Rename RepositoryMethodMetadata and move it to an interceptor.

Rename RepositoryMethodMetadata to RepositoryMethodContext.
Add flags to enable method metadata exposure.

See: #3090
Original Pull Request: #3093

Author: mp911de

Diff for: src/main/antora/modules/ROOT/pages/repositories/custom-implementations.adoc

@@ -269,7 +269,7 @@ package com.acme.search;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.data.domain.Limit;
-import org.springframework.data.repository.core.support.RepositoryMethodMetadata;
+import org.springframework.data.repository.core.support.RepositoryMethodContext;
 
 class DefaultSearchExtension<T> implements SearchExtension<T> {
 
@@ -280,12 +280,12 @@ class DefaultSearchExtension<T> implements SearchExtension<T> {
     }
 
     public List<T> search(String text, Limit limit) {
-        return search(RepositoryMethodMetadata.get(), text, limit);
+        return search(RepositoryMethodContext.currentMethod(), text, limit);
     }
 
-    List<T> search(RepositoryMethodMetadata metadata, String text, Limit limit) {
+    List<T> search(RepositoryMethodContext metadata, String text, Limit limit) {
 
-        Class<T> domainType = metadata.repository().getDomainType();
+        Class<T> domainType = metadata.getRepository().getDomainType();
 
         String indexName = domainType.getSimpleName().toLowerCase();
         List<String> jsonResult = service.search(indexName, text, 0, limit.max());
@@ -312,7 +312,8 @@ com.acme.search.SearchExtension=com.acme.search.DefaultSearchExtension
 ----
 ====
 
-To make use of the extension simply add the interface to the repository as shown below. The infrastructure will take care placing the required `RepositoryMethodMetadata` so all that
+To make use of the extension simply add the interface to the repository as shown below.
+The infrastructure will take care placing the required `RepositoryMethodContext` so all that
 
 ====
 [source,java]

Diff for: src/main/java/org/springframework/data/repository/core/support/DefaultRepositoryMethodContext.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2024 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.repository.core.support;
+
+import java.lang.reflect.Method;
+
+import org.springframework.core.NamedThreadLocal;
+import org.springframework.data.repository.core.RepositoryMetadata;
+import org.springframework.lang.Nullable;
+
+/**
+ * Class containing value objects providing information about the current repository method invocation.
+ *
+ * @author Christoph Strobl
+ * @author Mark Paluch
+ */
+class DefaultRepositoryMethodContext implements RepositoryMethodContext {
+
+	/**
+	 * ThreadLocal holder for repository method associated with this thread. Will contain {@code null} unless the
+	 * "exposeMetadata" property on the controlling repository factory configuration has been set to "true".
+	 */
+	private static final ThreadLocal<RepositoryMethodContext> currentMethod = new NamedThreadLocal<>(
+			"Current Repository Method");
+
+	private final RepositoryMetadata repositoryMetadata;
+	private final Method method;
+
+	public DefaultRepositoryMethodContext(RepositoryMetadata repositoryMetadata, Method method) {
+		this.repositoryMetadata = repositoryMetadata;
+		this.method = method;
+	}
+
+	@Nullable
+	public static RepositoryMethodContext getMetadata() {
+		return currentMethod.get();
+	}
+
+	@Nullable
+	public static RepositoryMethodContext setMetadata(@Nullable RepositoryMethodContext metadata) {
+
+		RepositoryMethodContext old = currentMethod.get();
+		if (metadata != null) {
+			currentMethod.set(metadata);
+		} else {
+			currentMethod.remove();
+		}
+
+		return old;
+	}
+
+	@Override
+	public RepositoryMetadata getRepository() {
+		return repositoryMetadata;
+	}
+
+	@Override
+	public Method getMethod() {
+		return method;
+	}
+
+}

Diff for: src/main/java/org/springframework/data/repository/core/support/DefaultRepositoryMethodMetadata.java

@@ -33,7 +33,6 @@
 import org.springframework.data.repository.core.RepositoryInformation;
 import org.springframework.data.repository.core.support.RepositoryInvocationMulticaster.DefaultRepositoryInvocationMulticaster;
 import org.springframework.data.repository.core.support.RepositoryInvocationMulticaster.NoOpRepositoryInvocationMulticaster;
-import org.springframework.data.repository.core.support.RepositoryMethodMetadata.MethodMetadata;
 import org.springframework.data.repository.query.QueryCreationException;
 import org.springframework.data.repository.query.QueryLookupStrategy;
 import org.springframework.data.repository.query.QueryMethod;
@@ -164,9 +163,7 @@ private Object doInvoke(MethodInvocation invocation) throws Throwable {
 			RepositoryMethodInvoker invocationMetadata = invocationMetadataCache.get(method);
 
 			if (invocationMetadata == null) {
-
-				DefaultRepositoryMethodMetadata repositoryMethodMetadata = DefaultRepositoryMethodMetadata.repositoryMethodMetadata(repositoryInformation, method);
-				invocationMetadata = RepositoryMethodInvoker.forRepositoryQuery(repositoryMethodMetadata, queries.get(method));
+				invocationMetadata = RepositoryMethodInvoker.forRepositoryQuery(method, queries.get(method));
 				invocationMetadataCache.put(method, invocationMetadata);
 			}
 

Diff for: src/main/java/org/springframework/data/repository/core/support/QueryExecutorMethodInterceptor.java

@@ -32,7 +32,6 @@
 import org.springframework.data.repository.core.RepositoryMetadata;
 import org.springframework.data.repository.core.support.MethodLookup.InvokedMethod;
 import org.springframework.data.repository.core.support.RepositoryInvocationMulticaster.NoOpRepositoryInvocationMulticaster;
-import org.springframework.data.repository.core.support.RepositoryMethodMetadata.MethodMetadata;
 import org.springframework.data.repository.util.ReactiveWrapperConverters;
 import org.springframework.data.util.ReactiveWrappers;
 import org.springframework.data.util.Streamable;
@@ -282,7 +281,7 @@ Object invoke(RepositoryInvocationMulticaster listener, Method method, Object[]
 
 		ReflectionUtils.makeAccessible(methodToCall);
 
-		return fragments.invoke(metadata, listener,
+		return fragments.invoke(metadata != null ? metadata.getRepositoryInterface() : method.getDeclaringClass(), listener,
 				method, methodToCall, argumentConverter.apply(methodToCall, args));
 	}
 
@@ -370,6 +369,7 @@ public static class RepositoryFragments implements Streamable<RepositoryFragment
 		private final List<RepositoryFragment<?>> fragments;
 
 		private RepositoryFragments(List<RepositoryFragment<?>> fragments) {
+
 			this.fragments = fragments;
 		}
 
@@ -382,10 +382,6 @@ public static RepositoryFragments empty() {
 			return EMPTY;
 		}
 
-		public static RepositoryFragments empty(RepositoryMetadata metadata) {
-			return EMPTY;
-		}
-
 		/**
 		 * Create {@link RepositoryFragments} from just implementation objects.
 		 *
@@ -488,7 +484,7 @@ public Object invoke(Method invokedMethod, Method methodToCall, Object[] args) t
 		/**
 		 * Invoke {@link Method} by resolving the fragment that implements a suitable method.
 		 *
-		 * @param metadata
+		 * @param repositoryInterface
 		 * @param listener
 		 * @param invokedMethod invoked method as per invocation on the interface.
 		 * @param methodToCall backend method that is backing the call.
@@ -497,7 +493,7 @@ public Object invoke(Method invokedMethod, Method methodToCall, Object[] args) t
 		 * @throws Throwable
 		 */
 		@Nullable
-		Object invoke(@Nullable RepositoryMetadata metadata, RepositoryInvocationMulticaster listener, Method invokedMethod,
+		Object invoke(Class<?> repositoryInterface, RepositoryInvocationMulticaster listener, Method invokedMethod,
 				Method methodToCall, Object[] args) throws Throwable {
 
 			RepositoryFragment<?> fragment = fragmentCache.computeIfAbsent(methodToCall, this::findImplementationFragment);
@@ -511,15 +507,12 @@ Object invoke(@Nullable RepositoryMetadata metadata, RepositoryInvocationMultica
 
 			if (repositoryMethodInvoker == null) {
 
-				DefaultRepositoryMethodMetadata repositoryMethodMetadata = DefaultRepositoryMethodMetadata.repositoryMethodMetadata(metadata, invokedMethod, methodToCall);
-				repositoryMethodInvoker = RepositoryMethodInvoker.forFragmentMethod(repositoryMethodMetadata, optional.get(),
+				repositoryMethodInvoker = RepositoryMethodInvoker.forFragmentMethod(invokedMethod, optional.get(),
 						methodToCall);
-
 				invocationMetadataCache.put(invokedMethod, repositoryMethodInvoker);
 			}
 
-			Class<?> target = (metadata != null && metadata.getRepositoryInterface() != null) ? metadata.getRepositoryInterface() : invokedMethod.getDeclaringClass();
-			return repositoryMethodInvoker.invoke(target, listener, args);
+			return repositoryMethodInvoker.invoke(repositoryInterface, listener, args);
 		}
 
 		private RepositoryFragment<?> findImplementationFragment(Method key) {

Diff for: src/main/java/org/springframework/data/repository/core/support/RepositoryComposition.java

@@ -69,6 +69,7 @@ public abstract class RepositoryFactoryBeanSupport<T extends Repository<S, ID>,
 	private final Class<? extends T> repositoryInterface;
 
 	private RepositoryFactorySupport factory;
+	private boolean exposeMetadata;
 	private Key queryLookupStrategyKey;
 	private Optional<Class<?>> repositoryBaseClass = Optional.empty();
 	private Optional<Object> customImplementation = Optional.empty();
@@ -107,6 +108,18 @@ public void setRepositoryBaseClass(Class<?> repositoryBaseClass) {
 		this.repositoryBaseClass = Optional.ofNullable(repositoryBaseClass);
 	}
 
+	/**
+	 * Set whether the repository method metadata should be exposed by the repository factory as a ThreadLocal for
+	 * retrieval via the {@code RepositoryMethodContext} class. This is useful if an advised object needs to obtain
+	 * repository information.
+	 * <p>
+	 * Default is "false", in order to avoid unnecessary extra interception. This means that no guarantees are provided
+	 * that {@code RepositoryMethodContext} access will work consistently within any method of the advised object.
+	 */
+	public void setExposeMetadata(boolean exposeMetadata) {
+		this.exposeMetadata = exposeMetadata;
+	}
+
 	/**
 	 * Set the {@link QueryLookupStrategy.Key} to be used.
 	 *
@@ -258,6 +271,7 @@ public boolean isSingleton() {
 	public void afterPropertiesSet() {
 
 		this.factory = createRepositoryFactory();
+		this.factory.setExposeMetadata(exposeMetadata);
 		this.factory.setQueryLookupStrategyKey(queryLookupStrategyKey);
 		this.factory.setNamedQueries(namedQueries);
 		this.factory.setEvaluationContextProvider(