Add support for factory methods.

R2DBC now supports the use of factory methods for entity creation.
Spring Data JDBC already does so via f326897

Simply annotate a static factory method on your entity class with `@PersistenceCreator`.

Closes #1346
See spring-projects/spring-data-commons#2476
See f326897

Author: schauder

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

@@ -37,7 +37,6 @@
 import org.springframework.data.mapping.Parameter;
 import org.springframework.data.mapping.PersistentPropertyAccessor;
 import org.springframework.data.mapping.PersistentPropertyPath;
-import org.springframework.data.mapping.PreferredConstructor;
 import org.springframework.data.mapping.context.MappingContext;
 import org.springframework.data.mapping.model.DefaultSpELExpressionEvaluator;
 import org.springframework.data.mapping.model.ParameterValueProvider;
@@ -52,7 +51,6 @@
 import org.springframework.data.relational.core.mapping.RelationalPersistentProperty;
 import org.springframework.data.relational.core.sql.IdentifierProcessing;
 import org.springframework.data.util.TypeInformation;
-import org.springframework.data.util.TypeInformation;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 

spring-data-r2dbc/src/main/java/org/springframework/data/r2dbc/convert/MappingR2dbcConverter.java

@@ -32,10 +32,10 @@
 import org.springframework.dao.InvalidDataAccessApiUsageException;
 import org.springframework.data.convert.CustomConversions;
 import org.springframework.data.mapping.IdentifierAccessor;
+import org.springframework.data.mapping.InstanceCreatorMetadata;
 import org.springframework.data.mapping.MappingException;
 import org.springframework.data.mapping.PersistentProperty;
 import org.springframework.data.mapping.PersistentPropertyAccessor;
-import org.springframework.data.mapping.PreferredConstructor;
 import org.springframework.data.mapping.context.MappingContext;
 import org.springframework.data.mapping.model.ConvertingPropertyAccessor;
 import org.springframework.data.mapping.model.DefaultSpELExpressionEvaluator;
@@ -311,7 +311,7 @@ private <S> S readEntityFrom(Row row, @Nullable RowMetadata metadata, Persistent
 	private <S> S createInstance(Row row, @Nullable RowMetadata rowMetadata, String prefix,
 			RelationalPersistentEntity<S> entity) {
 
-		PreferredConstructor<S, RelationalPersistentProperty> persistenceConstructor = entity.getPersistenceConstructor();
+		InstanceCreatorMetadata<RelationalPersistentProperty> persistenceConstructor = entity.getInstanceCreatorMetadata();
 		ParameterValueProvider<RelationalPersistentProperty> provider;
 
 		if (persistenceConstructor != null && persistenceConstructor.hasParameters()) {
@@ -716,10 +716,6 @@ public RowParameterValueProvider(Row resultSet, RowMetadata metadata, Relational
 			this.prefix = prefix;
 		}
 
-		/*
-		 * (non-Javadoc)
-		 * @see org.springframework.data.mapping.model.ParameterValueProvider#getParameterValue(org.springframework.data.mapping.PreferredConstructor.Parameter)
-		 */
 		@Override
 		@Nullable
 		public <T> T getParameterValue(