diff --git a/spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/metrics/mongo/MongoMetricsAutoConfigurationTests.java b/spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/metrics/mongo/MongoMetricsAutoConfigurationTests.java
index 8cd2eb6bfd..2e92c944cd 100644
--- a/spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/metrics/mongo/MongoMetricsAutoConfigurationTests.java
+++ b/spring-boot-project/spring-boot-actuator-autoconfigure/src/test/java/org/springframework/boot/actuate/autoconfigure/metrics/mongo/MongoMetricsAutoConfigurationTests.java
@@ -20,6 +20,7 @@ import java.util.List;
 
 import com.mongodb.MongoClientSettings;
 import com.mongodb.client.MongoClient;
+import com.mongodb.client.internal.MongoClientImpl;
 import com.mongodb.connection.ConnectionPoolSettings;
 import com.mongodb.event.ConnectionPoolListener;
 import io.micrometer.core.instrument.binder.mongodb.DefaultMongoCommandTagsProvider;
@@ -176,18 +177,15 @@ class MongoMetricsAutoConfigurationTests {
 
 	private MongoClientSettings getActualMongoClientSettingsUsedToConstructClient(
 			final AssertableApplicationContext context) {
-		final MongoClient mongoClient = context.getBean(MongoClient.class);
-		return (MongoClientSettings) ReflectionTestUtils.getField(mongoClient, "settings");
+		final MongoClientImpl mongoClient = (MongoClientImpl) context.getBean(MongoClient.class);
+		return mongoClient.getSettings();
 	}
 
 	private List<ConnectionPoolListener> getConnectionPoolListenersFromClient(
 			final AssertableApplicationContext context) {
 		MongoClientSettings mongoClientSettings = getActualMongoClientSettingsUsedToConstructClient(context);
 		ConnectionPoolSettings connectionPoolSettings = mongoClientSettings.getConnectionPoolSettings();
-		@SuppressWarnings("unchecked")
-		List<ConnectionPoolListener> listeners = (List<ConnectionPoolListener>) ReflectionTestUtils
-				.getField(connectionPoolSettings, "connectionPoolListeners");
-		return listeners;
+		return connectionPoolSettings.getConnectionPoolListeners();
 	}
 
 	private MongoCommandTagsProvider getMongoCommandTagsProviderUsedToConstructListener(
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/redis/RedisAutoConfigurationLettuceWithoutCommonsPool2Tests.java b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/redis/RedisAutoConfigurationLettuceWithoutCommonsPool2Tests.java
index 2e8c0d6481..54491ee294 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/redis/RedisAutoConfigurationLettuceWithoutCommonsPool2Tests.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/redis/RedisAutoConfigurationLettuceWithoutCommonsPool2Tests.java
@@ -23,7 +23,6 @@ import org.springframework.boot.test.context.runner.ApplicationContextRunner;
 import org.springframework.boot.testsupport.classpath.ClassPathExclusions;
 import org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory;
 import org.springframework.data.redis.connection.lettuce.LettucePoolingClientConfiguration;
-import org.springframework.test.util.ReflectionTestUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -43,8 +42,7 @@ public class RedisAutoConfigurationLettuceWithoutCommonsPool2Tests {
 		this.contextRunner.withPropertyValues("spring.redis.host:foo").run((context) -> {
 			LettuceConnectionFactory cf = context.getBean(LettuceConnectionFactory.class);
 			assertThat(cf.getHostName()).isEqualTo("foo");
-			assertThat(ReflectionTestUtils.getField(cf, "clientConfiguration"))
-					.isNotInstanceOf(LettucePoolingClientConfiguration.class);
+			assertThat(cf.getClientConfiguration()).isNotInstanceOf(LettucePoolingClientConfiguration.class);
 		});
 	}
 
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/redis/RedisAutoConfigurationTests.java b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/redis/RedisAutoConfigurationTests.java
index 0ff6c20939..38f87eb77d 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/redis/RedisAutoConfigurationTests.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/data/redis/RedisAutoConfigurationTests.java
@@ -207,8 +207,7 @@ class RedisAutoConfigurationTests {
 				.run((context) -> {
 					LettuceConnectionFactory cf = context.getBean(LettuceConnectionFactory.class);
 					assertThat(cf.getHostName()).isEqualTo("foo");
-					assertThat(ReflectionTestUtils.getField(cf, "clientConfiguration"))
-							.isNotInstanceOf(LettucePoolingClientConfiguration.class);
+					assertThat(cf.getClientConfiguration()).isNotInstanceOf(LettucePoolingClientConfiguration.class);
 				});
 	}
 
@@ -439,7 +438,7 @@ class RedisAutoConfigurationTests {
 	}
 
 	private LettucePoolingClientConfiguration getPoolingClientConfiguration(LettuceConnectionFactory factory) {
-		return (LettucePoolingClientConfiguration) ReflectionTestUtils.getField(factory, "clientConfiguration");
+		return (LettucePoolingClientConfiguration) factory.getClientConfiguration();
 	}
 
 	private String getUserName(LettuceConnectionFactory factory) {
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/http/HttpMessageConvertersTests.java b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/http/HttpMessageConvertersTests.java
index f8468fa85b..fb557cfc97 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/http/HttpMessageConvertersTests.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/http/HttpMessageConvertersTests.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2019 the original author or authors.
+ * Copyright 2012-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -33,7 +33,6 @@ import org.springframework.http.converter.smile.MappingJackson2SmileHttpMessageC
 import org.springframework.http.converter.support.AllEncompassingFormHttpMessageConverter;
 import org.springframework.http.converter.xml.MappingJackson2XmlHttpMessageConverter;
 import org.springframework.http.converter.xml.SourceHttpMessageConverter;
-import org.springframework.test.util.ReflectionTestUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.Mockito.mock;
@@ -143,10 +142,9 @@ class HttpMessageConvertersTests {
 				MappingJackson2HttpMessageConverter.class, MappingJackson2SmileHttpMessageConverter.class);
 	}
 
-	@SuppressWarnings("unchecked")
 	private List<HttpMessageConverter<?>> extractFormPartConverters(List<HttpMessageConverter<?>> converters) {
 		AllEncompassingFormHttpMessageConverter formConverter = findFormConverter(converters);
-		return (List<HttpMessageConverter<?>>) ReflectionTestUtils.getField(formConverter, "partConverters");
+		return formConverter.getPartConverters();
 	}
 
 	private AllEncompassingFormHttpMessageConverter findFormConverter(Collection<HttpMessageConverter<?>> converters) {
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mongo/MongoAutoConfigurationTests.java b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mongo/MongoAutoConfigurationTests.java
index e44f4cce13..b6ff9c5521 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mongo/MongoAutoConfigurationTests.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mongo/MongoAutoConfigurationTests.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,6 +21,7 @@ import java.util.concurrent.TimeUnit;
 import com.mongodb.MongoClientSettings;
 import com.mongodb.client.MongoClient;
 import com.mongodb.client.MongoClients;
+import com.mongodb.client.internal.MongoClientImpl;
 import org.junit.jupiter.api.Test;
 
 import org.springframework.boot.autoconfigure.AutoConfigurations;
@@ -28,7 +29,6 @@ import org.springframework.boot.test.context.assertj.AssertableApplicationContex
 import org.springframework.boot.test.context.runner.ApplicationContextRunner;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
-import org.springframework.test.util.ReflectionTestUtils;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -86,8 +86,8 @@ class MongoAutoConfigurationTests {
 
 	private MongoClientSettings getSettings(AssertableApplicationContext context) {
 		assertThat(context).hasSingleBean(MongoClient.class);
-		MongoClient client = context.getBean(MongoClient.class);
-		return (MongoClientSettings) ReflectionTestUtils.getField(client, "settings");
+		MongoClientImpl client = (MongoClientImpl) context.getBean(MongoClient.class);
+		return client.getSettings();
 	}
 
 	@Configuration(proxyBeanMethods = false)
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mongo/MongoClientFactoryTests.java b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mongo/MongoClientFactoryTests.java
index 7fbddedbcd..d793db83aa 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mongo/MongoClientFactoryTests.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mongo/MongoClientFactoryTests.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -20,8 +20,7 @@ import java.util.List;
 
 import com.mongodb.MongoClientSettings;
 import com.mongodb.client.MongoClient;
-
-import org.springframework.test.util.ReflectionTestUtils;
+import com.mongodb.client.internal.MongoClientImpl;
 
 /**
  * Tests for {@link MongoClientFactory}.
@@ -42,7 +41,7 @@ class MongoClientFactoryTests extends MongoClientFactorySupportTests<MongoClient
 
 	@Override
 	protected MongoClientSettings getClientSettings(MongoClient client) {
-		return (MongoClientSettings) ReflectionTestUtils.getField(client, "settings");
+		return ((MongoClientImpl) client).getSettings();
 	}
 
 }
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mongo/MongoReactiveAutoConfigurationTests.java b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mongo/MongoReactiveAutoConfigurationTests.java
index 90a659c92a..30ed753e99 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mongo/MongoReactiveAutoConfigurationTests.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mongo/MongoReactiveAutoConfigurationTests.java
@@ -26,6 +26,7 @@ import com.mongodb.connection.StreamFactory;
 import com.mongodb.connection.StreamFactoryFactory;
 import com.mongodb.connection.netty.NettyStreamFactoryFactory;
 import com.mongodb.reactivestreams.client.MongoClient;
+import com.mongodb.reactivestreams.client.internal.MongoClientImpl;
 import io.netty.channel.EventLoopGroup;
 import org.junit.jupiter.api.Test;
 
@@ -111,8 +112,8 @@ class MongoReactiveAutoConfigurationTests {
 	}
 
 	private MongoClientSettings getSettings(ApplicationContext context) {
-		MongoClient client = context.getBean(MongoClient.class);
-		return (MongoClientSettings) ReflectionTestUtils.getField(client, "settings");
+		MongoClientImpl client = (MongoClientImpl) context.getBean(MongoClient.class);
+		return client.getSettings();
 	}
 
 	@Configuration(proxyBeanMethods = false)
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mongo/ReactiveMongoClientFactoryTests.java b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mongo/ReactiveMongoClientFactoryTests.java
index 26c1639d02..c2b43d0e4c 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mongo/ReactiveMongoClientFactoryTests.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/mongo/ReactiveMongoClientFactoryTests.java
@@ -20,8 +20,7 @@ import java.util.List;
 
 import com.mongodb.MongoClientSettings;
 import com.mongodb.reactivestreams.client.MongoClient;
-
-import org.springframework.test.util.ReflectionTestUtils;
+import com.mongodb.reactivestreams.client.internal.MongoClientImpl;
 
 /**
  * Tests for {@link ReactiveMongoClientFactory}.
@@ -40,7 +39,7 @@ class ReactiveMongoClientFactoryTests extends MongoClientFactorySupportTests<Mon
 
 	@Override
 	protected MongoClientSettings getClientSettings(MongoClient client) {
-		return (MongoClientSettings) ReflectionTestUtils.getField(client, "settings");
+		return ((MongoClientImpl) client).getSettings();
 	}
 
 }
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/ServerPropertiesTests.java b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/ServerPropertiesTests.java
index 6234688ebc..02c0ab6e69 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/ServerPropertiesTests.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/ServerPropertiesTests.java
@@ -42,7 +42,7 @@ import org.apache.tomcat.util.net.AbstractEndpoint;
 import org.eclipse.jetty.server.HttpChannel;
 import org.eclipse.jetty.server.Request;
 import org.eclipse.jetty.server.Server;
-import org.eclipse.jetty.util.thread.ThreadPool;
+import org.eclipse.jetty.util.thread.QueuedThreadPool;
 import org.junit.jupiter.api.Test;
 import reactor.netty.http.HttpDecoderSpec;
 import reactor.netty.http.server.HttpRequestDecoderSpec;
@@ -430,11 +430,11 @@ class ServerPropertiesTests {
 	void jettyThreadPoolPropertyDefaultsShouldMatchServerDefault() {
 		JettyServletWebServerFactory jettyFactory = new JettyServletWebServerFactory(0);
 		JettyWebServer jetty = (JettyWebServer) jettyFactory.getWebServer();
-		Server server = (Server) ReflectionTestUtils.getField(jetty, "server");
-		ThreadPool threadPool = (ThreadPool) ReflectionTestUtils.getField(server, "_threadPool");
-		int idleTimeout = (int) ReflectionTestUtils.getField(threadPool, "_idleTimeout");
-		int maxThreads = (int) ReflectionTestUtils.getField(threadPool, "_maxThreads");
-		int minThreads = (int) ReflectionTestUtils.getField(threadPool, "_minThreads");
+		Server server = jetty.getServer();
+		QueuedThreadPool threadPool = (QueuedThreadPool) server.getThreadPool();
+		int idleTimeout = threadPool.getIdleTimeout();
+		int maxThreads = threadPool.getMaxThreads();
+		int minThreads = threadPool.getMinThreads();
 		assertThat(this.properties.getJetty().getThreads().getIdleTimeout().toMillis()).isEqualTo(idleTimeout);
 		assertThat(this.properties.getJetty().getThreads().getMax()).isEqualTo(maxThreads);
 		assertThat(this.properties.getJetty().getThreads().getMin()).isEqualTo(minThreads);
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfigurationTests.java b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfigurationTests.java
index 0f772bdd0f..a07ac94770 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfigurationTests.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/web/servlet/WebMvcAutoConfigurationTests.java
@@ -696,8 +696,8 @@ class WebMvcAutoConfigurationTests {
 		this.contextRunner.withPropertyValues(prefix + "static-locations:classpath:/welcome-page/")
 				.withUserConfiguration(CorsConfigurer.class).run((context) -> {
 					WelcomePageHandlerMapping bean = context.getBean(WelcomePageHandlerMapping.class);
-					UrlBasedCorsConfigurationSource source = (UrlBasedCorsConfigurationSource) ReflectionTestUtils
-							.getField(bean, "corsConfigurationSource");
+					UrlBasedCorsConfigurationSource source = (UrlBasedCorsConfigurationSource) bean
+							.getCorsConfigurationSource();
 					assertThat(source.getCorsConfigurations()).containsKey("/**");
 				});
 	}
diff --git a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/websocket/servlet/WebSocketMessagingAutoConfigurationTests.java b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/websocket/servlet/WebSocketMessagingAutoConfigurationTests.java
index b66b492d1c..7043d05f39 100644
--- a/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/websocket/servlet/WebSocketMessagingAutoConfigurationTests.java
+++ b/spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/websocket/servlet/WebSocketMessagingAutoConfigurationTests.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2020 the original author or authors.
+ * Copyright 2012-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -55,7 +55,6 @@ import org.springframework.messaging.simp.stomp.StompSession;
 import org.springframework.messaging.simp.stomp.StompSessionHandler;
 import org.springframework.messaging.simp.stomp.StompSessionHandlerAdapter;
 import org.springframework.stereotype.Controller;
-import org.springframework.test.util.ReflectionTestUtils;
 import org.springframework.web.client.RestTemplate;
 import org.springframework.web.socket.client.standard.StandardWebSocketClient;
 import org.springframework.web.socket.config.annotation.DelegatingWebSocketMessageBrokerConfiguration;
@@ -138,13 +137,10 @@ class WebSocketMessagingAutoConfigurationTests {
 		return customizedConverters;
 	}
 
-	@SuppressWarnings("unchecked")
 	private List<MessageConverter> getDefaultConverters() {
 		DelegatingWebSocketMessageBrokerConfiguration configuration = new DelegatingWebSocketMessageBrokerConfiguration();
-		// We shouldn't usually call this method directly since it's on a non-proxy config
-		CompositeMessageConverter compositeDefaultConverter = ReflectionTestUtils.invokeMethod(configuration,
-				"brokerMessageConverter");
-		return (List<MessageConverter>) ReflectionTestUtils.getField(compositeDefaultConverter, "converters");
+		CompositeMessageConverter compositeDefaultConverter = configuration.brokerMessageConverter();
+		return compositeDefaultConverter.getConverters();
 	}
 
 	private Object performStompSubscription(String topic) throws Throwable {