[prone] Add error-prone.picnic.tech featuring RedundantStringConversion

build.gradle

@@ -17,6 +17,7 @@ ext {
 description = "Spring Framework"
 
 configure(allprojects) { project ->
+    apply from: rootProject.file('gradle/error-prone.gradle')
 	apply plugin: "org.springframework.build.localdev"
 	group = "org.springframework"
 	repositories {

gradle/error-prone.gradle

@@ -0,0 +1,21 @@
+import static java.lang.System.getenv
+
+apply plugin: 'net.ltgt.errorprone'
+
+dependencies {
+	errorprone('com.google.errorprone:error_prone_core:2.42.0')
+	errorprone('tech.picnic.error-prone-support:error-prone-contrib:0.25.0')
+}
+
+tasks.withType(JavaCompile).configureEach {
+	options.errorprone {
+		disableAllChecks = true // remove once applied error-prone. # https://github.com/google/error-prone/issues/5280
+		error('RedundantStringConversion')
+		if (!getenv().containsKey('CI') && getenv('IN_PLACE')?.toBoolean()) {
+			errorproneArgs.addAll(
+					'-XepPatchLocation:IN_PLACE',
+					'-XepPatchChecks:RedundantStringConversion'
+					)
+		}
+	}
+}

spring-aop/src/main/java/org/springframework/aop/aspectj/MethodInvocationProceedingJoinPoint.java

@@ -166,7 +166,7 @@ public String toLongString() {
 
 	@Override
 	public String toString() {
-		return "execution(" + getSignature().toString() + ")";
+		return "execution(" + getSignature() + ")";
 	}
 
 

spring-beans/src/main/java/org/springframework/beans/factory/config/YamlProcessor.java

@@ -249,7 +249,7 @@ private Map<String, Object> asMap(Object object) {
 			}
 			else {
 				// It has to be a map key in this case
-				result.put("[" + key.toString() + "]", value);
+				result.put("[" + key + "]", value);
 			}
 		});
 		return result;

spring-context-indexer/src/main/java/org/springframework/context/index/processor/TypeHelper.java

@@ -63,7 +63,7 @@ public String getType(TypeMirror type) {
 		if (type instanceof DeclaredType declaredType) {
 			Element enclosingElement = declaredType.asElement().getEnclosingElement();
 			if (enclosingElement instanceof TypeElement) {
-				return getQualifiedName(enclosingElement) + "$" + declaredType.asElement().getSimpleName().toString();
+				return getQualifiedName(enclosingElement) + "$" + declaredType.asElement().getSimpleName();
 			}
 			else {
 				return getQualifiedName(declaredType.asElement());

spring-context-support/src/main/java/org/springframework/mail/MailSendException.java

@@ -137,7 +137,7 @@ public final Exception[] getMessageExceptions() {
 			sb.append("Failed messages: ");
 			for (int i = 0; i < this.messageExceptions.length; i++) {
 				Exception subEx = this.messageExceptions[i];
-				sb.append(subEx.toString());
+				sb.append(subEx);
 				if (i < this.messageExceptions.length - 1) {
 					sb.append("; ");
 				}

spring-context/src/main/java/org/springframework/cache/annotation/SpringCacheAnnotationParser.java

@@ -198,13 +198,13 @@ private void parseCachingAnnotation(
 	private void validateCacheOperation(AnnotatedElement ae, CacheOperation operation) {
 		if (StringUtils.hasText(operation.getKey()) && StringUtils.hasText(operation.getKeyGenerator())) {
 			throw new IllegalStateException("Invalid cache annotation configuration on '" +
-					ae.toString() + "'. Both 'key' and 'keyGenerator' attributes have been set. " +
+					ae + "'. Both 'key' and 'keyGenerator' attributes have been set. " +
 					"These attributes are mutually exclusive: either set the SpEL expression used to" +
 					"compute the key at runtime or set the name of the KeyGenerator bean to use.");
 		}
 		if (StringUtils.hasText(operation.getCacheManager()) && StringUtils.hasText(operation.getCacheResolver())) {
 			throw new IllegalStateException("Invalid cache annotation configuration on '" +
-					ae.toString() + "'. Both 'cacheManager' and 'cacheResolver' attributes have been set. " +
+					ae + "'. Both 'cacheManager' and 'cacheResolver' attributes have been set. " +
 					"These attributes are mutually exclusive: the cache manager is used to configure a" +
 					"default cache resolver if none is set. If a cache resolver is set, the cache manager" +
 					"won't be used.");

spring-context/src/main/java/org/springframework/cache/config/CacheAdviceParser.java

@@ -222,7 +222,7 @@ <T extends CacheOperation.Builder> T merge(Element element, ReaderContext reader
 
 			if (StringUtils.hasText(builder.getKey()) && StringUtils.hasText(builder.getKeyGenerator())) {
 				throw new IllegalStateException("Invalid cache advice configuration on '" +
-						element.toString() + "'. Both 'key' and 'keyGenerator' attributes have been set. " +
+						element + "'. Both 'key' and 'keyGenerator' attributes have been set. " +
 						"These attributes are mutually exclusive: either set the SpEL expression used to" +
 						"compute the key at runtime or set the name of the KeyGenerator bean to use.");
 			}

spring-context/src/main/java/org/springframework/instrument/classloading/InstrumentationLoadTimeWeaver.java

@@ -191,7 +191,7 @@ public FilteringClassFileTransformer(
 
 		@Override
 		public String toString() {
-			return "FilteringClassFileTransformer for: " + this.targetTransformer.toString();
+			return "FilteringClassFileTransformer for: " + this.targetTransformer;
 		}
 	}
 

spring-core/src/main/java/org/springframework/cglib/proxy/MethodInterceptorGenerator.java

@@ -145,7 +145,7 @@ public void generate(ClassEmitter ce, Context context, List methods) {
     private static void superHelper(CodeEmitter e, MethodInfo method, Context context)
     {
         if (TypeUtils.isAbstract(method.getModifiers())) {
-            e.throw_exception(ABSTRACT_METHOD_ERROR, method.toString() + " is abstract" );
+            e.throw_exception(ABSTRACT_METHOD_ERROR, method + " is abstract" );
         } else {
             e.load_this();
             context.emitLoadArgsAndInvoke(e, method);

spring-core/src/main/java/org/springframework/cglib/transform/ClassTransformerChain.java

@@ -53,7 +53,7 @@ public String toString() {
             if (i > 0) {
                 sb.append(", ");
             }
-            sb.append(chain[i].toString());
+            sb.append(chain[i]);
         }
         sb.append("}");
         return sb.toString();

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

@@ -246,7 +246,7 @@ else if (this.dimensions != null) {
 			for (int i = 1; i < count; i++) {
 				sj.add(getChild(i).toStringAST());
 			}
-			sb.append(sj.toString());
+			sb.append(sj);
 		}
 
 		return sb.toString();

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

@@ -468,7 +468,7 @@ private String appendPayload(Object payload) {
 		}
 		byte[] bytes = (byte[]) payload;
 		MimeType mimeType = getContentType();
-		String contentType = (mimeType != null ? " " + mimeType.toString() : "");
+		String contentType = (mimeType != null ? " " + mimeType : "");
 		if (bytes.length == 0 || mimeType == null || !isReadableContentType()) {
 			return contentType;
 		}

spring-messaging/src/main/java/org/springframework/messaging/support/MessageHeaderAccessor.java

@@ -480,7 +480,7 @@ public void setErrorChannel(MessageChannel errorChannel) {
 	 * @return the message
 	 */
 	public String getShortLogMessage(Object payload) {
-		return "headers=" + this.headers.toString() + getShortPayloadLogMessage(payload);
+		return "headers=" + this.headers + getShortPayloadLogMessage(payload);
 	}
 
 	/**
@@ -489,7 +489,7 @@ public String getShortLogMessage(Object payload) {
 	 * @return the message
 	 */
 	public String getDetailedLogMessage(@Nullable Object payload) {
-		return "headers=" + this.headers.toString() + getDetailedPayloadLogMessage(payload);
+		return "headers=" + this.headers + getDetailedPayloadLogMessage(payload);
 	}
 
 	protected String getShortPayloadLogMessage(Object payload) {

spring-orm/src/main/java/org/springframework/orm/jpa/support/OpenEntityManagerInViewInterceptor.java

@@ -143,7 +143,7 @@ public void afterConcurrentHandlingStarted(WebRequest request) {
 	 * @see #PARTICIPATE_SUFFIX
 	 */
 	protected String getParticipateAttributeName() {
-		return obtainEntityManagerFactory().toString() + PARTICIPATE_SUFFIX;
+		return obtainEntityManagerFactory() + PARTICIPATE_SUFFIX;
 	}
 
 

spring-r2dbc/src/main/java/org/springframework/r2dbc/core/binding/BindMarkersFactoryResolver.java

@@ -160,7 +160,7 @@ private static String filterBindMarker(CharSequence input) {
 			if (builder.isEmpty()) {
 				return "";
 			}
-			return "_" + builder.toString();
+			return "_" + builder;
 		}
 	}
 

spring-test/src/main/java/org/springframework/test/web/client/AbstractRequestExpectationManager.java

@@ -174,7 +174,7 @@ protected String getRequestDetails() {
 		if (!this.requests.isEmpty()) {
 			sb.append(":\n");
 			for (ClientHttpRequest request : this.requests) {
-				sb.append(request.toString()).append('\n');
+				sb.append(request).append('\n');
 			}
 		}
 		else {

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

@@ -133,7 +133,7 @@ public static URI initURI(HttpServletRequest servletRequest) {
 				try {
 					// Maybe malformed query, try to parse and encode it
 					query = UriComponentsBuilder.fromUriString("?" + query).build().toUri().getRawQuery();
-					return new URI(servletRequest.getRequestURL().toString() + "?" + query);
+					return new URI(servletRequest.getRequestURL() + "?" + query);
 				}
 				catch (URISyntaxException ex2) {
 					try {

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

@@ -142,7 +142,7 @@ private static URI initUri(HttpServletRequest servletRequest) {
 				try {
 					// Maybe malformed query, try to parse and encode it
 					query = UriComponentsBuilder.fromUriString("?" + query).build().toUri().getRawQuery();
-					return new URI(servletRequest.getRequestURL().toString() + "?" + query);
+					return new URI(servletRequest.getRequestURL() + "?" + query);
 				}
 				catch (URISyntaxException ex2) {
 					try {

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

@@ -223,7 +223,7 @@ public List<String> getPathSegments() {
 						}
 						queryBuilder.append(name);
 						if (value != null) {
-							queryBuilder.append('=').append(value.toString());
+							queryBuilder.append('=').append(value);
 						}
 					}
 				}

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

@@ -1278,7 +1278,7 @@ else if (p.processCurlyBrackets(c)) {
 				}
 				// Otherwise, port-invalid validation error, return failure.
 				else {
-					p.failure("Invalid port: \"" + Character.toString(c) + "\"");
+					p.failure("Invalid port: \"" + c + "\"");
 				}
 			}
 		},
@@ -2703,7 +2703,7 @@ else if (c == ':') {
 				// IPv6-invalid-code-point validation error, return failure.
 				else if (c != EOF) {
 					throw new InvalidUrlException(
-							"IPv6 address contains \"" + Character.toString(c) + "\", which is " +
+							"IPv6 address contains \"" + c + "\", which is " +
 									"neither an ASCII hex digit nor a ':'.");
 				}
 				// Set address[pieceIndex] to value.

spring-webflux/src/main/java/org/springframework/web/reactive/function/UnsupportedMediaTypeException.java

@@ -73,7 +73,7 @@ public UnsupportedMediaTypeException(@Nullable MediaType contentType, List<Media
 
 	private static String initReason(@Nullable MediaType contentType, @Nullable ResolvableType bodyType) {
 		return "Content type '" + (contentType != null ? contentType : "") + "' not supported" +
-				(bodyType != null ? " for bodyType=" + bodyType.toString() : "");
+				(bodyType != null ? " for bodyType=" + bodyType : "");
 	}
 
 

spring-webflux/src/main/java/org/springframework/web/reactive/function/server/RequestPredicates.java

@@ -1142,7 +1142,7 @@ public void changeParser(PathPatternParser parser) {
 
 		@Override
 		public String toString() {
-			return "!" + this.delegate.toString();
+			return "!" + this.delegate;
 		}
 	}
 

spring-webmvc/src/main/java/org/springframework/web/servlet/view/ContentNegotiatingViewResolver.java

@@ -228,7 +228,7 @@ public void afterPropertiesSet() {
 		}
 
 		String mediaTypeInfo = (logger.isDebugEnabled() && requestedMediaTypes != null ?
-				" given " + requestedMediaTypes.toString() : "");
+				" given " + requestedMediaTypes : "");
 
 		if (this.useNotAcceptableStatusCode) {
 			if (logger.isDebugEnabled()) {