diff --git a/spring-core/src/main/java/org/springframework/core/codec/StringDecoder.java b/spring-core/src/main/java/org/springframework/core/codec/StringDecoder.java
index 8aca34f420c..1fa83358038 100644
--- a/spring-core/src/main/java/org/springframework/core/codec/StringDecoder.java
+++ b/spring-core/src/main/java/org/springframework/core/codec/StringDecoder.java
@@ -110,8 +110,8 @@ public final class StringDecoder extends AbstractDataBufferDecoder<String> {
 	}
 
 	/**
-	 * Splits the given data buffer on delimiter boundaries. The returned Flux contains a
-	 * {@link #END_FRAME} buffer after each delimiter.
+	 * Split the given data buffer on delimiter boundaries.
+	 * The returned Flux contains an {@link #END_FRAME} buffer after each delimiter.
 	 */
 	private List<DataBuffer> splitOnDelimiter(DataBuffer dataBuffer, List<byte[]> delimiterBytes) {
 		List<DataBuffer> frames = new ArrayList<>();
@@ -180,15 +180,14 @@ public final class StringDecoder extends AbstractDataBufferDecoder<String> {
 	}
 
 	/**
-	 * Checks whether the given buffer is {@link #END_FRAME}.
+	 * Check whether the given buffer is {@link #END_FRAME}.
 	 */
 	private static boolean isEndFrame(DataBuffer dataBuffer) {
 		return dataBuffer == END_FRAME;
 	}
 
 	/**
-	 * Joins the given list of buffers into a single buffer, also removing
-	 * the (inserted) {@link #END_FRAME}.
+	 * Join the given list of buffers into a single buffer.
 	 */
 	private static DataBuffer joinUntilEndFrame(List<DataBuffer> dataBuffers) {
 		if (!dataBuffers.isEmpty()) {
@@ -229,7 +228,7 @@ public final class StringDecoder extends AbstractDataBufferDecoder<String> {
 	 * Create a {@code StringDecoder} for {@code "text/plain"}.
 	 * @param ignored ignored
 	 * @deprecated as of Spring 5.0.4, in favor of {@link #textPlainOnly()} or
-	 * {@link #textPlainOnly(List, boolean)}.
+	 * {@link #textPlainOnly(List, boolean)}
 	 */
 	@Deprecated
 	public static StringDecoder textPlainOnly(boolean ignored) {
@@ -247,7 +246,7 @@ public final class StringDecoder extends AbstractDataBufferDecoder<String> {
 	 * Create a {@code StringDecoder} for {@code "text/plain"}.
 	 * @param delimiters delimiter strings to use to split the input stream
 	 * @param stripDelimiter whether to remove delimiters from the resulting
-	 * input strings.
+	 * input strings
 	 */
 	public static StringDecoder textPlainOnly(List<String> delimiters, boolean stripDelimiter) {
 		return new StringDecoder(delimiters, stripDelimiter, new MimeType("text", "plain", DEFAULT_CHARSET));
@@ -257,7 +256,7 @@ public final class StringDecoder extends AbstractDataBufferDecoder<String> {
 	 * Create a {@code StringDecoder} that supports all MIME types.
 	 * @param ignored ignored
 	 * @deprecated as of Spring 5.0.4, in favor of {@link #allMimeTypes()} or
-	 * {@link #allMimeTypes(List, boolean)}.
+	 * {@link #allMimeTypes(List, boolean)}
 	 */
 	@Deprecated
 	public static StringDecoder allMimeTypes(boolean ignored) {
@@ -275,7 +274,7 @@ public final class StringDecoder extends AbstractDataBufferDecoder<String> {
 	 * Create a {@code StringDecoder} that supports all MIME types.
 	 * @param delimiters delimiter strings to use to split the input stream
 	 * @param stripDelimiter whether to remove delimiters from the resulting
-	 * input strings.
+	 * input strings
 	 */
 	public static StringDecoder allMimeTypes(List<String> delimiters, boolean stripDelimiter) {
 		return new StringDecoder(delimiters, stripDelimiter,
diff --git a/spring-core/src/test/java/org/springframework/core/codec/StringDecoderTests.java b/spring-core/src/test/java/org/springframework/core/codec/StringDecoderTests.java
index 8768de85c38..9cc82d73a1c 100644
--- a/spring-core/src/test/java/org/springframework/core/codec/StringDecoderTests.java
+++ b/spring-core/src/test/java/org/springframework/core/codec/StringDecoderTests.java
@@ -34,12 +34,12 @@ import org.springframework.lang.Nullable;
 import org.springframework.util.MimeType;
 import org.springframework.util.MimeTypeUtils;
 
-import static java.nio.charset.StandardCharsets.UTF_16BE;
-import static java.nio.charset.StandardCharsets.UTF_8;
+import static java.nio.charset.StandardCharsets.*;
 import static org.junit.Assert.*;
 
 /**
  * Unit tests for {@link StringDecoder}.
+ *
  * @author Sebastien Deleuze
  * @author Brian Clozel
  * @author Mark Paluch
@@ -48,29 +48,21 @@ public class StringDecoderTests extends AbstractDecoderTestCase<StringDecoder> {
 
 	private static final ResolvableType TYPE = ResolvableType.forClass(String.class);
 
+
 	public StringDecoderTests() {
 		super(StringDecoder.allMimeTypes());
 	}
 
+
 	@Override
 	@Test
 	public void canDecode() {
-		assertTrue(this.decoder.canDecode(
-				TYPE, MimeTypeUtils.TEXT_PLAIN));
-
-		assertTrue(this.decoder.canDecode(
-				TYPE, MimeTypeUtils.TEXT_HTML));
-
-		assertTrue(this.decoder.canDecode(
-				TYPE, MimeTypeUtils.APPLICATION_JSON));
-
-		assertTrue(this.decoder.canDecode(
-				TYPE, MimeTypeUtils.parseMimeType("text/plain;charset=utf-8")));
-
-
+		assertTrue(this.decoder.canDecode(TYPE, MimeTypeUtils.TEXT_PLAIN));
+		assertTrue(this.decoder.canDecode(TYPE, MimeTypeUtils.TEXT_HTML));
+		assertTrue(this.decoder.canDecode(TYPE, MimeTypeUtils.APPLICATION_JSON));
+		assertTrue(this.decoder.canDecode(TYPE, MimeTypeUtils.parseMimeType("text/plain;charset=utf-8")));
 		assertFalse(this.decoder.canDecode(
 				ResolvableType.forClass(Integer.class), MimeTypeUtils.TEXT_PLAIN));
-
 		assertFalse(this.decoder.canDecode(
 				ResolvableType.forClass(Object.class), MimeTypeUtils.APPLICATION_JSON));
 	}
@@ -157,7 +149,6 @@ public class StringDecoderTests extends AbstractDecoderTestCase<StringDecoder> {
 
 	@Test
 	public void decodeNewLineIncludeDelimiters() {
-
 		this.decoder = StringDecoder.allMimeTypes(StringDecoder.DEFAULT_DELIMITERS, false);
 
 		Flux<DataBuffer> input = Flux.just(
@@ -219,7 +210,7 @@ public class StringDecoderTests extends AbstractDecoderTestCase<StringDecoder> {
 	}
 
 	@Test
-	public void decodeToMonoWithEmptyFlux() throws InterruptedException {
+	public void decodeToMonoWithEmptyFlux() {
 		Flux<DataBuffer> input = Flux.empty();
 
 		testDecodeToMono(input, String.class, step -> step
diff --git a/spring-web/src/main/java/org/springframework/http/codec/xml/Jaxb2XmlDecoder.java b/spring-web/src/main/java/org/springframework/http/codec/xml/Jaxb2XmlDecoder.java
index 1b5b15e747a..8f3c6e0d3b8 100644
--- a/spring-web/src/main/java/org/springframework/http/codec/xml/Jaxb2XmlDecoder.java
+++ b/spring-web/src/main/java/org/springframework/http/codec/xml/Jaxb2XmlDecoder.java
@@ -103,14 +103,9 @@ public class Jaxb2XmlDecoder extends AbstractDecoder<Object> {
 
 	@Override
 	public boolean canDecode(ResolvableType elementType, @Nullable MimeType mimeType) {
-		if (super.canDecode(elementType, mimeType)) {
-			Class<?> outputClass = elementType.toClass();
-			return (outputClass.isAnnotationPresent(XmlRootElement.class) ||
-					outputClass.isAnnotationPresent(XmlType.class));
-		}
-		else {
-			return false;
-		}
+		Class<?> outputClass = elementType.toClass();
+		return (outputClass.isAnnotationPresent(XmlRootElement.class) ||
+				outputClass.isAnnotationPresent(XmlType.class)) && super.canDecode(elementType, mimeType);
 	}
 
 	@Override