DATAJPA-1446 - Clear JpaMetamodel CACHE when application context is closed.

Author: Nowheresly

src/main/java/org/springframework/data/jpa/mapping/JpaMetamodelMappingContext.java

@@ -38,6 +38,7 @@
  * @author Oliver Gierke
  * @author Christoph Strobl
  * @author Mark Paluch
+ * @author Sylvère Richard
  * @since 1.3
  */
 public class JpaMetamodelMappingContext
@@ -90,7 +91,7 @@ protected boolean shouldCreatePersistentEntityFor(TypeInformation<?> type) {
 
 	/**
 	 * We customize the lookup of {@link PersistentPropertyPaths} by also traversing properties that are embeddables.
-	 * 
+	 *
 	 * @see org.springframework.data.mapping.context.AbstractMappingContext#findPersistentPropertyPaths(java.lang.Class,
 	 *      java.util.function.Predicate)
 	 */
@@ -100,7 +101,7 @@ public <T> PersistentPropertyPaths<T, JpaPersistentProperty> findPersistentPrope
 		return doFindPersistentPropertyPaths(type, predicate, it -> it.isEmbeddable());
 	}
 
-	/* 
+	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.mapping.context.AbstractMappingContext#hasPersistentEntityFor(java.lang.Class)
 	 */
@@ -125,7 +126,7 @@ private Metamodels(Set<Metamodel> metamodels) {
 
 		/**
 		 * Returns the {@link JpaMetamodel} for the given type.
-		 * 
+		 *
 		 * @param type must not be {@literal null}.
 		 * @return
 		 */
@@ -139,7 +140,7 @@ public JpaMetamodel getMetamodel(TypeInformation<?> type) {
 
 		/**
 		 * Returns whether the given type is managed by one of the underlying {@link Metamodel} instances.
-		 * 
+		 *
 		 * @param type must not be {@literal null}.
 		 * @return
 		 */
@@ -149,7 +150,7 @@ public boolean isMetamodelManagedType(TypeInformation<?> type) {
 
 		/**
 		 * Returns whether the given type is managed by one of the underlying {@link Metamodel} instances.
-		 * 
+		 *
 		 * @param type must not be {@literal null}.
 		 * @return
 		 */

src/main/java/org/springframework/data/jpa/repository/config/JpaMetamodelMappingContextFactoryBean.java

@@ -31,6 +31,7 @@
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationContextAware;
 import org.springframework.data.jpa.mapping.JpaMetamodelMappingContext;
+import org.springframework.data.jpa.util.JpaMetamodel;
 import org.springframework.data.util.StreamUtils;
 import org.springframework.lang.Nullable;
 
@@ -66,6 +67,11 @@ public Class<?> getObjectType() {
 		return JpaMetamodelMappingContext.class;
 	}
 
+	@Override
+	protected void destroyInstance(JpaMetamodelMappingContext instance) throws Exception {
+		JpaMetamodel.clearCache();
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.beans.factory.config.AbstractFactoryBean#createInstance()

src/main/java/org/springframework/data/jpa/util/JpaMetamodel.java

@@ -16,9 +16,9 @@
 package org.springframework.data.jpa.util;
 
 import java.util.Collection;
-import java.util.HashMap;
 import java.util.Map;
 import java.util.Optional;
+import java.util.concurrent.ConcurrentHashMap;
 
 import javax.persistence.metamodel.EntityType;
 import javax.persistence.metamodel.ManagedType;
@@ -34,10 +34,11 @@
  *
  * @author Oliver Gierke
  * @author Mark Paluch
+ * @author Sylvère Richard
  */
 public class JpaMetamodel {
 
-	private static final Map<Metamodel, JpaMetamodel> CACHE = new HashMap<>(4);
+	private static final Map<Metamodel, JpaMetamodel> CACHE = new ConcurrentHashMap<>(4);
 
 	private final Metamodel metamodel;
 
@@ -63,6 +64,10 @@ public static JpaMetamodel of(Metamodel metamodel) {
 		return CACHE.computeIfAbsent(metamodel, JpaMetamodel::new);
 	}
 
+	public static void clearCache() {
+		CACHE.clear();
+	}
+
 	/**
 	 * Returns whether the given type is managed by the backing JPA {@link Metamodel}.
 	 *
@@ -78,7 +83,7 @@ public boolean isJpaManaged(Class<?> type) {
 
 	/**
 	 * Returns whether the attribute of given name and type is the single identifier attribute of the given entity.
-	 * 
+	 *
 	 * @param entity must not be {@literal null}.
 	 * @param name must not be {@literal null}.
 	 * @param attributeType must not be {@literal null}.
@@ -98,7 +103,7 @@ public boolean isSingleIdAttribute(Class<?> entity, String name, Class<?> attrib
 	/**
 	 * Returns the {@link SingularAttribute} representing the identifier of the given {@link EntityType} if it contains a
 	 * singular one.
-	 * 
+	 *
 	 * @param entityType must not be {@literal null}.
 	 * @return
 	 */

src/test/java/org/springframework/data/jpa/util/JpaMetamodelUnitTests.java

@@ -30,8 +30,9 @@
 
 /**
  * Unit tests for {@link JpaMetamodel}.
- * 
+ *
  * @author Oliver Gierke
+ * @author Sylvère Richard
  */
 @RunWith(MockitoJUnitRunner.class)
 public class JpaMetamodelUnitTests {
@@ -47,4 +48,13 @@ public void skipsEntityTypesWithoutJavaTypeForIdentifierLookup() {
 
 		assertThat(JpaMetamodel.of(metamodel).isSingleIdAttribute(Object.class, "id", Object.class)).isFalse();
 	}
+
+	@Test //DATAJPA-1446
+	public void cacheIsEffectiveUnlessCleared() {
+		JpaMetamodel model1 = JpaMetamodel.of(metamodel);
+		assertThat(model1).isEqualTo(JpaMetamodel.of(metamodel));
+
+		JpaMetamodel.clearCache();
+		assertThat(model1).isNotEqualTo(JpaMetamodel.of(metamodel));
+	}
 }