Explore reduced configuration extension.

Do not register a MappingContext through the extension, instead expose a MappingContext through KeyValueAdapter so implementations can bring their own mapping context. They can also decide where to obtain the mapping context from and whether to expose it as bean at all. This is useful for a minimal configuration and removes the need to detect whether there is already a mapping context available.

Detection of mapping context (or even converters) can go either into the adapter or somewhere else as detecting bean registrations depends on configuration ordering. Any later bean registrations might be not visible to our extension and so we had always the drawback of requiring any customizations being colocated within the config class that uses the Enable…Repositories annotation.

Author: mp911de

src/main/java/org/springframework/data/keyvalue/core/KeyValueAdapter.java

@@ -20,7 +20,10 @@
 
 import org.jspecify.annotations.Nullable;
 import org.springframework.beans.factory.DisposableBean;
+import org.springframework.data.keyvalue.core.mapping.KeyValuePersistentEntity;
+import org.springframework.data.keyvalue.core.mapping.KeyValuePersistentProperty;
 import org.springframework.data.keyvalue.core.query.KeyValueQuery;
+import org.springframework.data.mapping.context.MappingContext;
 import org.springframework.data.util.CloseableIterator;
 
 /**
@@ -32,6 +35,14 @@
  */
 public interface KeyValueAdapter extends DisposableBean {
 
+	/**
+	 * Expose the {@link MappingContext} to obtain mapping metadata.
+	 *
+	 * @return the used mapping context.
+	 * @since 4.0
+	 */
+	MappingContext<? extends KeyValuePersistentEntity<?, ?>, ? extends KeyValuePersistentProperty<?>> getMappingContext();
+
 	/**
 	 * Add object with given id to keyspace.
 	 *

src/main/java/org/springframework/data/keyvalue/core/KeyValueTemplate.java

@@ -70,38 +70,24 @@ public class KeyValueTemplate implements KeyValueOperations, ApplicationEventPub
 	 * @param adapter must not be {@literal null}.
 	 */
 	public KeyValueTemplate(KeyValueAdapter adapter) {
-		this(adapter, new KeyValueMappingContext<>());
+		this(adapter, DefaultIdentifierGenerator.INSTANCE);
 	}
 
 	/**
-	 * Create new {@link KeyValueTemplate} using the given {@link KeyValueAdapter} and {@link MappingContext}.
+	 * Create new {@link KeyValueTemplate} using the given {@link KeyValueAdapter} and {@link IdentifierGenerator}.
 	 *
 	 * @param adapter must not be {@literal null}.
-	 * @param mappingContext must not be {@literal null}.
-	 */
-	public KeyValueTemplate(KeyValueAdapter adapter,
-			MappingContext<? extends KeyValuePersistentEntity<?, ?>, ? extends KeyValuePersistentProperty<?>> mappingContext) {
-		this(adapter, mappingContext, DefaultIdentifierGenerator.INSTANCE);
-	}
-
-	/**
-	 * Create new {@link KeyValueTemplate} using the given {@link KeyValueAdapter} and {@link MappingContext}.
-	 *
-	 * @param adapter must not be {@literal null}.
-	 * @param mappingContext must not be {@literal null}.
 	 * @param identifierGenerator must not be {@literal null}.
-	 * @since 2.4
+	 * @since 4.0
 	 */
 	public KeyValueTemplate(KeyValueAdapter adapter,
-			MappingContext<? extends KeyValuePersistentEntity<?, ?>, ? extends KeyValuePersistentProperty<?>> mappingContext,
 			IdentifierGenerator identifierGenerator) {
 
 		Assert.notNull(adapter, "Adapter must not be null");
-		Assert.notNull(mappingContext, "MappingContext must not be null");
 		Assert.notNull(identifierGenerator, "IdentifierGenerator must not be null");
 
 		this.adapter = adapter;
-		this.mappingContext = mappingContext;
+		this.mappingContext = adapter.getMappingContext();
 		this.identifierGenerator = identifierGenerator;
 	}
 

src/main/java/org/springframework/data/keyvalue/repository/config/KeyValueRepositoryConfigurationExtension.java

@@ -21,14 +21,14 @@
 import java.util.Optional;
 
 import org.jspecify.annotations.Nullable;
+
 import org.springframework.beans.factory.support.AbstractBeanDefinition;
 import org.springframework.beans.factory.support.BeanDefinitionBuilder;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
 import org.springframework.beans.factory.support.RootBeanDefinition;
 import org.springframework.core.annotation.AnnotationAttributes;
 import org.springframework.core.annotation.MergedAnnotation;
 import org.springframework.core.type.AnnotationMetadata;
-import org.springframework.data.keyvalue.core.mapping.context.KeyValueMappingContext;
 import org.springframework.data.keyvalue.repository.KeyValueRepository;
 import org.springframework.data.keyvalue.repository.query.KeyValuePartTreeQuery;
 import org.springframework.data.keyvalue.repository.query.SpelQueryCreator;
@@ -47,7 +47,6 @@
  */
 public abstract class KeyValueRepositoryConfigurationExtension extends RepositoryConfigurationExtensionSupport {
 
-	protected static final String MAPPING_CONTEXT_BEAN_NAME = "keyValueMappingContext";
 	protected static final String KEY_VALUE_TEMPLATE_BEAN_REF_ATTRIBUTE = "keyValueTemplateRef";
 
 	@Override
@@ -78,7 +77,6 @@ public void postProcess(BeanDefinitionBuilder builder, AnnotationRepositoryConfi
 		builder.addPropertyReference("keyValueOperations", attributes.getString(KEY_VALUE_TEMPLATE_BEAN_REF_ATTRIBUTE));
 		builder.addPropertyValue("queryCreator", getQueryCreatorType(config));
 		builder.addPropertyValue("queryType", getQueryType(config));
-		builder.addPropertyReference("mappingContext", getMappingContextBeanRef());
 	}
 
 	/**
@@ -128,15 +126,6 @@ public void registerBeansForRoot(BeanDefinitionRegistry registry, RepositoryConf
 
 		super.registerBeansForRoot(registry, configurationSource);
 
-		registerIfNotAlreadyRegistered(() -> {
-
-			RootBeanDefinition mappingContext = new RootBeanDefinition(KeyValueMappingContext.class);
-			mappingContext.setSource(configurationSource.getSource());
-
-			return mappingContext;
-
-		}, registry, getMappingContextBeanRef(), configurationSource);
-
 		Optional<String> keyValueTemplateName = configurationSource.getAttribute(KEY_VALUE_TEMPLATE_BEAN_REF_ATTRIBUTE);
 
 		// No custom template reference configured and no matching bean definition found
@@ -174,15 +163,4 @@ public void registerBeansForRoot(BeanDefinitionRegistry registry, RepositoryConf
 	 */
 	protected abstract String getDefaultKeyValueTemplateRef();
 
-	/**
-	 * Returns the {@link org.springframework.data.mapping.context.MappingContext} bean name to potentially register a
-	 * default mapping context bean if no bean is registered with the returned name. Defaults to
-	 * {@link MAPPING_CONTEXT_BEAN_NAME}.
-	 *
-	 * @return the {@link org.springframework.data.mapping.context.MappingContext} bean name. Never {@literal null}.
-	 * @since 2.0
-	 */
-	protected String getMappingContextBeanRef() {
-		return MAPPING_CONTEXT_BEAN_NAME;
-	}
 }

src/main/java/org/springframework/data/map/MapKeyValueAdapter.java

@@ -28,6 +28,9 @@
 import org.springframework.data.keyvalue.core.KeyValueAdapter;
 import org.springframework.data.keyvalue.core.QueryEngine;
 import org.springframework.data.keyvalue.core.SortAccessor;
+import org.springframework.data.keyvalue.core.mapping.KeyValuePersistentEntity;
+import org.springframework.data.keyvalue.core.mapping.KeyValuePersistentProperty;
+import org.springframework.data.keyvalue.core.mapping.context.KeyValueMappingContext;
 import org.springframework.data.util.CloseableIterator;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
@@ -38,12 +41,14 @@
  * @author Christoph Strobl
  * @author Derek Cochran
  * @author Marcel Overdijk
+ * @author Mark Paluch
  */
 public class MapKeyValueAdapter extends AbstractKeyValueAdapter {
 
 	@SuppressWarnings("rawtypes") //
 	private final Class<? extends Map> keySpaceMapType;
 	private final Map<String, Map<Object, Object>> store;
+	private KeyValueMappingContext<? extends KeyValuePersistentEntity<?, ?>, ? extends KeyValuePersistentProperty<?>> mappingContext = new KeyValueMappingContext<>();
 
 	/**
 	 * Create new {@link MapKeyValueAdapter} using {@link ConcurrentHashMap} as backing store type.
@@ -143,6 +148,16 @@ private MapKeyValueAdapter(Map<String, Map<Object, Object>> store, Class<? exten
 		this.keySpaceMapType = keySpaceMapType;
 	}
 
+	@Override
+	public KeyValueMappingContext<? extends KeyValuePersistentEntity<?, ?>, ? extends KeyValuePersistentProperty<?>> getMappingContext() {
+		return mappingContext;
+	}
+
+	public void setMappingContext(
+			KeyValueMappingContext<? extends KeyValuePersistentEntity<?, ?>, ? extends KeyValuePersistentProperty<?>> mappingContext) {
+		this.mappingContext = mappingContext;
+	}
+
 	@Override
 	public @Nullable Object put(Object id, Object item, String keyspace) {
 

src/test/java/org/springframework/data/keyvalue/core/KeyValueTemplateUnitTests.java

@@ -47,6 +47,7 @@
 import org.springframework.data.keyvalue.core.event.KeyValueEvent.BeforeGetEvent;
 import org.springframework.data.keyvalue.core.event.KeyValueEvent.BeforeInsertEvent;
 import org.springframework.data.keyvalue.core.event.KeyValueEvent.BeforeUpdateEvent;
+import org.springframework.data.keyvalue.core.mapping.context.KeyValueMappingContext;
 import org.springframework.data.keyvalue.core.query.KeyValueQuery;
 
 /**
@@ -73,6 +74,7 @@ class KeyValueTemplateUnitTests {
 
 	@BeforeEach
 	void setUp() {
+		when(adapterMock.getMappingContext()).thenReturn(new KeyValueMappingContext());
 		this.template = new KeyValueTemplate(adapterMock);
 		this.template.setApplicationEventPublisher(publisherMock);
 	}

src/test/java/org/springframework/data/map/repository/config/MapRepositoriesConfigurationExtensionIntegrationTests.java

@@ -44,6 +44,7 @@
 import org.springframework.data.keyvalue.core.QueryEngineFactory;
 import org.springframework.data.keyvalue.core.SortAccessor;
 import org.springframework.data.keyvalue.core.SpelQueryEngine;
+import org.springframework.data.keyvalue.core.mapping.context.KeyValueMappingContext;
 import org.springframework.data.keyvalue.core.query.KeyValueQuery;
 import org.springframework.data.keyvalue.repository.KeyValueRepository;
 import org.springframework.data.keyvalue.repository.query.PredicateQueryCreator;
@@ -220,7 +221,7 @@ public KeyValueOperations mapKeyValueTemplate() {
 		public KeyValueAdapter keyValueAdapter() {
 
 			KeyValueAdapter mock = mock(KeyValueAdapter.class);
-
+			when(mock.getMappingContext()).thenReturn(new KeyValueMappingContext());
 			when(mock.get(any(), anyString(), any())).thenThrow(new IllegalStateException("Mock"));
 
 			return mock;