Add support for Jetty Reactive Streams HTTP client

Leverage https://github.com/jetty-project/jetty-reactive-httpclient
to add support for Jetty in WebClient via JettyClientHttpConnector.

Implemented with buffer copy instead of optimized buffer wrapping
because the latter hangs since Callback#succeeded doesn't allow
releasing the buffer and requesting more data at different times
(required for Mono<DataBuffer> for example).
See https://github.com/eclipse/jetty.project/issues/2429.

Issue: SPR-15092

spring-webflux/src/test/java/org/springframework/web/reactive/function/client/WebClientIntegrationTests.java

@@ -32,6 +32,8 @@ import org.hamcrest.Matchers;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.Mono;
 import reactor.test.StepVerifier;
@@ -46,6 +48,9 @@ import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpStatus;
 import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
+import org.springframework.http.client.reactive.ClientHttpConnector;
+import org.springframework.http.client.reactive.JettyClientHttpConnector;
+import org.springframework.http.client.reactive.ReactorClientHttpConnector;
 import org.springframework.http.codec.Pojo;
 
 import static org.junit.Assert.*;
@@ -56,18 +61,35 @@ import static org.junit.Assert.*;
  * @author Brian Clozel
  * @author Rossen Stoyanchev
  * @author Denys Ivano
+ * @author Sebastien Deleuze
  */
+@RunWith(Parameterized.class)
 public class WebClientIntegrationTests {
 
 	private MockWebServer server;
 
 	private WebClient webClient;
 
+	@Parameterized.Parameter(0)
+	public ClientHttpConnector connector;
+
+	@Parameterized.Parameters(name = "webClient [{0}]")
+	public static Object[][] arguments() {
+
+		return new Object[][] {
+				{new JettyClientHttpConnector()},
+				{new ReactorClientHttpConnector()}
+		};
+	}
 
 	@Before
 	public void setup() {
 		this.server = new MockWebServer();
-		this.webClient = WebClient.create(this.server.url("/").toString());
+		this.webClient = WebClient
+				.builder()
+				.clientConnector(this.connector)
+				.baseUrl(this.server.url("/").toString())
+				.build();
 	}
 
 	@After
@@ -124,6 +146,28 @@ public class WebClientIntegrationTests {
 		});
 	}
 
+	@Test
+	public void shouldReceivePlainTextFlux() throws Exception {
+		prepareResponse(response -> response.setBody("Hello Spring!"));
+
+		Flux<String> result = this.webClient.get()
+				.uri("/greeting?name=Spring")
+				.header("X-Test-Header", "testvalue")
+				.exchange()
+				.flatMapMany(response -> response.bodyToFlux(String.class));
+
+		StepVerifier.create(result)
+				.expectNext("Hello Spring!")
+				.expectComplete().verify(Duration.ofSeconds(3));
+
+		expectRequestCount(1);
+		expectRequest(request -> {
+			assertEquals("testvalue", request.getHeader("X-Test-Header"));
+			assertEquals("*/*", request.getHeader(HttpHeaders.ACCEPT));
+			assertEquals("/greeting?name=Spring", request.getPath());
+		});
+	}
+
 	@Test
 	public void shouldReceiveJsonAsString() {
 		String content = "{\"bar\":\"barbar\",\"foo\":\"foofoo\"}";

spring-webflux/src/test/java/org/springframework/web/reactive/result/method/annotation/SseIntegrationTests.java

@@ -16,12 +16,14 @@
 
 package org.springframework.web.reactive.result.method.annotation;
 
+import java.io.File;
 import java.time.Duration;
 
 import org.junit.Assume;
 import org.junit.Before;
 import org.junit.Ignore;
 import org.junit.Test;
+import org.junit.runners.Parameterized;
 import reactor.core.publisher.Flux;
 import reactor.core.publisher.MonoProcessor;
 import reactor.test.StepVerifier;
@@ -30,11 +32,16 @@ import org.springframework.context.annotation.AnnotationConfigApplicationContext
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.ParameterizedTypeReference;
+import org.springframework.http.client.reactive.ClientHttpConnector;
+import org.springframework.http.client.reactive.JettyClientHttpConnector;
+import org.springframework.http.client.reactive.ReactorClientHttpConnector;
 import org.springframework.http.codec.ServerSentEvent;
 import org.springframework.http.server.reactive.AbstractHttpHandlerIntegrationTests;
 import org.springframework.http.server.reactive.HttpHandler;
 import org.springframework.http.server.reactive.bootstrap.JettyHttpServer;
 import org.springframework.http.server.reactive.bootstrap.ReactorHttpServer;
+import org.springframework.http.server.reactive.bootstrap.TomcatHttpServer;
+import org.springframework.http.server.reactive.bootstrap.UndertowHttpServer;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RestController;
@@ -56,12 +63,33 @@ public class SseIntegrationTests extends AbstractHttpHandlerIntegrationTests {
 
 	private WebClient webClient;
 
+	@Parameterized.Parameter(1)
+	public ClientHttpConnector connector;
+
+	@Parameterized.Parameters(name = "server [{0}] webClient [{1}]")
+	public static Object[][] arguments() {
+		File base = new File(System.getProperty("java.io.tmpdir"));
+		return new Object[][] {
+				{new JettyHttpServer(), new ReactorClientHttpConnector()},
+				{new JettyHttpServer(), new JettyClientHttpConnector()},
+				{new ReactorHttpServer(), new ReactorClientHttpConnector()},
+				{new ReactorHttpServer(), new JettyClientHttpConnector()},
+				{new TomcatHttpServer(base.getAbsolutePath()), new ReactorClientHttpConnector()},
+				{new TomcatHttpServer(base.getAbsolutePath()), new JettyClientHttpConnector()},
+				{new UndertowHttpServer(), new ReactorClientHttpConnector()},
+				{new UndertowHttpServer(), new JettyClientHttpConnector()}
+		};
+	}
 
 	@Override
 	@Before
 	public void setup() throws Exception {
 		super.setup();
-		this.webClient = WebClient.create("http://localhost:" + this.port + "/sse");
+		this.webClient = WebClient
+				.builder()
+				.clientConnector(this.connector)
+				.baseUrl("http://localhost:" + this.port + "/sse")
+				.build();
 	}