Apply 'instanceof pattern matching' in spring-web

Closes gh-29530

Author: divcon

spring-web/src/main/java/org/springframework/http/client/HttpComponentsClientHttpRequestFactory.java

@@ -202,8 +202,8 @@ public ClientHttpRequest createRequest(URI uri, HttpMethod httpMethod) throws IO
 		if (context.getAttribute(HttpClientContext.REQUEST_CONFIG) == null) {
 			// Use request configuration given by the user, when available
 			RequestConfig config = null;
-			if (httpRequest instanceof Configurable) {
-				config = ((Configurable) httpRequest).getConfig();
+			if (httpRequest instanceof Configurable configurable) {
+				config = configurable.getConfig();
 			}
 			if (config == null) {
 				config = createRequestConfig(client);
@@ -328,8 +328,8 @@ protected HttpContext createHttpContext(HttpMethod httpMethod, URI uri) {
 	@Override
 	public void destroy() throws Exception {
 		HttpClient httpClient = getHttpClient();
-		if (httpClient instanceof Closeable) {
-			((Closeable) httpClient).close();
+		if (httpClient instanceof Closeable closeable) {
+			closeable.close();
 		}
 	}
 

spring-web/src/main/java/org/springframework/http/client/reactive/HttpComponentsClientHttpConnector.java

@@ -159,9 +159,8 @@ public void completed(Message<HttpResponse, Publisher<ByteBuffer>> result) {
 		@Override
 		public void failed(Exception ex) {
 			Throwable t = ex;
-			if (t instanceof HttpStreamResetException) {
-				HttpStreamResetException httpStreamResetException = (HttpStreamResetException) ex;
-				t = httpStreamResetException.getCause();
+			if (t instanceof HttpStreamResetException hsre) {
+				t = hsre.getCause();
 			}
 			this.sink.error(t);
 		}

spring-web/src/main/java/org/springframework/http/client/reactive/JettyResourceFactory.java

@@ -131,25 +131,25 @@ public void afterPropertiesSet() throws Exception {
 		}
 		if (this.byteBufferPool == null) {
 			this.byteBufferPool = new MappedByteBufferPool(2048,
-					this.executor instanceof ThreadPool.SizedThreadPool
-							? ((ThreadPool.SizedThreadPool) this.executor).getMaxThreads() / 2
+					this.executor instanceof ThreadPool.SizedThreadPool sizedThreadPool
+							? sizedThreadPool.getMaxThreads() / 2
 							: ProcessorUtils.availableProcessors() * 2);
 		}
 		if (this.scheduler == null) {
 			this.scheduler = new ScheduledExecutorScheduler(name + "-scheduler", false);
 		}
 
-		if (this.executor instanceof LifeCycle) {
-			((LifeCycle)this.executor).start();
+		if (this.executor instanceof LifeCycle lifeCycle) {
+			lifeCycle.start();
 		}
 		this.scheduler.start();
 	}
 
 	@Override
 	public void destroy() throws Exception {
 		try {
-			if (this.executor instanceof LifeCycle) {
-				((LifeCycle)this.executor).stop();
+			if (this.executor instanceof LifeCycle lifeCycle) {
+				lifeCycle.stop();
 			}
 		}
 		catch (Throwable ex) {

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

@@ -67,10 +67,10 @@ public DecoderHttpMessageReader(Decoder<T> decoder) {
 	}
 
 	private static void initLogger(Decoder<?> decoder) {
-		if (decoder instanceof AbstractDecoder &&
+		if (decoder instanceof AbstractDecoder<?> abstractDecoder &&
 				decoder.getClass().getName().startsWith("org.springframework.core.codec")) {
-			Log logger = HttpLogging.forLog(((AbstractDecoder<?>) decoder).getLogger());
-			((AbstractDecoder<?>) decoder).setLogger(logger);
+			Log logger = HttpLogging.forLog(abstractDecoder.getLogger());
+			abstractDecoder.setLogger(logger);
 		}
 	}
 
@@ -163,9 +163,8 @@ public Mono<T> readMono(ResolvableType actualType, ResolvableType elementType,
 	protected Map<String, Object> getReadHints(ResolvableType actualType,
 			ResolvableType elementType, ServerHttpRequest request, ServerHttpResponse response) {
 
-		if (this.decoder instanceof HttpMessageDecoder) {
-			HttpMessageDecoder<?> decoder = (HttpMessageDecoder<?>) this.decoder;
-			return decoder.getDecodeHints(actualType, elementType, request, response);
+		if (this.decoder instanceof HttpMessageDecoder<?> httpMethodDecoder) {
+			return httpMethodDecoder.getDecodeHints(actualType, elementType, request, response);
 		}
 		return Hints.none();
 	}

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

@@ -79,10 +79,10 @@ public EncoderHttpMessageWriter(Encoder<T> encoder) {
 	}
 
 	private static void initLogger(Encoder<?> encoder) {
-		if (encoder instanceof AbstractEncoder &&
+		if (encoder instanceof AbstractEncoder<?> abstractEncoder &&
 				encoder.getClass().getName().startsWith("org.springframework.core.codec")) {
-			Log logger = HttpLogging.forLog(((AbstractEncoder<?>) encoder).getLogger());
-			((AbstractEncoder<?>) encoder).setLogger(logger);
+			Log logger = HttpLogging.forLog(abstractEncoder.getLogger());
+			abstractEncoder.setLogger(logger);
 		}
 	}
 
@@ -224,9 +224,8 @@ public Mono<Void> write(Publisher<? extends T> inputStream, ResolvableType actua
 	protected Map<String, Object> getWriteHints(ResolvableType streamType, ResolvableType elementType,
 			@Nullable MediaType mediaType, ServerHttpRequest request, ServerHttpResponse response) {
 
-		if (this.encoder instanceof HttpMessageEncoder) {
-			HttpMessageEncoder<?> encoder = (HttpMessageEncoder<?>) this.encoder;
-			return encoder.getEncodeHints(streamType, elementType, mediaType, request, response);
+		if (this.encoder instanceof HttpMessageEncoder<?> httpMessageEncoder) {
+			return httpMessageEncoder.getEncodeHints(streamType, elementType, mediaType, request, response);
 		}
 		return Hints.none();
 	}

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

@@ -179,7 +179,7 @@ private static long lengthOf(Resource resource) {
 	private static Optional<Mono<Void>> zeroCopy(Resource resource, @Nullable ResourceRegion region,
 			ReactiveHttpOutputMessage message, Map<String, Object> hints) {
 
-		if (message instanceof ZeroCopyHttpOutputMessage && resource.isFile()) {
+		if (message instanceof ZeroCopyHttpOutputMessage zeroCopyHttpOutputMessage && resource.isFile()) {
 			try {
 				File file = resource.getFile();
 				long pos = region != null ? region.getPosition() : 0;
@@ -188,7 +188,7 @@ private static Optional<Mono<Void>> zeroCopy(Resource resource, @Nullable Resour
 					String formatted = region != null ? "region " + pos + "-" + (count) + " of " : "";
 					logger.debug(Hints.getLogPrefix(hints) + "Zero-copy " + formatted + "[" + resource + "]");
 				}
-				return Optional.of(((ZeroCopyHttpOutputMessage) message).writeWith(file, pos, count));
+				return Optional.of(zeroCopyHttpOutputMessage.writeWith(file, pos, count));
 			}
 			catch (IOException ex) {
 				// should not happen

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

@@ -121,8 +121,8 @@ private Flux<Publisher<DataBuffer>> encode(Publisher<?> input, ResolvableType el
 
 		return Flux.from(input).map(element -> {
 
-			ServerSentEvent<?> sse = (element instanceof ServerSentEvent ?
-					(ServerSentEvent<?>) element : ServerSentEvent.builder().data(element).build());
+			ServerSentEvent<?> sse = (element instanceof ServerSentEvent<?> serverSentEvent ?
+					serverSentEvent : ServerSentEvent.builder().data(element).build());
 
 			StringBuilder sb = new StringBuilder();
 			String id = sse.id();
@@ -150,9 +150,9 @@ private Flux<Publisher<DataBuffer>> encode(Publisher<?> input, ResolvableType el
 			if (data == null) {
 				result = Flux.just(encodeText(sb + "\n", mediaType, factory));
 			}
-			else if (data instanceof String) {
-				data = StringUtils.replace((String) data, "\n", "\ndata:");
-				result = Flux.just(encodeText(sb + (String) data + "\n\n", mediaType, factory));
+			else if (data instanceof String dataString) {
+				dataString = StringUtils.replace(dataString, "\n", "\ndata:");
+				result = Flux.just(encodeText(sb + dataString + "\n\n", mediaType, factory));
 			}
 			else {
 				result = encodeEvent(sb, data, dataType, mediaType, factory, hints);
@@ -203,9 +203,8 @@ public Mono<Void> write(Publisher<?> input, ResolvableType actualType, Resolvabl
 	private Map<String, Object> getEncodeHints(ResolvableType actualType, ResolvableType elementType,
 			@Nullable MediaType mediaType, ServerHttpRequest request, ServerHttpResponse response) {
 
-		if (this.encoder instanceof HttpMessageEncoder) {
-			HttpMessageEncoder<?> encoder = (HttpMessageEncoder<?>) this.encoder;
-			return encoder.getEncodeHints(actualType, elementType, mediaType, request, response);
+		if (this.encoder instanceof HttpMessageEncoder<?> httpMessageEncoder) {
+			return httpMessageEncoder.getEncodeHints(actualType, elementType, mediaType, request, response);
 		}
 		return Hints.none();
 	}

spring-web/src/main/java/org/springframework/http/codec/json/AbstractJackson2Decoder.java

@@ -264,12 +264,12 @@ private void logValue(@Nullable Object value, @Nullable Map<String, Object> hint
 	}
 
 	private CodecException processException(IOException ex) {
-		if (ex instanceof InvalidDefinitionException) {
-			JavaType type = ((InvalidDefinitionException) ex).getType();
+		if (ex instanceof InvalidDefinitionException ide) {
+			JavaType type = ide.getType();
 			return new CodecException("Type definition error: " + type, ex);
 		}
-		if (ex instanceof JsonProcessingException) {
-			String originalMessage = ((JsonProcessingException) ex).getOriginalMessage();
+		if (ex instanceof JsonProcessingException jpe) {
+			String originalMessage = jpe.getOriginalMessage();
 			return new DecodingException("JSON decoding error: " + originalMessage, ex);
 		}
 		return new DecodingException("I/O error while parsing input stream", ex);

spring-web/src/main/java/org/springframework/http/codec/json/Jackson2CodecSupport.java

@@ -255,7 +255,7 @@ protected Map<String, Object> getHints(ResolvableType resolvableType) {
 
 	@Nullable
 	protected MethodParameter getParameter(ResolvableType type) {
-		return (type.getSource() instanceof MethodParameter ? (MethodParameter) type.getSource() : null);
+		return (type.getSource() instanceof MethodParameter methodParameter ? methodParameter : null);
 	}
 
 	@Nullable

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

@@ -129,7 +129,7 @@ private LinkedMultiValueMap<String, Part> toMultiValueMap(Map<String, Collection
 	}
 
 	private List<Part> toList(Collection<Part> collection) {
-		return collection instanceof List ? (List<Part>) collection : new ArrayList<>(collection);
+		return collection instanceof List<Part> partList ? partList : new ArrayList<>(collection);
 	}
 
 }