diff --git a/spring-test/src/test/java/org/springframework/test/web/servlet/samples/standalone/AsyncTests.java b/spring-test/src/test/java/org/springframework/test/web/servlet/samples/standalone/AsyncTests.java
index 103bcc96755..2c1c3202f99 100644
--- a/spring-test/src/test/java/org/springframework/test/web/servlet/samples/standalone/AsyncTests.java
+++ b/spring-test/src/test/java/org/springframework/test/web/servlet/samples/standalone/AsyncTests.java
@@ -17,6 +17,7 @@
 package org.springframework.test.web.servlet.samples.standalone;
 
 import java.io.StringWriter;
+import java.nio.charset.Charset;
 import java.nio.charset.StandardCharsets;
 import java.util.Collection;
 import java.util.concurrent.Callable;
@@ -40,6 +41,7 @@ import org.springframework.web.bind.annotation.RestController;
 import org.springframework.web.context.request.async.DeferredResult;
 import org.springframework.web.servlet.mvc.method.annotation.StreamingResponseBody;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.junit.Assert.*;
 import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.*;
 import static org.springframework.test.web.servlet.result.MockMvcResultHandlers.*;
@@ -78,7 +80,7 @@ public class AsyncTests {
 	public void streaming() throws Exception {
 		this.mockMvc.perform(get("/1").param("streaming", "true"))
 				.andExpect(request().asyncStarted())
-				.andDo(r -> r.getAsyncResult()) // fetch async result similar to "asyncDispatch" builder
+				.andDo(MvcResult::getAsyncResult) // fetch async result similar to "asyncDispatch" builder
 				.andExpect(status().isOk())
 				.andExpect(content().string("name=Joe"));
 	}
@@ -87,7 +89,7 @@ public class AsyncTests {
 	public void streamingSlow() throws Exception {
 		this.mockMvc.perform(get("/1").param("streamingSlow", "true"))
 				.andExpect(request().asyncStarted())
-				.andDo(r -> r.getAsyncResult())
+				.andDo(MvcResult::getAsyncResult)
 				.andExpect(status().isOk())
 				.andExpect(content().string("name=Joe&someBoolean=true"));
 	}
@@ -96,7 +98,7 @@ public class AsyncTests {
 	public void streamingJson() throws Exception {
 		this.mockMvc.perform(get("/1").param("streamingJson", "true"))
 				.andExpect(request().asyncStarted())
-				.andDo(r -> r.getAsyncResult())
+				.andDo(MvcResult::getAsyncResult)
 				.andExpect(status().isOk())
 				.andExpect(content().contentType(MediaType.APPLICATION_JSON_UTF8_VALUE))
 				.andExpect(content().string("{\"name\":\"Joe\",\"someDouble\":0.5}"));
@@ -129,10 +131,7 @@ public class AsyncTests {
 				.andExpect(content().string("{\"name\":\"Joe\",\"someDouble\":0.0,\"someBoolean\":false}"));
 	}
 
-	/**
-	 * SPR-13079
-	 */
-	@Test
+	@Test // SPR-13079
 	public void deferredResultWithDelayedError() throws Exception {
 		MvcResult mvcResult = this.mockMvc.perform(get("/1").param("deferredResultWithDelayedError", "true"))
 				.andExpect(request().asyncStarted())
@@ -201,6 +200,7 @@ public class AsyncTests {
 
 	@RestController
 	@RequestMapping(path = "/{id}", produces = "application/json")
+	@SuppressWarnings("unused")
 	private static class AsyncController {
 
 		private final Collection<DeferredResult<Person>> deferredResults =
@@ -217,7 +217,7 @@ public class AsyncTests {
 
 		@RequestMapping(params = "streaming")
 		public StreamingResponseBody getStreaming() {
-			return os -> os.write("name=Joe".getBytes());
+			return os -> os.write("name=Joe".getBytes(UTF_8));
 		}
 
 		@RequestMapping(params = "streamingSlow")
@@ -226,7 +226,7 @@ public class AsyncTests {
 				os.write("name=Joe".getBytes());
 				try {
 					Thread.sleep(200);
-					os.write("&someBoolean=true".getBytes());
+					os.write("&someBoolean=true".getBytes(UTF_8));
 				}
 				catch (InterruptedException e) {
 					/* no-op */
@@ -237,7 +237,7 @@ public class AsyncTests {
 		@RequestMapping(params = "streamingJson")
 		public ResponseEntity<StreamingResponseBody> getStreamingJson() {
 			return ResponseEntity.ok().contentType(MediaType.APPLICATION_JSON_UTF8)
-					.body(os -> os.write("{\"name\":\"Joe\",\"someDouble\":0.5}".getBytes(StandardCharsets.UTF_8)));
+					.body(os -> os.write("{\"name\":\"Joe\",\"someDouble\":0.5}".getBytes(UTF_8)));
 		}
 
 		@RequestMapping(params = "deferredResult")
@@ -291,7 +291,7 @@ public class AsyncTests {
 			return e.getMessage();
 		}
 
-		public void onMessage(String name) {
+		void onMessage(String name) {
 			for (DeferredResult<Person> deferredResult : this.deferredResults) {
 				deferredResult.setResult(new Person(name));
 				this.deferredResults.remove(deferredResult);