Avoid String allocations with Assert.isTrue()

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

@@ -177,7 +177,7 @@ public abstract class DataBufferUtils {
 		if (options.length > 0) {
 			for (OpenOption option : options) {
 				Assert.isTrue(!(option == StandardOpenOption.APPEND || option == StandardOpenOption.WRITE),
-						"'" + option + "' not allowed");
+						() -> "'" + option + "' not allowed");
 			}
 		}
 

spring-messaging/src/main/java/org/springframework/messaging/rsocket/DefaultRSocketRequesterBuilder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -103,7 +103,7 @@ final class DefaultRSocketRequesterBuilder implements RSocketRequester.Builder {
 
 	@Override
 	public RSocketRequester.Builder metadataMimeType(MimeType mimeType) {
-		Assert.notNull(mimeType, "`metadataMimeType` is required");
+		Assert.notNull(mimeType, "'metadataMimeType' is required");
 		this.metadataMimeType = mimeType;
 		return this;
 	}
@@ -281,7 +281,7 @@ final class DefaultRSocketRequesterBuilder implements RSocketRequester.Builder {
 		Mono<DataBuffer> dataMono = Mono.empty();
 		if (data != null) {
 			ReactiveAdapter adapter = strategies.reactiveAdapterRegistry().getAdapter(data.getClass());
-			Assert.isTrue(adapter == null || !adapter.isMultiValue(), "Expected single value: " + data);
+			Assert.isTrue(adapter == null || !adapter.isMultiValue(), () -> "Expected single value: " + data);
 			Mono<?> mono = (adapter != null ? Mono.from(adapter.toPublisher(data)) : Mono.just(data));
 			dataMono = mono.map(value -> {
 				ResolvableType type = ResolvableType.forClass(value.getClass());

spring-messaging/src/main/java/org/springframework/messaging/rsocket/MetadataEncoder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -141,7 +141,8 @@ final class MetadataEncoder {
 		}
 		ReactiveAdapter adapter = this.strategies.reactiveAdapterRegistry().getAdapter(metadata.getClass());
 		if (adapter != null) {
-			Assert.isTrue(!adapter.isMultiValue(), "Expected single value: " + metadata);
+			Object originalMetadata = metadata;
+			Assert.isTrue(!adapter.isMultiValue(), () -> "Expected single value: " + originalMetadata);
 			metadata = Mono.from(adapter.toPublisher(metadata)).defaultIfEmpty(NO_VALUE);
 			this.hasAsyncValues = true;
 		}

spring-messaging/src/main/java/org/springframework/messaging/rsocket/annotation/support/RSocketMessageHandler.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -421,7 +421,7 @@ public class RSocketMessageHandler extends MessageMappingMessageHandler {
 		String str = setupPayload.dataMimeType();
 		MimeType dataMimeType = StringUtils.hasText(str) ? MimeTypeUtils.parseMimeType(str) : this.defaultDataMimeType;
 		Assert.notNull(dataMimeType, "No `dataMimeType` in ConnectionSetupPayload and no default value");
-		Assert.isTrue(isDataMimeTypeSupported(dataMimeType), "Data MimeType '" + dataMimeType + "' not supported");
+		Assert.isTrue(isDataMimeTypeSupported(dataMimeType), () -> "Data MimeType '" + dataMimeType + "' not supported");
 
 		str = setupPayload.metadataMimeType();
 		MimeType metaMimeType = StringUtils.hasText(str) ? MimeTypeUtils.parseMimeType(str) : this.defaultMetadataMimeType;

spring-messaging/src/main/java/org/springframework/messaging/simp/SimpMessagingTemplate.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -138,7 +138,7 @@ public class SimpMessagingTemplate extends AbstractMessageSendingTemplate<String
 	 */
 	@Override
 	public void send(Message<?> message) {
-		Assert.notNull(message, "Message is required");
+		Assert.notNull(message, "Message must not be null");
 		String destination = SimpMessageHeaderAccessor.getDestination(message.getHeaders());
 		if (destination != null) {
 			sendInternal(message);
@@ -224,7 +224,8 @@ public class SimpMessagingTemplate extends AbstractMessageSendingTemplate<String
 			throws MessagingException {
 
 		Assert.notNull(user, "User must not be null");
-		Assert.isTrue(!user.contains("%2F"), "Invalid sequence \"%2F\" in user name: " + user);
+		String username = user;
+		Assert.isTrue(!user.contains("%2F"), () -> "Invalid sequence \"%2F\" in user name: " + username);
 		user = StringUtils.replace(user, "/", "%2F");
 		destination = destination.startsWith("/") ? destination : "/" + destination;
 		super.convertAndSend(this.destinationPrefix + user + destination, payload, headers, postProcessor);

spring-messaging/src/main/java/org/springframework/messaging/simp/broker/OrderedMessageChannelDecorator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -148,7 +148,7 @@ public class OrderedMessageChannelDecorator implements MessageChannel {
 	public static void configureInterceptor(MessageChannel channel, boolean preserveOrder) {
 		if (preserveOrder) {
 			Assert.isInstanceOf(ExecutorSubscribableChannel.class, channel,
-					"An ExecutorSubscribableChannel is required for `preservePublishOrder`");
+					"An ExecutorSubscribableChannel is required for 'preservePublishOrder'");
 			ExecutorSubscribableChannel execChannel = (ExecutorSubscribableChannel) channel;
 			if (execChannel.getInterceptors().stream().noneMatch(i -> i instanceof CallbackInterceptor)) {
 				execChannel.addInterceptor(0, new CallbackInterceptor());

spring-messaging/src/main/java/org/springframework/messaging/simp/stomp/StompHeaders.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -211,7 +211,7 @@ public class StompHeaders implements MultiValueMap<String, String>, Serializable
 		}
 		Arrays.stream(acceptVersions).forEach(version ->
 				Assert.isTrue(version != null && (version.equals("1.1") || version.equals("1.2")),
-						"Invalid version: " + version));
+						() -> "Invalid version: " + version));
 		set(ACCEPT_VERSION, StringUtils.arrayToCommaDelimitedString(acceptVersions));
 	}
 

spring-messaging/src/main/java/org/springframework/messaging/simp/user/DefaultUserDestinationResolver.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -203,7 +203,7 @@ public class DefaultUserDestinationResolver implements UserDestinationResolver {
 		}
 		Principal principal = SimpMessageHeaderAccessor.getUser(headers);
 		String user = (principal != null ? principal.getName() : null);
-		Assert.isTrue(user == null || !user.contains("%2F"), "Invalid sequence \"%2F\" in user name: " + user);
+		Assert.isTrue(user == null || !user.contains("%2F"), () -> "Invalid sequence \"%2F\" in user name: " + user);
 		Set<String> sessionIds = Collections.singleton(sessionId);
 		return new ParseResult(sourceDestination, actualDestination, sourceDestination, sessionIds, user);
 	}

spring-test/src/main/java/org/springframework/test/web/reactive/server/DefaultWebTestClientBuilder.java

@@ -230,7 +230,7 @@ class DefaultWebTestClientBuilder implements WebTestClient.Builder {
 
 	@Override
 	public WebTestClient.Builder entityExchangeResultConsumer(Consumer<EntityExchangeResult<?>> entityResultConsumer) {
-		Assert.notNull(entityResultConsumer, "`entityResultConsumer` is required");
+		Assert.notNull(entityResultConsumer, "'entityResultConsumer' is required");
 		this.entityResultConsumer = this.entityResultConsumer.andThen(entityResultConsumer);
 		return this;
 	}

spring-test/src/main/java/org/springframework/test/web/servlet/request/MockHttpServletRequestBuilder.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -148,8 +148,8 @@ public class MockHttpServletRequestBuilder
 
 	private static URI initUri(String url, Object[] vars) {
 		Assert.notNull(url, "'url' must not be null");
-		Assert.isTrue(url.startsWith("/") || url.startsWith("http://") || url.startsWith("https://"), "" +
+		Assert.isTrue(url.startsWith("/") || url.startsWith("http://") || url.startsWith("https://"),
-				"'url' should start with a path or be a complete HTTP URL: " + url);
+				() -> "'url' should start with a path or be a complete HTTP URL: " + url);
 		return UriComponentsBuilder.fromUriString(url).buildAndExpand(vars).encode().toUri();
 	}
 

spring-test/src/test/java/org/springframework/test/context/junit4/hybrid/HybridContextLoader.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -42,8 +42,8 @@ public class HybridContextLoader extends AbstractGenericContextLoader {
 
 	@Override
 	protected void validateMergedContextConfiguration(MergedContextConfiguration mergedConfig) {
-		Assert.isTrue(mergedConfig.hasClasses() || mergedConfig.hasLocations(), getClass().getSimpleName()
+		Assert.isTrue(mergedConfig.hasResources(),
-				+ " requires either classes or locations");
+				() -> getClass().getSimpleName() + " requires either classes or locations");
 	}
 
 	@Override

spring-web/src/main/java/org/springframework/http/ContentDisposition.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -465,7 +465,7 @@ public final class ContentDisposition {
 	 * @see <a href="https://tools.ietf.org/html/rfc5987">RFC 5987</a>
 	 */
 	private static String decodeFilename(String filename, Charset charset) {
-		Assert.notNull(filename, "'input' String` should not be null");
+		Assert.notNull(filename, "'input' String should not be null");
 		Assert.notNull(charset, "'charset' should not be null");
 		byte[] value = filename.getBytes(charset);
 		ByteArrayOutputStream baos = new ByteArrayOutputStream();
@@ -531,10 +531,10 @@ public final class ContentDisposition {
 	 * @see <a href="https://tools.ietf.org/html/rfc5987">RFC 5987</a>
 	 */
 	private static String encodeFilename(String input, Charset charset) {
-		Assert.notNull(input, "`input` is required");
+		Assert.notNull(input, "'input' is required");
-		Assert.notNull(charset, "`charset` is required");
+		Assert.notNull(charset, "'charset' is required");
 		Assert.isTrue(!StandardCharsets.US_ASCII.equals(charset), "ASCII does not require encoding");
-		Assert.isTrue(UTF_8.equals(charset) || ISO_8859_1.equals(charset), "Only UTF-8 and ISO-8859-1 supported.");
+		Assert.isTrue(UTF_8.equals(charset) || ISO_8859_1.equals(charset), "Only UTF-8 and ISO-8859-1 are supported");
 		byte[] source = input.getBytes(charset);
 		int len = source.length;
 		StringBuilder sb = new StringBuilder(len << 1);

spring-web/src/main/java/org/springframework/http/HttpRange.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -65,7 +65,7 @@ public abstract class HttpRange {
 		long contentLength = getLengthFor(resource);
 		long start = getRangeStart(contentLength);
 		long end = getRangeEnd(contentLength);
-		Assert.isTrue(start < contentLength, "'position' exceeds the resource length " + contentLength);
+		Assert.isTrue(start < contentLength, () -> "'position' exceeds the resource length " + contentLength);
 		return new ResourceRegion(resource, start, end - start + 1);
 	}
 

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

@@ -231,7 +231,7 @@ public abstract class Jackson2CodecSupport {
 			JsonView annotation = getAnnotation(param, JsonView.class);
 			if (annotation != null) {
 				Class<?>[] classes = annotation.value();
-				Assert.isTrue(classes.length == 1, JSON_VIEW_HINT_ERROR + param);
+				Assert.isTrue(classes.length == 1, () -> JSON_VIEW_HINT_ERROR + param);
 				hints = (hints != null ? hints : new HashMap<>(1));
 				hints.put(JSON_VIEW_HINT, classes[0]);
 			}

spring-web/src/main/java/org/springframework/http/converter/BufferedImageHttpMessageConverter.java

@@ -128,7 +128,7 @@ public class BufferedImageHttpMessageConverter implements HttpMessageConverter<B
 	 */
 	public void setCacheDir(File cacheDir) {
 		Assert.notNull(cacheDir, "'cacheDir' must not be null");
-		Assert.isTrue(cacheDir.isDirectory(), "'cacheDir' is not a directory");
+		Assert.isTrue(cacheDir.isDirectory(), () -> "'cacheDir' is not a directory: " + cacheDir);
 		this.cacheDir = cacheDir;
 	}
 

spring-web/src/main/java/org/springframework/http/converter/FormHttpMessageConverter.java

@@ -436,7 +436,7 @@ public class FormHttpMessageConverter implements HttpMessageConverter<MultiValue
 		StringBuilder builder = new StringBuilder();
 		formData.forEach((name, values) -> {
 				if (name == null) {
-					Assert.isTrue(CollectionUtils.isEmpty(values), "Null name in form data: " + formData);
+					Assert.isTrue(CollectionUtils.isEmpty(values), () -> "Null name in form data: " + formData);
 					return;
 				}
 				values.forEach(value -> {

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -93,7 +93,7 @@ class DefaultServerHttpRequestBuilder implements ServerHttpRequest.Builder {
 
 	@Override
 	public ServerHttpRequest.Builder path(String path) {
-		Assert.isTrue(path.startsWith("/"), "The path does not have a leading slash.");
+		Assert.isTrue(path.startsWith("/"), () -> "The path does not have a leading slash: " + path);
 		this.uriPath = path;
 		return this;
 	}

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

@@ -90,7 +90,7 @@ class ServletServerHttpRequest extends AbstractServerHttpRequest {
 		super(initUri(request), request.getContextPath() + servletPath, initHeaders(headers, request));
 
 		Assert.notNull(bufferFactory, "'bufferFactory' must not be null");
-		Assert.isTrue(bufferSize > 0, "'bufferSize' must be higher than 0");
+		Assert.isTrue(bufferSize > 0, "'bufferSize' must be greater than 0");
 
 		this.request = request;
 		this.bufferFactory = bufferFactory;

spring-web/src/main/java/org/springframework/web/filter/AbstractRequestLoggingFilter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -209,7 +209,7 @@ public abstract class AbstractRequestLoggingFilter extends OncePerRequestFilter
 	 * @since 3.0
 	 */
 	public void setMaxPayloadLength(int maxPayloadLength) {
-		Assert.isTrue(maxPayloadLength >= 0, "'maxPayloadLength' should be larger than or equal to 0");
+		Assert.isTrue(maxPayloadLength >= 0, "'maxPayloadLength' must be greater than or equal to 0");
 		this.maxPayloadLength = maxPayloadLength;
 	}
 

spring-web/src/main/java/org/springframework/web/filter/RelativeRedirectFilter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -53,7 +53,7 @@ public class RelativeRedirectFilter extends OncePerRequestFilter {
 	 */
 	public void setRedirectStatus(HttpStatus status) {
 		Assert.notNull(status, "Property 'redirectStatus' is required");
-		Assert.isTrue(status.is3xxRedirection(), "Not a redirect status code");
+		Assert.isTrue(status.is3xxRedirection(), () -> "Not a redirect status code: " + status);
 		this.redirectStatus = status;
 	}
 

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

@@ -205,12 +205,12 @@ public class UrlPathHelper {
 	 * Return a previously {@link #getLookupPathForRequest resolved} lookupPath.
 	 * @param request the current request
 	 * @return the previously resolved lookupPath
-	 * @throws IllegalArgumentException if the not found
+	 * @throws IllegalArgumentException if the lookup path is not found
 	 * @since 5.3
 	 */
 	public static String getResolvedLookupPath(ServletRequest request) {
 		String lookupPath = (String) request.getAttribute(PATH_ATTRIBUTE);
-		Assert.notNull(lookupPath, "Expected lookupPath in request attribute \"" + PATH_ATTRIBUTE + "\".");
+		Assert.notNull(lookupPath, () -> "Expected lookupPath in request attribute \"" + PATH_ATTRIBUTE + "\".");
 		return lookupPath;
 	}
 

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -31,8 +31,8 @@ import org.springframework.web.server.ServerWebExchange;
  * ensure all conditions match a given request.
  *
  * <p>When {@code CompositeRequestCondition} instances are combined or compared
- * they are expected to (a) contain the same number of conditions and (b) that
+ * is expected that (a) they contain the same number of conditions and (b)
- * conditions in the respective index are of the same type. It is acceptable to
+ * conditions at the same index are of the same type. It is acceptable to
  * provide {@code null} conditions or no conditions at all to the constructor.
  *
  * @author Rossen Stoyanchev
@@ -105,7 +105,7 @@ public class CompositeRequestCondition extends AbstractRequestCondition<Composit
 
 	/**
 	 * If one instance is empty, return the other.
-	 * If both instances have conditions, combine the individual conditions
+	 * <p>If both instances have conditions, combine the individual conditions
 	 * after ensuring they are of the same type and number.
 	 */
 	@Override
@@ -131,7 +131,7 @@ public class CompositeRequestCondition extends AbstractRequestCondition<Composit
 
 	private void assertNumberOfConditions(CompositeRequestCondition other) {
 		Assert.isTrue(getLength() == other.getLength(),
-				"Cannot combine CompositeRequestConditions with a different number of conditions. " +
+				() -> "Cannot combine CompositeRequestConditions with a different number of conditions. " +
 				ObjectUtils.nullSafeToString(this.requestConditions) + " and " +
 				ObjectUtils.nullSafeToString(other.requestConditions));
 	}

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

@@ -97,7 +97,7 @@ public class RedirectView extends AbstractUrlBasedView {
 	 * {@link HttpStatus#PERMANENT_REDIRECT}.
 	 */
 	public void setStatusCode(HttpStatus statusCode) {
-		Assert.isTrue(statusCode.is3xxRedirection(), "Not a redirect status code");
+		Assert.isTrue(statusCode.is3xxRedirection(), () -> "Not a redirect status code: " + statusCode);
 		this.statusCode = statusCode;
 	}
 

spring-webflux/src/main/java/org/springframework/web/reactive/socket/CloseStatus.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -154,7 +154,7 @@ public final class CloseStatus {
 	 * @param reason the reason
 	 */
 	public CloseStatus(int code, @Nullable String reason) {
-		Assert.isTrue((code >= 1000 && code < 5000), "Invalid status code");
+		Assert.isTrue((code >= 1000 && code < 5000), () -> "Invalid status code: " + code);
 		this.code = code;
 		this.reason = reason;
 	}

spring-webmvc/src/main/java/org/springframework/web/servlet/config/annotation/RedirectViewControllerRegistration.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -54,7 +54,7 @@ public class RedirectViewControllerRegistration {
 	 * will select {@code HttpStatus.MOVED_TEMPORARILY (302)} by default.
 	 */
 	public RedirectViewControllerRegistration setStatusCode(HttpStatus statusCode) {
-		Assert.isTrue(statusCode.is3xxRedirection(), "Not a redirect status code");
+		Assert.isTrue(statusCode.is3xxRedirection(), () -> "Not a redirect status code: " + statusCode);
 		this.redirectView.setStatusCode(statusCode);
 		return this;
 	}

spring-webmvc/src/main/java/org/springframework/web/servlet/mvc/condition/CompositeRequestCondition.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -133,7 +133,7 @@ public class CompositeRequestCondition extends AbstractRequestCondition<Composit
 
 	private void assertNumberOfConditions(CompositeRequestCondition other) {
 		Assert.isTrue(getLength() == other.getLength(),
-				"Cannot combine CompositeRequestConditions with a different number of conditions. " +
+				() -> "Cannot combine CompositeRequestConditions with a different number of conditions. " +
 				ObjectUtils.nullSafeToString(this.requestConditions) + " and " +
 				ObjectUtils.nullSafeToString(other.requestConditions));
 	}

spring-websocket/src/main/java/org/springframework/web/socket/CloseStatus.java

@@ -168,7 +168,7 @@ public final class CloseStatus implements Serializable {
 	 * @param reason the reason
 	 */
 	public CloseStatus(int code, @Nullable String reason) {
-		Assert.isTrue((code >= 1000 && code < 5000), "Invalid status code");
+		Assert.isTrue((code >= 1000 && code < 5000), () -> "Invalid status code: " + code);
 		this.code = code;
 		this.reason = reason;
 	}