Improve FlushingIntegrationTests

spring-webflux/src/test/java/org/springframework/web/reactive/FlushingIntegrationTests.java

@@ -32,7 +32,6 @@ import org.springframework.http.server.reactive.AbstractHttpHandlerIntegrationTe
 import org.springframework.http.server.reactive.HttpHandler;
 import org.springframework.http.server.reactive.ServerHttpRequest;
 import org.springframework.http.server.reactive.ServerHttpResponse;
-import org.springframework.web.reactive.function.BodyExtractors;
 import org.springframework.web.reactive.function.client.WebClient;
 
 import static org.junit.Assert.assertTrue;
@@ -57,8 +56,8 @@ public class FlushingIntegrationTests extends AbstractHttpHandlerIntegrationTest
 	public void writeAndFlushWith() throws Exception {
 		Mono<String> result = this.webClient.get()
 				.uri("/write-and-flush")
-				.exchange()
+				.retrieve()
-				.flatMapMany(response -> response.body(BodyExtractors.toFlux(String.class)))
+				.bodyToFlux(String.class)
 				.takeUntil(s -> s.endsWith("data1"))
 				.reduce((s1, s2) -> s1 + s2);
 
@@ -72,13 +71,13 @@ public class FlushingIntegrationTests extends AbstractHttpHandlerIntegrationTest
 	public void writeAndAutoFlushOnComplete() {
 		Mono<String> result = this.webClient.get()
 				.uri("/write-and-complete")
-				.exchange()
+				.retrieve()
-				.flatMapMany(response -> response.bodyToFlux(String.class))
+				.bodyToFlux(String.class)
 				.reduce((s1, s2) -> s1 + s2);
 
 		try {
 			StepVerifier.create(result)
-					.consumeNextWith(value -> assertTrue(value.length() == 200000))
+					.consumeNextWith(value -> assertTrue(value.length() == 20000 * "0123456789".length()))
 					.expectComplete()
 					.verify(Duration.ofSeconds(5L));
 		}
@@ -95,14 +94,15 @@ public class FlushingIntegrationTests extends AbstractHttpHandlerIntegrationTest
 
 	@Test  // SPR-14992
 	public void writeAndAutoFlushBeforeComplete() {
-		Flux<String> result = this.webClient.get()
+		Mono<String> result = this.webClient.get()
 				.uri("/write-and-never-complete")
-				.exchange()
+				.retrieve()
-				.flatMapMany(response -> response.bodyToFlux(String.class));
+				.bodyToFlux(String.class)
+				.next();
 
 		StepVerifier.create(result)
 				.expectNextMatches(s -> s.startsWith("0123456789"))
-				.thenCancel()
+				.expectComplete()
 				.verify(Duration.ofSeconds(5L));
 	}