Nullability refinements and related polishing

spring-context/src/main/java/org/springframework/context/annotation/ConfigurationClass.java

@@ -211,9 +211,8 @@ final class ConfigurationClass {
 
 	public void validate(ProblemReporter problemReporter) {
 		// A configuration class may not be final (CGLIB limitation) unless it declares proxyBeanMethods=false
-		String annotationName = Configuration.class.getName();
-		if (this.metadata.isAnnotated(annotationName) &&
-				(Boolean) this.metadata.getAnnotationAttributes(annotationName).get("proxyBeanMethods")) {
+		Map<String, Object> attributes = this.metadata.getAnnotationAttributes(Configuration.class.getName());
+		if (attributes != null && (Boolean) attributes.get("proxyBeanMethods")) {
 			if (this.metadata.isFinal()) {
 				problemReporter.error(new FinalConfigurationProblem());
 			}

spring-messaging/src/main/java/org/springframework/messaging/handler/invocation/reactive/AbstractEncoderMethodReturnValueHandler.java

@@ -49,7 +49,7 @@ import org.springframework.util.MimeType;
  * Base class for a return value handler that encodes return values to
  * {@code Flux<DataBuffer>} through the configured {@link Encoder}s.
  *
- * <p>Sub-classes must implement the abstract method
+ * <p>Subclasses must implement the abstract method
  * {@link #handleEncodedContent} to handle the resulting encoded content.
  *
  * <p>This handler should be ordered last since its {@link #supportsReturnType}
@@ -69,7 +69,6 @@ public abstract class AbstractEncoderMethodReturnValueHandler implements Handler
 
 	protected final Log logger = LogFactory.getLog(getClass());
 
-
 	private final List<Encoder<?>> encoders;
 
 	private final ReactiveAdapterRegistry adapterRegistry;
@@ -118,7 +117,6 @@ public abstract class AbstractEncoderMethodReturnValueHandler implements Handler
 				.getOrDefault(HandlerMethodReturnValueHandler.DATA_BUFFER_FACTORY_HEADER, this.defaultBufferFactory);
 
 		MimeType mimeType = (MimeType) message.getHeaders().get(MessageHeaders.CONTENT_TYPE);
-
 		Flux<DataBuffer> encodedContent = encodeContent(
 				returnValue, returnType, bufferFactory, mimeType, Collections.emptyMap());
 
@@ -147,8 +145,8 @@ public abstract class AbstractEncoderMethodReturnValueHandler implements Handler
 		}
 		else {
 			publisher = Mono.justOrEmpty(content);
-			elementType = returnValueType.toClass() == Object.class && content != null ?
-					ResolvableType.forInstance(content) : returnValueType;
+			elementType = (returnValueType.toClass() == Object.class && content != null ?
+					ResolvableType.forInstance(content) : returnValueType);
 		}
 
 		if (elementType.resolve() == void.class || elementType.resolve() == Void.class) {
@@ -156,7 +154,6 @@ public abstract class AbstractEncoderMethodReturnValueHandler implements Handler
 		}
 
 		Encoder<?> encoder = getEncoder(elementType, mimeType);
-
 		return Flux.from((Publisher) publisher).map(value ->
 				encodeValue(value, elementType, encoder, bufferFactory, mimeType, hints));
 	}
@@ -201,9 +198,8 @@ public abstract class AbstractEncoderMethodReturnValueHandler implements Handler
 	}
 
 	/**
-	 * Sub-classes implement this method to handle encoded values in some way
+	 * Subclasses implement this method to handle encoded values in some way
 	 * such as creating and sending messages.
-	 *
 	 * @param encodedContent the encoded content; each {@code DataBuffer}
 	 * represents the fully-aggregated, encoded content for one value
 	 * (i.e. payload) returned from the HandlerMethod.
@@ -229,9 +225,12 @@ public abstract class AbstractEncoderMethodReturnValueHandler implements Handler
 	 */
 	private static class KotlinDelegate {
 
-		static private boolean isSuspend(Method method) {
+		static private boolean isSuspend(@Nullable Method method) {
+			if (method == null) {
+				return false;
+			}
 			KFunction<?> function = ReflectJvmMapping.getKotlinFunction(method);
-			return function != null && function.isSuspend();
+			return (function != null && function.isSuspend());
 		}
 	}
 

spring-web/src/main/java/org/springframework/http/codec/multipart/DefaultMultipartMessageReader.java

@@ -44,6 +44,7 @@ import org.springframework.http.ReactiveHttpInputMessage;
 import org.springframework.http.codec.HttpMessageReader;
 import org.springframework.http.codec.LoggingCodecSupport;
 import org.springframework.lang.Nullable;
+import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
 /**
@@ -57,8 +58,7 @@ import org.springframework.util.StringUtils;
  * @since 5.2
  * @see MultipartHttpMessageReader
  */
-public class DefaultMultipartMessageReader extends LoggingCodecSupport
-		implements HttpMessageReader<Part> {
+public class DefaultMultipartMessageReader extends LoggingCodecSupport implements HttpMessageReader<Part> {
 
 	private static final byte CR = '\r';
 
@@ -74,8 +74,7 @@ public class DefaultMultipartMessageReader extends LoggingCodecSupport
 
 	private static final String HEADER_SEPARATOR = "\\r\\n";
 
-	private static final DataBufferUtils.Matcher HEADER_MATCHER =
-			DataBufferUtils.matcher(HEADER_BODY_SEPARATOR);
+	private static final DataBufferUtils.Matcher HEADER_MATCHER = DataBufferUtils.matcher(HEADER_BODY_SEPARATOR);
 
 
 	@Override
@@ -85,14 +84,12 @@ public class DefaultMultipartMessageReader extends LoggingCodecSupport
 
 	@Override
 	public boolean canRead(ResolvableType elementType, @Nullable MediaType mediaType) {
-		return Part.class.equals(elementType.toClass()) &&
-				(mediaType == null || MediaType.MULTIPART_FORM_DATA.isCompatibleWith(mediaType));
+		return (Part.class.equals(elementType.toClass()) &&
+				(mediaType == null || MediaType.MULTIPART_FORM_DATA.isCompatibleWith(mediaType)));
 	}
 
 	@Override
-	public Flux<Part> read(ResolvableType elementType, ReactiveHttpInputMessage message,
-			Map<String, Object> hints) {
-
+	public Flux<Part> read(ResolvableType elementType, ReactiveHttpInputMessage message, Map<String, Object> hints) {
 		byte[] boundary = boundary(message);
 		if (boundary == null) {
 			return Flux.error(new CodecException("No multipart boundary found in Content-Type: \"" +
@@ -126,12 +123,9 @@ public class DefaultMultipartMessageReader extends LoggingCodecSupport
 	 * all data until then. Note that the first boundary of a multipart message does not contain
 	 * the initial \r\n, hence the need for a special boundary matcher.
 	 */
-	private static Flux<DataBuffer> skipUntilFirstBoundary(Flux<DataBuffer> dataBuffers,
-			byte[] boundary) {
-
+	private static Flux<DataBuffer> skipUntilFirstBoundary(Flux<DataBuffer> dataBuffers, byte[] boundary) {
 		byte[] needle = concat(FIRST_BOUNDARY_PREFIX, boundary);
 		DataBufferUtils.Matcher matcher = DataBufferUtils.matcher(needle);
-
 		AtomicBoolean found = new AtomicBoolean();
 
 		return dataBuffers.concatMap(dataBuffer -> {
@@ -152,7 +146,6 @@ public class DefaultMultipartMessageReader extends LoggingCodecSupport
 					return Mono.empty();
 				}
 			}
-
 		});
 	}
 
@@ -163,8 +156,7 @@ public class DefaultMultipartMessageReader extends LoggingCodecSupport
 	private static boolean notLastBoundary(DataBuffer dataBuffer) {
 		if (dataBuffer.readableByteCount() >= 2) {
 			int readPosition = dataBuffer.readPosition();
-			if ((dataBuffer.getByte(readPosition) == HYPHEN) &&
-					(dataBuffer.getByte(readPosition + 1) == HYPHEN)) {
+			if (dataBuffer.getByte(readPosition) == HYPHEN && dataBuffer.getByte(readPosition + 1) == HYPHEN) {
 				DataBufferUtils.release(dataBuffer);
 				return false;
 			}
@@ -180,8 +172,7 @@ public class DefaultMultipartMessageReader extends LoggingCodecSupport
 	private static Part toPart(DataBuffer dataBuffer) {
 		int readPosition = dataBuffer.readPosition();
 		if (dataBuffer.readableByteCount() >= 2) {
-			if ( (dataBuffer.getByte(readPosition) == CR) &&
-				(dataBuffer.getByte(readPosition + 1) == LF)) {
+			if (dataBuffer.getByte(readPosition) == CR && dataBuffer.getByte(readPosition + 1) == LF) {
 				dataBuffer.readPosition(readPosition + 2);
 			}
 		}
@@ -191,8 +182,7 @@ public class DefaultMultipartMessageReader extends LoggingCodecSupport
 		DataBuffer body;
 		if (endIdx > 0) {
 			readPosition = dataBuffer.readPosition();
-			int headersLength =
-					endIdx + 1 - (readPosition + HEADER_BODY_SEPARATOR.length);
+			int headersLength = endIdx + 1 - (readPosition + HEADER_BODY_SEPARATOR.length);
 			DataBuffer headersBuffer = dataBuffer.retainedSlice(readPosition, headersLength);
 			int bodyLength = dataBuffer.writePosition() - (1 + endIdx);
 			body = dataBuffer.retainedSlice(endIdx + 1, bodyLength);
@@ -275,7 +265,6 @@ public class DefaultMultipartMessageReader extends LoggingCodecSupport
 
 		protected final DataBuffer body;
 
-
 		public DefaultPart(HttpHeaders headers, DataBuffer body) {
 			this.headers = headers;
 			this.body = body;
@@ -283,7 +272,9 @@ public class DefaultMultipartMessageReader extends LoggingCodecSupport
 
 		@Override
 		public String name() {
-			return headers().getContentDisposition().getName();
+			String name = headers().getContentDisposition().getName();
+			Assert.state(name != null, "No name available");
+			return name;
 		}
 
 		@Override
@@ -295,7 +286,6 @@ public class DefaultMultipartMessageReader extends LoggingCodecSupport
 		public Flux<DataBuffer> content() {
 			return Flux.just(this.body);
 		}
-
 	}
 
 
@@ -342,14 +332,15 @@ public class DefaultMultipartMessageReader extends LoggingCodecSupport
 
 		@Override
 		public String filename() {
-			return headers().getContentDisposition().getFilename();
+			String filename = headers().getContentDisposition().getFilename();
+			Assert.state(filename != null, "No filename available");
+			return filename;
 		}
 
 		@Override
 		public Mono<Void> transferTo(Path dest) {
 			return Mono.using(() -> AsynchronousFileChannel.open(dest, StandardOpenOption.WRITE),
-					this::writeBody,
-					this::close);
+					this::writeBody, this::close);
 		}
 
 		private Mono<Void> writeBody(AsynchronousFileChannel channel) {
@@ -366,4 +357,5 @@ public class DefaultMultipartMessageReader extends LoggingCodecSupport
 			}
 		}
 	}
+
 }