ -49,6 +50,18 @@ private JdkHttpClientBuilder(Consumer<HttpClient.Builder> customizer) {
 		this.customizer = customizer;
 	}
 
+	/**
+	 * Return a new {@link JdkHttpClientBuilder} uses the given executor with the
+	 * underlying {@link java.net.http.HttpClient.Builder}.
+	 * @param executor the executor to use
+	 * @return a new {@link JdkHttpClientBuilder} instance
+	 * @since 4.0.0
+	 */
+	public JdkHttpClientBuilder withExecutor(Executor executor) {
+		Assert.notNull(executor, "'executor' must not be null");
+		return withCustomizer((httpClient) -> httpClient.executor(executor));
+	}
+
 	/**
 	 * Return a new {@link JdkHttpClientBuilder} that applies additional customization to
 	 * the underlying {@link java.net.http.HttpClient.Builder}.

module/spring-boot-http-client/src/main/java/org/springframework/boot/http/client/autoconfigure/HttpClientAutoConfiguration.java

@@ -28,17 +28,22 @@
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.boot.http.client.ClientHttpRequestFactoryBuilder;
 import org.springframework.boot.http.client.ClientHttpRequestFactorySettings;
+import org.springframework.boot.http.client.JdkClientHttpRequestFactoryBuilder;
 import org.springframework.boot.ssl.SslBundles;
+import org.springframework.boot.thread.Threading;
 import org.springframework.boot.util.LambdaSafe;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Conditional;
+import org.springframework.core.env.Environment;
+import org.springframework.core.task.VirtualThreadTaskExecutor;
 import org.springframework.http.client.ClientHttpRequestFactory;
 
 /**
  * {@link EnableAutoConfiguration Auto-configuration} for
  * {@link ClientHttpRequestFactoryBuilder} and {@link ClientHttpRequestFactorySettings}.
  *
  * @author Phillip Webb
+ * @author Sangmin Park
  * @since 4.0.0
  */
 @SuppressWarnings("removal")
@@ -50,10 +55,14 @@ public final class HttpClientAutoConfiguration implements BeanClassLoaderAware {
 
 	private final ClientHttpRequestFactories factories;
 
+	private final Environment environment;
+
 	@SuppressWarnings("NullAway.Init")
 	private ClassLoader beanClassLoader;
 
-	HttpClientAutoConfiguration(ObjectProvider<SslBundles> sslBundles, HttpClientProperties properties) {
+	HttpClientAutoConfiguration(Environment environment, ObjectProvider<SslBundles> sslBundles,
+			HttpClientProperties properties) {
+		this.environment = environment;
 		this.factories = new ClientHttpRequestFactories(sslBundles, properties);
 	}
 
@@ -64,9 +73,12 @@ public void setBeanClassLoader(ClassLoader classLoader) {
 
 	@Bean
 	@ConditionalOnMissingBean
-	ClientHttpRequestFactoryBuilder<?> clientHttpRequestFactoryBuilder(
+	ClientHttpRequestFactoryBuilder<?> clientHttpRequestFactoryBuilderOnPlatform(
 			ObjectProvider<ClientHttpRequestFactoryBuilderCustomizer<?>> clientHttpRequestFactoryBuilderCustomizers) {
 		ClientHttpRequestFactoryBuilder<?> builder = this.factories.builder(this.beanClassLoader);
+		if (builder instanceof JdkClientHttpRequestFactoryBuilder jdk && Threading.VIRTUAL.isActive(this.environment)) {
+			builder = jdk.withExecutor(new VirtualThreadTaskExecutor("httpclient-"));
+		}
 		return customize(builder, clientHttpRequestFactoryBuilderCustomizers.orderedStream().toList());
 	}
 

module/spring-boot-http-client/src/main/java/org/springframework/boot/http/client/autoconfigure/reactive/ClientHttpConnectorAutoConfiguration.java

@@ -30,16 +30,20 @@
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.boot.http.client.reactive.ClientHttpConnectorBuilder;
 import org.springframework.boot.http.client.reactive.ClientHttpConnectorSettings;
+import org.springframework.boot.http.client.reactive.JdkClientHttpConnectorBuilder;
 import org.springframework.boot.http.client.reactive.ReactorClientHttpConnectorBuilder;
 import org.springframework.boot.reactor.netty.autoconfigure.ReactorNettyConfigurations;
 import org.springframework.boot.ssl.SslBundles;
+import org.springframework.boot.thread.Threading;
 import org.springframework.boot.util.LambdaSafe;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Conditional;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Import;
 import org.springframework.context.annotation.Lazy;
 import org.springframework.core.annotation.Order;
+import org.springframework.core.env.Environment;
+import org.springframework.core.task.VirtualThreadTaskExecutor;
 import org.springframework.http.client.ReactorResourceFactory;
 import org.springframework.http.client.reactive.ClientHttpConnector;
 
@@ -58,11 +62,14 @@ public final class ClientHttpConnectorAutoConfiguration implements BeanClassLoad
 
 	private final ClientHttpConnectors connectors;
 
+	private final Environment environment;
+
 	@SuppressWarnings("NullAway.Init")
 	private ClassLoader beanClassLoader;
 
-	ClientHttpConnectorAutoConfiguration(ObjectProvider<SslBundles> sslBundles,
+	ClientHttpConnectorAutoConfiguration(Environment environment, ObjectProvider<SslBundles> sslBundles,
 			HttpReactiveClientProperties properties) {
+		this.environment = environment;
 		this.connectors = new ClientHttpConnectors(sslBundles, properties);
 	}
 
@@ -76,6 +83,9 @@ public void setBeanClassLoader(ClassLoader classLoader) {
 	ClientHttpConnectorBuilder<?> clientHttpConnectorBuilder(
 			ObjectProvider<ClientHttpConnectorBuilderCustomizer<?>> clientHttpConnectorBuilderCustomizers) {
 		ClientHttpConnectorBuilder<?> builder = this.connectors.builder(this.beanClassLoader);
+		if (builder instanceof JdkClientHttpConnectorBuilder jdk && Threading.VIRTUAL.isActive(this.environment)) {
+			builder = jdk.withExecutor(new VirtualThreadTaskExecutor("httpclient-"));
+		}
 		return customize(builder, clientHttpConnectorBuilderCustomizers.orderedStream().toList());
 	}
 

module/spring-boot-http-client/src/main/java/org/springframework/boot/http/client/reactive/JdkClientHttpConnectorBuilder.java

@@ -19,6 +19,7 @@
 import java.net.http.HttpClient;
 import java.util.Collection;
 import java.util.List;
+import java.util.concurrent.Executor;
 import java.util.function.Consumer;
 
 import org.jspecify.annotations.Nullable;
@@ -59,6 +60,17 @@ public JdkClientHttpConnectorBuilder withCustomizers(Collection<Consumer<JdkClie
 		return new JdkClientHttpConnectorBuilder(mergedCustomizers(customizers), this.httpClientBuilder);
 	}
 
+	/**
+	 * Return a new {@link JdkClientHttpConnectorBuilder} uses the given executor with the
+	 * underlying {@link java.net.http.HttpClient.Builder}.
+	 * @param executor the executor to use
+	 * @return a new {@link JdkClientHttpConnectorBuilder} instance
+	 * @since 4.0.0
+	 */
+	public JdkClientHttpConnectorBuilder withExecutor(Executor executor) {
+		return new JdkClientHttpConnectorBuilder(getCustomizers(), this.httpClientBuilder.withExecutor(executor));
+	}
+
 	/**
 	 * Return a new {@link JdkClientHttpConnectorBuilder} that applies additional
 	 * customization to the underlying {@link java.net.http.HttpClient.Builder}.

module/spring-boot-http-client/src/test/java/org/springframework/boot/http/client/JdkClientHttpRequestFactoryBuilderTests.java

@@ -18,12 +18,16 @@
 
 import java.net.http.HttpClient;
 import java.time.Duration;
+import java.util.concurrent.Executor;
 
 import org.junit.jupiter.api.Test;
 
+import org.springframework.core.task.SimpleAsyncTaskExecutor;
 import org.springframework.http.client.JdkClientHttpRequestFactory;
 import org.springframework.test.util.ReflectionTestUtils;
 
+import static org.assertj.core.api.Assertions.assertThat;
+
 /**
  * Tests for {@link JdkClientHttpRequestFactoryBuilder} and {@link JdkHttpClientBuilder}.
  *
@@ -48,6 +52,14 @@ void withCustomizers() {
 		httpClientCustomizer2.assertCalled();
 	}
 
+	@Test
+	void withExecutor() {
+		Executor executor = new SimpleAsyncTaskExecutor();
+		JdkClientHttpRequestFactory factory = ClientHttpRequestFactoryBuilder.jdk().withExecutor(executor).build();
+		HttpClient httpClient = (HttpClient) ReflectionTestUtils.getField(factory, "httpClient");
+		assertThat(httpClient.executor()).containsSame(executor);
+	}
+
 	@Override
 	protected long connectTimeout(JdkClientHttpRequestFactory requestFactory) {
 		HttpClient httpClient = (HttpClient) ReflectionTestUtils.getField(requestFactory, "httpClient");

module/spring-boot-http-client/src/test/java/org/springframework/boot/http/client/autoconfigure/HttpClientAutoConfigurationTests.java

@@ -16,11 +16,14 @@
 
 package org.springframework.boot.http.client.autoconfigure;
 
+import java.net.http.HttpClient;
 import java.time.Duration;
 import java.util.ArrayList;
 import java.util.List;
 
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.EnabledForJreRange;
+import org.junit.jupiter.api.condition.JRE;
 
 import org.springframework.boot.autoconfigure.AutoConfigurations;
 import org.springframework.boot.autoconfigure.ssl.SslAutoConfiguration;
@@ -37,7 +40,9 @@
 import org.springframework.boot.test.context.runner.ReactiveWebApplicationContextRunner;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.core.task.VirtualThreadTaskExecutor;
 import org.springframework.http.client.ClientHttpRequestFactory;
+import org.springframework.test.util.ReflectionTestUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -146,6 +151,17 @@ void clientHttpRequestFactoryBuilderCustomizersAreApplied() {
 			});
 	}
 
+	@Test
+	@EnabledForJreRange(min = JRE.JAVA_21)
+	void whenVirtualThreadsEnabledAndUsingJdkHttpClientUsesVirtualThreadExecutor() {
+		this.contextRunner.withPropertyValues("spring.http.client.factory=jdk", "spring.threads.virtual.enabled=true")
+			.run((context) -> {
+				ClientHttpRequestFactory factory = context.getBean(ClientHttpRequestFactoryBuilder.class).build();
+				HttpClient httpClient = (HttpClient) ReflectionTestUtils.getField(factory, "httpClient");
+				assertThat(httpClient.executor().get()).isInstanceOf(VirtualThreadTaskExecutor.class);
+			});
+	}
+
 	@Configuration(proxyBeanMethods = false)
 	static class ClientHttpRequestFactoryBuilderCustomizersConfiguration {
 

module/spring-boot-http-client/src/test/java/org/springframework/boot/http/client/autoconfigure/reactive/ClientHttpConnectorAutoConfigurationTests.java

@@ -22,6 +22,8 @@
 
 import org.apache.hc.client5.http.impl.async.HttpAsyncClients;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.EnabledForJreRange;
+import org.junit.jupiter.api.condition.JRE;
 import reactor.netty.http.client.HttpClient;
 import reactor.netty.resources.LoopResources;
 
@@ -38,8 +40,10 @@
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
+import org.springframework.core.task.VirtualThreadTaskExecutor;
 import org.springframework.http.client.ReactorResourceFactory;
 import org.springframework.http.client.reactive.ClientHttpConnector;
+import org.springframework.test.util.ReflectionTestUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatIllegalStateException;
@@ -171,6 +175,19 @@ void shouldBeConditionalOnAtLeastOneHttpConnectorClass() {
 			.run((context) -> assertThat(context).doesNotHaveBean(ClientHttpConnectorSettings.class));
 	}
 
+	@Test
+	@EnabledForJreRange(min = JRE.JAVA_21)
+	void whenVirtualThreadsEnabledAndUsingJdkHttpClientUsesVirtualThreadExecutor() {
+		this.contextRunner
+			.withPropertyValues("spring.http.reactiveclient.connector=jdk", "spring.threads.virtual.enabled=true")
+			.run((context) -> {
+				ClientHttpConnector connector = context.getBean(ClientHttpConnectorBuilder.class).build();
+				java.net.http.HttpClient httpClient = (java.net.http.HttpClient) ReflectionTestUtils.getField(connector,
+						"httpClient");
+				assertThat(httpClient.executor().get()).isInstanceOf(VirtualThreadTaskExecutor.class);
+			});
+	}
+
 	private List<String> sslPropertyValues() {
 		List<String> propertyValues = new ArrayList<>();
 		String location = "classpath:org/springframework/boot/autoconfigure/ssl/";

module/spring-boot-http-client/src/test/java/org/springframework/boot/http/client/reactive/JdkClientHttpConnectorBuilderTests.java

@@ -18,13 +18,17 @@
 
 import java.net.http.HttpClient;
 import java.time.Duration;
+import java.util.concurrent.Executor;
 
 import org.junit.jupiter.api.Test;
 
 import org.springframework.boot.http.client.JdkHttpClientBuilder;
+import org.springframework.core.task.SimpleAsyncTaskExecutor;
 import org.springframework.http.client.reactive.JdkClientHttpConnector;
 import org.springframework.test.util.ReflectionTestUtils;
 
+import static org.assertj.core.api.Assertions.assertThat;
+
 /**
  * Tests for {@link JdkClientHttpConnectorBuilder} and {@link JdkHttpClientBuilder}.
  *
@@ -48,6 +52,14 @@ void withCustomizers() {
 		httpClientCustomizer2.assertCalled();
 	}
 
+	@Test
+	void withExecutor() {
+		Executor executor = new SimpleAsyncTaskExecutor();
+		JdkClientHttpConnector connector = ClientHttpConnectorBuilder.jdk().withExecutor(executor).build();
+		HttpClient httpClient = (HttpClient) ReflectionTestUtils.getField(connector, "httpClient");
+		assertThat(httpClient.executor()).containsSame(executor);
+	}
+
 	@Override
 	protected long connectTimeout(JdkClientHttpConnector connector) {
 		HttpClient httpClient = (HttpClient) ReflectionTestUtils.getField(connector, "httpClient");