DATAJDBC-130 - Support entities with List valued properties.

src/main/java/org/springframework/data/jdbc/core/DefaultDataAccessStrategy.java

@@ -200,11 +200,11 @@ public class DefaultDataAccessStrategy implements DataAccessStrategy {
 
 		Class<?> actualType = property.getActualType();
 		String findAllByProperty = sql(actualType).getFindAllByProperty(property.getReverseColumnName(),
-				property.getKeyColumn());
+				property.getKeyColumn(), property.isOrdered());
 
 		MapSqlParameterSource parameter = new MapSqlParameterSource(property.getReverseColumnName(), rootId);
 
-		return (Iterable<T>) operations.query(findAllByProperty, parameter, property.isQualified() //
+		return (Iterable<T>) operations.query(findAllByProperty, parameter, property.isMap() //
 				? getMapEntityRowMapper(property) //
 				: getEntityRowMapper(actualType));
 	}

src/main/java/org/springframework/data/jdbc/core/EntityRowMapper.java

@@ -19,10 +19,8 @@ import lombok.NonNull;
 
 import java.sql.ResultSet;
 import java.sql.SQLException;
-import java.util.Map;
-import java.util.Set;
-
 import org.springframework.core.convert.ConversionService;
+import org.springframework.core.convert.converter.Converter;
 import org.springframework.data.convert.ClassGeneratingEntityInstantiator;
 import org.springframework.data.convert.EntityInstantiator;
 import org.springframework.data.jdbc.mapping.model.JdbcMappingContext;
@@ -45,6 +43,8 @@ import org.springframework.jdbc.core.RowMapper;
  */
 public class EntityRowMapper<T> implements RowMapper<T> {
 
+	private static final Converter ITERABLE_OF_ENTRY_TO_MAP_CONVERTER = new IterableOfEntryToMapConverter();
+
 	private final JdbcPersistentEntity<T> entity;
 	private final EntityInstantiator instantiator = new ClassGeneratingEntityInstantiator();
 	private final ConversionService conversions;
@@ -79,13 +79,12 @@ public class EntityRowMapper<T> implements RowMapper<T> {
 
 		for (JdbcPersistentProperty property : entity) {
 
-			if (Set.class.isAssignableFrom(property.getType())) {
+			if (property.isCollectionLike()) {
 				propertyAccessor.setProperty(property, accessStrategy.findAllByProperty(id, property));
-			} else if (Map.class.isAssignableFrom(property.getType())) {
+			} else if (property.isMap()) {
 
 				Iterable<Object> allByProperty = accessStrategy.findAllByProperty(id, property);
-				IterableOfEntryToMapConverter converter = new IterableOfEntryToMapConverter();
-				propertyAccessor.setProperty(property, converter.convert(allByProperty));
+				propertyAccessor.setProperty(property, ITERABLE_OF_ENTRY_TO_MAP_CONVERTER.convert(allByProperty));
 			} else {
 				propertyAccessor.setProperty(property, readFrom(resultSet, property, ""));
 			}

src/main/java/org/springframework/data/jdbc/core/SqlGenerator.java

@@ -95,17 +95,22 @@ class SqlGenerator {
 	 * a referencing entity.
 	 *
 	 * @param columnName name of the column of the FK back to the referencing entity.
-	 * @param keyColumn if the property is of type {@link Map} this column contains the map key.
+	 * @param keyColumn  if the property is of type {@link Map} this column contains the map key.
+	 * @param ordered    whether the SQL statement should include an ORDER BY for the keyColumn. If this is {@literal true}, the keyColumn must not be {@literal null}.
 	 * @return a SQL String.
 	 */
-	String getFindAllByProperty(String columnName, String keyColumn) {
+	String getFindAllByProperty(String columnName, String keyColumn, boolean ordered) {
+
+		Assert.isTrue(keyColumn != null || !ordered, "If the SQL statement should be ordered a keyColumn to order by must be provided.");
 
 		String baseSelect = (keyColumn != null) //
 				? createSelectBuilder().column(cb -> cb.tableAlias(entity.getTableName()).column(keyColumn).as(keyColumn))
-						.build()
+				.build()
 				: getFindAll();
 
-		return String.format("%s WHERE %s = :%s", baseSelect, columnName, columnName);
+		String orderBy = ordered ? " ORDER BY " + keyColumn : "";
+
+		return String.format("%s WHERE %s = :%s%s", baseSelect, columnName, columnName, orderBy);
 	}
 
 	String getExists() {

src/main/java/org/springframework/data/jdbc/core/conversion/JdbcEntityWriter.java

@@ -16,12 +16,6 @@
 package org.springframework.data.jdbc.core.conversion;
 
 import lombok.RequiredArgsConstructor;
-
-import java.util.Collection;
-import java.util.Map;
-import java.util.Map.Entry;
-import java.util.stream.Stream;
-
 import org.springframework.data.jdbc.core.conversion.DbAction.Insert;
 import org.springframework.data.jdbc.core.conversion.DbAction.Update;
 import org.springframework.data.jdbc.mapping.model.JdbcMappingContext;
@@ -33,6 +27,13 @@ import org.springframework.data.mapping.PersistentPropertyAccessor;
 import org.springframework.data.util.StreamUtils;
 import org.springframework.util.ClassUtils;
 
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.stream.Stream;
+
 /**
  * Converts an entity that is about to be saved into {@link DbAction}s inside a {@link AggregateChange} that need to be
  * executed against the database to recreate the appropriate state in the database.
@@ -157,6 +158,10 @@ public class JdbcEntityWriter extends JdbcEntityWriterSupport {
 
 		Class<?> type = p.getType();
 
+		if (List.class.isAssignableFrom(type)) {
+			return listPropertyAsStream(p, propertyAccessor);
+		}
+
 		if (Collection.class.isAssignableFrom(type)) {
 			return collectionPropertyAsStream(p, propertyAccessor);
 		}
@@ -178,6 +183,21 @@ public class JdbcEntityWriter extends JdbcEntityWriterSupport {
 				: ((Collection<Object>) property).stream();
 	}
 
+	private Stream<Object> listPropertyAsStream(JdbcPersistentProperty p, PersistentPropertyAccessor propertyAccessor) {
+
+		Object property = propertyAccessor.getProperty(p);
+
+		if (property == null) return Stream.empty();
+
+		List<Object> listProperty = (List<Object>) property;
+		HashMap<Integer, Object> map = new HashMap<>();
+		for (int i = 0; i < listProperty.size(); i++) {
+			map.put(i, listProperty.get(i));
+		}
+
+		return map.entrySet().stream().map(e -> (Object) e);
+	}
+
 	private Stream<Object> mapPropertyAsStream(JdbcPersistentProperty p, PersistentPropertyAccessor propertyAccessor) {
 
 		Object property = propertyAccessor.getProperty(p);

src/main/java/org/springframework/data/jdbc/mapping/model/BasicJdbcPersistentProperty.java

@@ -15,12 +15,6 @@
  */
 package org.springframework.data.jdbc.mapping.model;
 
-import java.time.ZonedDateTime;
-import java.time.temporal.Temporal;
-import java.util.Date;
-import java.util.LinkedHashMap;
-import java.util.Map;
-
 import org.springframework.data.mapping.Association;
 import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.mapping.model.AnnotationBasedPersistentProperty;
@@ -29,6 +23,13 @@ import org.springframework.data.mapping.model.SimpleTypeHolder;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 
+import java.time.ZonedDateTime;
+import java.time.temporal.Temporal;
+import java.util.Date;
+import java.util.LinkedHashMap;
+import java.util.Map;
+import java.util.Set;
+
 /**
  * Meta data about a property to be used by repository implementations.
  *
@@ -114,7 +115,16 @@ public class BasicJdbcPersistentProperty extends AnnotationBasedPersistentProper
 
 	@Override
 	public boolean isQualified() {
-		return isMap();
+		return isMap() || isListLike();
+	}
+
+	private boolean isListLike() {
+		return isCollectionLike() && !Set.class.isAssignableFrom(this.getType());
+	}
+
+	@Override
+	public boolean isOrdered() {
+		return isListLike();
 	}
 
 	private Class columnTypeIfEntity(Class type) {

src/main/java/org/springframework/data/jdbc/mapping/model/JdbcPersistentProperty.java

@@ -51,4 +51,9 @@ public interface JdbcPersistentProperty extends PersistentProperty<JdbcPersisten
 	 * Returns if this property is a qualified property, i.e. a property referencing multiple elements that can get picked by a key or an index.
 	 */
 	boolean isQualified();
+
+	/**
+	 * Returns whether this property is an ordered property.
+	 */
+	boolean isOrdered();
 }