Polish: remove unused private fields, remove empty operator

spring-core/src/main/java/org/springframework/core/io/buffer/DataBufferUtils.java

@@ -31,7 +31,6 @@ import java.nio.file.StandardOpenOption;
 import java.util.concurrent.Callable;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicLong;
-import java.util.function.BinaryOperator;
 import java.util.function.Consumer;
 
 import org.reactivestreams.Publisher;
@@ -57,13 +56,6 @@ public abstract class DataBufferUtils {
 
 	private static final Consumer<DataBuffer> RELEASE_CONSUMER = DataBufferUtils::release;
 
-	private static final BinaryOperator<DataBuffer> WRITE_AGGREGATOR =
-			(dataBuffer1, dataBuffer2) -> {
-				DataBuffer result = dataBuffer1.write(dataBuffer2);
-				release(dataBuffer2);
-				return result;
-			};
-
 	//---------------------------------------------------------------------
 	// Reading
 	//---------------------------------------------------------------------

spring-expression/src/main/java/org/springframework/expression/spel/ast/MethodReference.java

@@ -321,7 +321,7 @@ public class MethodReference extends SpelNodeImpl {
 			Class<?> publicDeclaringClass = methodExecutor.getPublicDeclaringClass();
 			Assert.state(publicDeclaringClass != null, "No public declaring class");
 			classDesc = publicDeclaringClass.getName().replace('.', '/');
-		};
+		}
 
 		if (!isStaticMethod) {
 			if (descriptor == null || !descriptor.substring(1).equals(classDesc)) {

spring-test/src/main/java/org/springframework/test/web/servlet/result/ModelResultMatchers.java

@@ -239,7 +239,7 @@ public class ModelResultMatchers {
 		ModelAndView mav = mvcResult.getModelAndView();
 		if (mav == null) {
 			fail("No ModelAndView found");
-		};
+		}
 		return mav;
 	}
 

spring-web/src/main/java/org/springframework/http/server/DefaultPathContainer.java

@@ -194,8 +194,6 @@ class DefaultPathContainer implements PathContainer {
 
 		private final String value;
 
-		private final char[] valueAsChars;
-
 		private final String valueToMatch;
 
 		private final char[] valueToMatchAsChars;
@@ -206,7 +204,6 @@ class DefaultPathContainer implements PathContainer {
 		DefaultPathSegment(String value, String valueToMatch, MultiValueMap<String, String> params) {
 			Assert.isTrue(!value.contains("/"), () -> "Invalid path segment value: " + value);
 			this.value = value;
-			this.valueAsChars = value.toCharArray();
 			this.valueToMatch = valueToMatch;
 			this.valueToMatchAsChars = valueToMatch.toCharArray();
 			this.parameters = CollectionUtils.unmodifiableMultiValueMap(params);

spring-web/src/main/java/org/springframework/http/server/reactive/ServletHttpHandlerAdapter.java

@@ -254,7 +254,7 @@ public class ServletHttpHandlerAdapter implements Servlet {
 		public void onComplete(AsyncEvent event) {
 			// no-op
 		}
-	};
+	}
 
 
 	private class HandlerResultSubscriber implements Subscriber<Void> {

spring-web/src/main/java/org/springframework/web/util/DefaultUriBuilderFactory.java

@@ -40,7 +40,7 @@ import org.springframework.util.ObjectUtils;
  */
 public class DefaultUriBuilderFactory implements UriBuilderFactory {
 
-	public enum EncodingMode {URI_COMPONENT, VALUES_ONLY, NONE };
+	public enum EncodingMode {URI_COMPONENT, VALUES_ONLY, NONE }
 
 
 	private final UriComponentsBuilder baseUri;

spring-webflux/src/main/java/org/springframework/web/reactive/result/SimpleHandlerAdapter.java

@@ -16,11 +16,9 @@
 
 package org.springframework.web.reactive.result;
 
-import java.lang.reflect.Method;
 
 import reactor.core.publisher.Mono;
 
-import org.springframework.core.MethodParameter;
 import org.springframework.web.reactive.DispatcherHandler;
 import org.springframework.web.reactive.HandlerAdapter;
 import org.springframework.web.reactive.HandlerResult;
@@ -37,20 +35,6 @@ import org.springframework.web.server.WebHandler;
  */
 public class SimpleHandlerAdapter implements HandlerAdapter {
 
-	private static final MethodParameter RETURN_TYPE;
-
-	static {
-		try {
-			Method method = WebHandler.class.getMethod("handle", ServerWebExchange.class);
-			RETURN_TYPE = new MethodParameter(method, -1);
-		}
-		catch (NoSuchMethodException ex) {
-			throw new IllegalStateException(
-					"Failed to initialize the return type for WebHandler: " + ex.getMessage());
-		}
-	}
-
-
 	@Override
 	public boolean supports(Object handler) {
 		return WebHandler.class.isAssignableFrom(handler.getClass());

spring-websocket/src/main/java/org/springframework/web/socket/config/annotation/WebMvcStompEndpointRegistry.java

@@ -90,7 +90,7 @@ public class WebMvcStompEndpointRegistry implements StompEndpointRegistry {
 		WebSocketHandler actual = WebSocketHandlerDecorator.unwrap(handler);
 		if (!(actual instanceof SubProtocolWebSocketHandler)) {
 			throw new IllegalArgumentException("No SubProtocolWebSocketHandler in " + handler);
-		};
+		}
 		return (SubProtocolWebSocketHandler) actual;
 	}