diff --git a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/embedded/JettyWebServerFactoryCustomizer.java b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/embedded/JettyWebServerFactoryCustomizer.java
index 6f96a46cdc..af50cb5048 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/embedded/JettyWebServerFactoryCustomizer.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/web/embedded/JettyWebServerFactoryCustomizer.java
@@ -17,6 +17,7 @@
 package org.springframework.boot.autoconfigure.web.embedded;
 
 import java.time.Duration;
+import java.util.Arrays;
 
 import org.eclipse.jetty.server.AbstractConnector;
 import org.eclipse.jetty.server.ConnectionFactory;
@@ -76,8 +77,8 @@ public class JettyWebServerFactoryCustomizer implements
 				.to(factory::setSelectors);
 		propertyMapper.from(properties::getMaxHttpHeaderSize).whenNonNull()
 				.asInt(DataSize::toBytes).when(this::isPositive)
-				.to((maxHttpHeaderSize) -> customizeMaxHttpHeaderSize(factory,
-						maxHttpHeaderSize));
+				.to((maxHttpHeaderSize) -> factory.addServerCustomizers(
+						new MaxHttpHeaderSizeCustomizer(maxHttpHeaderSize)));
 		propertyMapper.from(jettyProperties::getMaxHttpPostSize).asInt(DataSize::toBytes)
 				.when(this::isPositive)
 				.to((maxHttpPostSize) -> customizeMaxHttpPostSize(factory,
@@ -115,32 +116,6 @@ public class JettyWebServerFactoryCustomizer implements
 		});
 	}
 
-	private void customizeMaxHttpHeaderSize(ConfigurableJettyWebServerFactory factory,
-			int maxHttpHeaderSize) {
-		factory.addServerCustomizers(new JettyServerCustomizer() {
-
-			@Override
-			public void customize(Server server) {
-				for (org.eclipse.jetty.server.Connector connector : server
-						.getConnectors()) {
-					for (ConnectionFactory connectionFactory : connector
-							.getConnectionFactories()) {
-						if (connectionFactory instanceof HttpConfiguration.ConnectionFactory) {
-							customize(
-									(HttpConfiguration.ConnectionFactory) connectionFactory);
-						}
-					}
-				}
-			}
-
-			private void customize(HttpConfiguration.ConnectionFactory factory) {
-				HttpConfiguration configuration = factory.getHttpConfiguration();
-				configuration.setRequestHeaderSize(maxHttpHeaderSize);
-			}
-
-		});
-	}
-
 	private void customizeMaxHttpPostSize(ConfigurableJettyWebServerFactory factory,
 			int maxHttpPostSize) {
 		factory.addServerCustomizers(new JettyServerCustomizer() {
@@ -199,4 +174,30 @@ public class JettyWebServerFactoryCustomizer implements
 		});
 	}
 
+	private static class MaxHttpHeaderSizeCustomizer implements JettyServerCustomizer {
+
+		private final int maxHttpHeaderSize;
+
+		MaxHttpHeaderSizeCustomizer(int maxHttpHeaderSize) {
+			this.maxHttpHeaderSize = maxHttpHeaderSize;
+		}
+
+		@Override
+		public void customize(Server server) {
+			Arrays.stream(server.getConnectors()).forEach(this::customize);
+		}
+
+		private void customize(org.eclipse.jetty.server.Connector connector) {
+			connector.getConnectionFactories().forEach(this::customize);
+		}
+
+		private void customize(ConnectionFactory factory) {
+			if (factory instanceof HttpConfiguration.ConnectionFactory) {
+				((HttpConfiguration.ConnectionFactory) factory).getHttpConfiguration()
+						.setRequestHeaderSize(this.maxHttpHeaderSize);
+			}
+		}
+
+	}
+
 }
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/jdbc/JdbcRepositoriesAutoConfigurationTests.java b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/jdbc/JdbcRepositoriesAutoConfigurationTests.java
index 2c897eb362..364dab9d25 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/jdbc/JdbcRepositoriesAutoConfigurationTests.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/jdbc/JdbcRepositoriesAutoConfigurationTests.java
@@ -51,10 +51,8 @@ public class JdbcRepositoriesAutoConfigurationTests {
 	@Test
 	public void backsOffWithNoDataSource() {
 		this.contextRunner.withUserConfiguration(TestConfiguration.class)
-				.run((context) -> {
-					assertThat(context)
-							.doesNotHaveBean(JdbcRepositoryConfigExtension.class);
-				});
+				.run((context) -> assertThat(context)
+						.doesNotHaveBean(JdbcRepositoryConfigExtension.class));
 	}
 
 	@Test
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/jsonb/JsonbAutoConfigurationWithNoProviderTests.java b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/jsonb/JsonbAutoConfigurationWithNoProviderTests.java
index b1c5a759da..11ec0dd88a 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/jsonb/JsonbAutoConfigurationWithNoProviderTests.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/jsonb/JsonbAutoConfigurationWithNoProviderTests.java
@@ -42,9 +42,8 @@ public class JsonbAutoConfigurationWithNoProviderTests {
 
 	@Test
 	public void jsonbBacksOffWhenThereIsNoProvider() {
-		this.contextRunner.run((context) -> {
-			assertThat(context).doesNotHaveBean(Jsonb.class);
-		});
+		this.contextRunner
+				.run((context) -> assertThat(context).doesNotHaveBean(Jsonb.class));
 	}
 
 }
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaAutoConfigurationTests.java b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaAutoConfigurationTests.java
index 54c0e6f82b..844ec4c8c7 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaAutoConfigurationTests.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaAutoConfigurationTests.java
@@ -592,9 +592,7 @@ public class HibernateJpaAutoConfigurationTests
 		@Bean
 		public EntityManagerFactoryBuilderCustomizer asyncBootstrappingCustomizer(
 				ThreadPoolTaskExecutor executor) {
-			return (builder) -> {
-				builder.setBootstrapExecutor(executor);
-			};
+			return (builder) -> builder.setBootstrapExecutor(executor);
 		}
 
 	}
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/embedded/TomcatWebServerFactoryCustomizerTests.java b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/embedded/TomcatWebServerFactoryCustomizerTests.java
index 6f8083fa8c..5f4b7615f1 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/embedded/TomcatWebServerFactoryCustomizerTests.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/embedded/TomcatWebServerFactoryCustomizerTests.java
@@ -73,12 +73,10 @@ public class TomcatWebServerFactoryCustomizerTests {
 
 	@Test
 	public void defaultsAreConsistent() {
-		customizeAndRunServer((server) -> {
-			assertThat(((AbstractHttp11Protocol<?>) server.getTomcat().getConnector()
-					.getProtocolHandler()).getMaxSwallowSize())
-							.isEqualTo(this.serverProperties.getTomcat()
-									.getMaxSwallowSize().toBytes());
-		});
+		customizeAndRunServer((server) -> assertThat(((AbstractHttp11Protocol<?>) server
+				.getTomcat().getConnector().getProtocolHandler()).getMaxSwallowSize())
+						.isEqualTo(this.serverProperties.getTomcat().getMaxSwallowSize()
+								.toBytes()));
 	}
 
 	@Test