DATAJDBC-399 - Performance improvements in metadata lookups.

Avoid Stream usage in favor of a simple for loop in event triggering in JdbcAggregateTemplate. Tweaked JdbcMappingContext to verify the presence of parameter names on metadata creation. Avoid the re-resolution of the column name for a property by caching the resolved column name. This significantly improves performance as it avoids repeated parsing and concatenation of strings. Added caching to PersistentPropertyPathExtension.

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/core/JdbcAggregateTemplate.java

@@ -15,10 +15,10 @@
  */
 package org.springframework.data.jdbc.core;
 
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Optional;
 import java.util.function.Function;
-import java.util.stream.Collectors;
-import java.util.stream.StreamSupport;
 
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationEventPublisher;
@@ -364,13 +364,17 @@ public class JdbcAggregateTemplate implements JdbcAggregateOperations {
 
 	private <T> Iterable<T> triggerAfterLoad(Iterable<T> all) {
 
-		return StreamSupport.stream(all.spliterator(), false).map(e -> {
+		List<T> result = new ArrayList<>();
+
+		for (T e : all) {
 
 			RelationalPersistentEntity<?> entity = context.getRequiredPersistentEntity(e.getClass());
 			IdentifierAccessor identifierAccessor = entity.getIdentifierAccessor(e);
 
-			return triggerAfterLoad(identifierAccessor.getRequiredIdentifier(), e);
+			result.add(triggerAfterLoad(identifierAccessor.getRequiredIdentifier(), e));
-		}).collect(Collectors.toList());
+		}
+
+		return result;
 	}
 
 	private <T> T triggerAfterLoad(Object id, T entity) {

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/core/convert/SqlGeneratorSource.java

@@ -18,9 +18,9 @@ package org.springframework.data.jdbc.core.convert;
 import lombok.RequiredArgsConstructor;
 
 import java.util.Map;
-import java.util.concurrent.ConcurrentHashMap;
 
 import org.springframework.data.relational.core.mapping.RelationalMappingContext;
+import org.springframework.util.ConcurrentReferenceHashMap;
 
 /**
  * Provides {@link SqlGenerator}s per domain type. Instances get cached, so when asked multiple times for the same
@@ -31,12 +31,10 @@ import org.springframework.data.relational.core.mapping.RelationalMappingContext
 @RequiredArgsConstructor
 public class SqlGeneratorSource {
 
-	private final Map<Class, SqlGenerator> sqlGeneratorCache = new ConcurrentHashMap<>();
+	private final Map<Class<?>, SqlGenerator> CACHE = new ConcurrentReferenceHashMap<>();
 	private final RelationalMappingContext context;
 
 	SqlGenerator getSqlGenerator(Class<?> domainType) {
-
+		return CACHE.computeIfAbsent(domainType, t -> new SqlGenerator(context, context.getRequiredPersistentEntity(t)));
-		return sqlGeneratorCache.computeIfAbsent(domainType,
-				t -> new SqlGenerator(context, context.getRequiredPersistentEntity(t)));
 	}
 }

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/core/mapping/JdbcMappingContext.java

@@ -15,6 +15,8 @@
  */
 package org.springframework.data.jdbc.core.mapping;
 
+import org.springframework.data.mapping.PreferredConstructor;
+import org.springframework.data.mapping.PreferredConstructor.Parameter;
 import org.springframework.data.mapping.context.MappingContext;
 import org.springframework.data.mapping.model.Property;
 import org.springframework.data.mapping.model.SimpleTypeHolder;
@@ -23,6 +25,8 @@ import org.springframework.data.relational.core.mapping.RelationalMappingContext
 import org.springframework.data.relational.core.mapping.RelationalPersistentEntity;
 import org.springframework.data.relational.core.mapping.RelationalPersistentProperty;
 import org.springframework.data.util.TypeInformation;
+import org.springframework.util.Assert;
+import org.springframework.util.StringUtils;
 
 /**
  * {@link MappingContext} implementation for JDBC.
@@ -35,6 +39,8 @@ import org.springframework.data.util.TypeInformation;
  */
 public class JdbcMappingContext extends RelationalMappingContext {
 
+	private static final String MISSING_PARAMETER_NAME = "A constructor parameter name must not be null to be used with Spring Data JDBC! Offending parameter: %s";
+
 	/**
 	 * Creates a new {@link JdbcMappingContext}.
 	 */
@@ -51,6 +57,27 @@ public class JdbcMappingContext extends RelationalMappingContext {
 		super(namingStrategy);
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.relational.core.mapping.RelationalMappingContext#createPersistentEntity(org.springframework.data.util.TypeInformation)
+	 */
+	@Override
+	protected <T> RelationalPersistentEntity<T> createPersistentEntity(TypeInformation<T> typeInformation) {
+
+		RelationalPersistentEntity<T> entity = super.createPersistentEntity(typeInformation);
+		PreferredConstructor<T, RelationalPersistentProperty> constructor = entity.getPersistenceConstructor();
+
+		if (constructor == null) {
+			return entity;
+		}
+
+		for (Parameter<Object, RelationalPersistentProperty> parameter : constructor.getParameters()) {
+			Assert.state(StringUtils.hasText(parameter.getName()), () -> String.format(MISSING_PARAMETER_NAME, parameter));
+		}
+
+		return entity;
+	}
+
 	/*
 	 * (non-Javadoc)
 	 * @see org.springframework.data.mapping.context.AbstractMappingContext#createPersistentProperty(org.springframework.data.mapping.model.Property, org.springframework.data.mapping.model.MutablePersistentEntity, org.springframework.data.mapping.model.SimpleTypeHolder)

spring-data-jdbc/src/test/java/org/springframework/data/jdbc/core/convert/SqlGeneratorFixedNamingStrategyUnitTests.java

@@ -20,7 +20,6 @@ import static org.assertj.core.api.Assertions.*;
 import org.assertj.core.api.SoftAssertions;
 import org.junit.Test;
 import org.springframework.data.annotation.Id;
-import org.springframework.data.jdbc.core.convert.SqlGenerator;
 import org.springframework.data.jdbc.core.mapping.JdbcMappingContext;
 import org.springframework.data.jdbc.core.mapping.PersistentPropertyPathTestUtils;
 import org.springframework.data.mapping.PersistentPropertyPath;

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/BasicRelationalPersistentProperty.java

@@ -29,6 +29,7 @@ import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.mapping.model.AnnotationBasedPersistentProperty;
 import org.springframework.data.mapping.model.Property;
 import org.springframework.data.mapping.model.SimpleTypeHolder;
+import org.springframework.data.relational.core.mapping.Embedded.OnEmpty;
 import org.springframework.data.util.Lazy;
 import org.springframework.data.util.Optionals;
 import org.springframework.lang.Nullable;
@@ -57,9 +58,9 @@ public class BasicRelationalPersistentProperty extends AnnotationBasedPersistent
 	}
 
 	private final RelationalMappingContext context;
-	private final Lazy<Optional<String>> columnName;
+	private final Lazy<String> columnName;
 	private final Lazy<Optional<String>> collectionIdColumnName;
-	private final Lazy<Optional<String>> collectionKeyColumnName;
+	private final Lazy<String> collectionKeyColumnName;
 	private final Lazy<Boolean> isEmbedded;
 	private final Lazy<String> embeddedPrefix;
 	private final Lazy<Class<?>> columnType = Lazy.of(this::doGetColumnType);
@@ -89,7 +90,8 @@ public class BasicRelationalPersistentProperty extends AnnotationBasedPersistent
 
 		this.columnName = Lazy.of(() -> Optional.ofNullable(findAnnotation(Column.class)) //
 				.map(Column::value) //
-				.filter(StringUtils::hasText));
+				.filter(StringUtils::hasText) //
+				.orElseGet(() -> context.getNamingStrategy().getColumnName(this)));
 
 		this.collectionIdColumnName = Lazy.of(() -> Optionals
 				.toStream(Optional.ofNullable(findAnnotation(MappedCollection.class)).map(MappedCollection::idColumn),
@@ -99,7 +101,7 @@ public class BasicRelationalPersistentProperty extends AnnotationBasedPersistent
 		this.collectionKeyColumnName = Lazy.of(() -> Optionals
 				.toStream(Optional.ofNullable(findAnnotation(MappedCollection.class)).map(MappedCollection::keyColumn),
 						Optional.ofNullable(findAnnotation(Column.class)).map(Column::keyColumn)) //
-				.filter(StringUtils::hasText).findFirst());
+				.filter(StringUtils::hasText).findFirst().orElseGet(() -> context.getNamingStrategy().getKeyColumn(this)));
 	}
 
 	/*
@@ -127,7 +129,7 @@ public class BasicRelationalPersistentProperty extends AnnotationBasedPersistent
 	 */
 	@Override
 	public String getColumnName() {
-		return columnName.get().orElseGet(() -> context.getNamingStrategy().getColumnName(this));
+		return columnName.get();
 	}
 
 	/**
@@ -188,12 +190,7 @@ public class BasicRelationalPersistentProperty extends AnnotationBasedPersistent
 
 	@Override
 	public String getKeyColumn() {
-
+		return isQualified() ? collectionKeyColumnName.get() : null;
-		if (isQualified()) {
-			return collectionKeyColumnName.get().orElseGet(() -> context.getNamingStrategy().getKeyColumn(this));
-		} else {
-			return null;
-		}
 	}
 
 	@Override
@@ -229,6 +226,18 @@ public class BasicRelationalPersistentProperty extends AnnotationBasedPersistent
 		return isEmbedded() ? embeddedPrefix.get() : null;
 	}
 
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.relational.core.mapping.RelationalPersistentProperty#shouldCreateEmptyEmbedded()
+	 */
+	@Override
+	public boolean shouldCreateEmptyEmbedded() {
+
+		Embedded findAnnotation = findAnnotation(Embedded.class);
+
+		return findAnnotation != null && OnEmpty.USE_EMPTY.equals(findAnnotation.onEmpty());
+	}
+
 	private boolean isListLike() {
 		return isCollectionLike() && !Set.class.isAssignableFrom(this.getType());
 	}

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/CachingNamingStrategy.java

@@ -0,0 +1,117 @@
+/*
+ * Copyright 2019 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.relational.core.mapping;
+
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+import org.springframework.data.util.Lazy;
+import org.springframework.util.Assert;
+import org.springframework.util.ConcurrentReferenceHashMap;
+
+/**
+ * A {@link NamingStrategy} to cache the results of the target one.
+ *
+ * @author Oliver Drotbohm
+ * @since 1.1
+ */
+class CachingNamingStrategy implements NamingStrategy {
+
+	private final NamingStrategy delegate;
+
+	private final Map<RelationalPersistentProperty, String> columnNames = new ConcurrentHashMap<>();
+	private final Map<RelationalPersistentProperty, String> keyColumns = new ConcurrentHashMap<>();
+	private final Map<Class<?>, String> qualifiedTableNames = new ConcurrentReferenceHashMap<>();
+	private final Map<Class<?>, String> tableNames = new ConcurrentReferenceHashMap<>();
+
+	private final Lazy<String> schema;
+
+	/**
+	 * Creates a new {@link CachingNamingStrategy} with the given delegate {@link NamingStrategy}.
+	 *
+	 * @param delegate must not be {@literal null}.
+	 */
+	public CachingNamingStrategy(NamingStrategy delegate) {
+
+		Assert.notNull(delegate, "Delegate must not be null!");
+
+		this.delegate = delegate;
+		this.schema = Lazy.of(delegate::getSchema);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.relational.core.mapping.NamingStrategy#getKeyColumn(org.springframework.data.relational.core.mapping.RelationalPersistentProperty)
+	 */
+	@Override
+	public String getKeyColumn(RelationalPersistentProperty property) {
+		return keyColumns.computeIfAbsent(property, delegate::getKeyColumn);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.relational.core.mapping.NamingStrategy#getQualifiedTableName(java.lang.Class)
+	 */
+	@Override
+	public String getQualifiedTableName(Class<?> type) {
+		return qualifiedTableNames.computeIfAbsent(type, delegate::getQualifiedTableName);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.relational.core.mapping.NamingStrategy#getTableName(java.lang.Class)
+	 */
+	@Override
+	public String getTableName(Class<?> type) {
+		return tableNames.computeIfAbsent(type, delegate::getTableName);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.relational.core.mapping.NamingStrategy#getReverseColumnName(org.springframework.data.relational.core.mapping.PersistentPropertyPathExtension)
+	 */
+	@Override
+	public String getReverseColumnName(PersistentPropertyPathExtension path) {
+		return delegate.getReverseColumnName(path);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.relational.core.mapping.NamingStrategy#getReverseColumnName(org.springframework.data.relational.core.mapping.RelationalPersistentProperty)
+	 */
+	@Override
+	public String getReverseColumnName(RelationalPersistentProperty property) {
+		return delegate.getReverseColumnName(property);
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.relational.core.mapping.NamingStrategy#getSchema()
+	 */
+	@Override
+	public String getSchema() {
+		return schema.get();
+	}
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.relational.core.mapping.NamingStrategy#getColumnName(org.springframework.data.relational.core.mapping.RelationalPersistentProperty)
+	 */
+	@Override
+	public String getColumnName(RelationalPersistentProperty property) {
+		return columnNames.computeIfAbsent(property, delegate::getColumnName);
+	}
+}

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/PersistentPropertyPathExtension.java

@@ -20,6 +20,7 @@ import lombok.EqualsAndHashCode;
 import org.springframework.data.mapping.PersistentProperty;
 import org.springframework.data.mapping.PersistentPropertyPath;
 import org.springframework.data.mapping.context.MappingContext;
+import org.springframework.data.util.Lazy;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
@@ -30,13 +31,15 @@ import org.springframework.util.Assert;
  * @author Jens Schauder
  * @since 1.1
  */
-@EqualsAndHashCode
+@EqualsAndHashCode(exclude = { "columnAlias", "context" })
 public class PersistentPropertyPathExtension {
 
 	private final RelationalPersistentEntity<?> entity;
 	private final @Nullable PersistentPropertyPath<RelationalPersistentProperty> path;
 	private final MappingContext<RelationalPersistentEntity<?>, RelationalPersistentProperty> context;
 
+	private final Lazy<String> columnAlias = Lazy.of(() -> prefixWithTableAlias(getColumnName()));
+
 	/**
 	 * Creates the empty path referencing the root itself.
 	 *
@@ -188,8 +191,7 @@ public class PersistentPropertyPathExtension {
 	 * @throws IllegalStateException when called on an empty path.
 	 */
 	public String getColumnAlias() {
-
+		return columnAlias.get();
-		return prefixWithTableAlias(getColumnName());
 	}
 
 	/**
@@ -316,12 +318,9 @@ public class PersistentPropertyPathExtension {
 	 */
 	public PersistentPropertyPathExtension extendBy(RelationalPersistentProperty property) {
 
-		PersistentPropertyPath<RelationalPersistentProperty> newPath;
+		PersistentPropertyPath<RelationalPersistentProperty> newPath = path == null //
-		if (path == null) {
+				? context.getPersistentPropertyPath(property.getName(), entity.getType()) //
-			newPath = context.getPersistentPropertyPath(property.getName(), entity.getType());
+				: context.getPersistentPropertyPath(path.toDotPath() + "." + property.getName(), entity.getType());
-		} else {
-			newPath = context.getPersistentPropertyPath(path.toDotPath() + "." + property.getName(), entity.getType());
-		}
 
 		return new PersistentPropertyPathExtension(context, newPath);
 	}
@@ -409,12 +408,16 @@ public class PersistentPropertyPathExtension {
 		if (path.getLength() <= 1) {
 			return suffix;
 		}
+
 		PersistentPropertyPath<RelationalPersistentProperty> parentPath = path.getParentPath();
 		RelationalPersistentProperty parentLeaf = parentPath.getRequiredLeafProperty();
+
 		if (!parentLeaf.isEmbedded()) {
 			return suffix;
 		}
+
 		String embeddedPrefix = parentLeaf.getEmbeddedPrefix();
+
 		return getParentPath().assembleColumnName(embeddedPrefix + suffix);
 	}
 

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/RelationalMappingContext.java

@@ -54,7 +54,7 @@ public class RelationalMappingContext
 
 		Assert.notNull(namingStrategy, "NamingStrategy must not be null!");
 
-		this.namingStrategy = namingStrategy;
+		this.namingStrategy = new CachingNamingStrategy(namingStrategy);
 
 		setSimpleTypeHolder(SimpleTypeHolder.DEFAULT);
 	}

spring-data-relational/src/main/java/org/springframework/data/relational/core/mapping/RelationalPersistentProperty.java

@@ -97,4 +97,11 @@ public interface RelationalPersistentProperty extends PersistentProperty<Relatio
 	default String getEmbeddedPrefix() {
 		return null;
 	};
+
+	/**
+	 * Returns whether an empty embedded object is supposed to be created for this property.
+	 *
+	 * @return
+	 */
+	boolean shouldCreateEmptyEmbedded();
 }