DATAJDBC-370 - Fixed handling of entities with no withers.

pom.xml

@@ -5,7 +5,7 @@
 
 	<groupId>org.springframework.data</groupId>
 	<artifactId>spring-data-relational-parent</artifactId>
-	<version>1.1.0.BUILD-SNAPSHOT</version>
+	<version>1.1.0.DATAJDBC-370-SNAPSHOT</version>
 	<packaging>pom</packaging>
 
 	<name>Spring Data Relational Parent</name>

spring-data-jdbc-distribution/pom.xml

@@ -14,7 +14,7 @@
 	<parent>
 		<groupId>org.springframework.data</groupId>
 		<artifactId>spring-data-relational-parent</artifactId>
-		<version>1.1.0.BUILD-SNAPSHOT</version>
+		<version>1.1.0.DATAJDBC-370-SNAPSHOT</version>
 		<relativePath>../pom.xml</relativePath>
 	</parent>
 

spring-data-jdbc/pom.xml

@@ -5,7 +5,7 @@
 	<modelVersion>4.0.0</modelVersion>
 
 	<artifactId>spring-data-jdbc</artifactId>
-	<version>1.1.0.BUILD-SNAPSHOT</version>
+	<version>1.1.0.DATAJDBC-370-SNAPSHOT</version>
 
 	<name>Spring Data JDBC</name>
 	<description>Spring Data module for JDBC repositories.</description>
@@ -14,7 +14,7 @@
 	<parent>
 		<groupId>org.springframework.data</groupId>
 		<artifactId>spring-data-relational-parent</artifactId>
-		<version>1.1.0.BUILD-SNAPSHOT</version>
+		<version>1.1.0.DATAJDBC-370-SNAPSHOT</version>
 	</parent>
 
 	<properties>

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

@@ -30,7 +30,6 @@
 import org.springframework.data.jdbc.core.mapping.AggregateReference;
 import org.springframework.data.jdbc.support.JdbcUtil;
 import org.springframework.data.mapping.MappingException;
-import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.mapping.PersistentPropertyAccessor;
 import org.springframework.data.mapping.PreferredConstructor;
 import org.springframework.data.mapping.context.MappingContext;
@@ -53,6 +52,7 @@
  *
  * @author Mark Paluch
  * @author Jens Schauder
+ * @author Christoph Strobl
  * @see MappingContext
  * @see SimpleTypeHolder
  * @see CustomConversions
@@ -285,30 +285,22 @@ public ReadingContext(RelationalPersistentEntity<T> entity, DataAccessStrategy a
 		}
 
 		private ReadingContext<?> extendBy(RelationalPersistentProperty property) {
-			return new ReadingContext<>(entity, accessStrategy, resultSet, path.extendBy(property));
+			return new ReadingContext(getMappingContext().getRequiredPersistentEntity(property.getActualType()),
+					accessStrategy, resultSet, path.extendBy(property));
 		}
 
 		T mapRow() {
 
 			RelationalPersistentProperty idProperty = entity.getIdProperty();
 
-			Object idValue = null;
-			if (idProperty != null) {
-				idValue = readFrom(idProperty);
-			}
+			Object idValue = idProperty == null ? null : readFrom(idProperty);
 
-			T result = createInstanceInternal(entity, idValue);
-
-			return entity.requiresPropertyPopulation() //
-					? populateProperties(result) //
-					: result;
+			return createInstanceInternal(idValue);
 		}
 
-		private T populateProperties(T result) {
-
-			PersistentPropertyAccessor<T> propertyAccessor = getPropertyAccessor(entity, result);
+		private T populateProperties(T instance, @Nullable Object idValue) {
 
-			Object id = idProperty == null ? null : readFrom(idProperty);
+			PersistentPropertyAccessor<T> propertyAccessor = getPropertyAccessor(entity, instance);
 
 			PreferredConstructor<T, RelationalPersistentProperty> persistenceConstructor = entity.getPersistenceConstructor();
 
@@ -318,7 +310,7 @@ private T populateProperties(T result) {
 					continue;
 				}
 
-				propertyAccessor.setProperty(property, readOrLoadProperty(id, property));
+				propertyAccessor.setProperty(property, readOrLoadProperty(idValue, property));
 			}
 
 			return propertyAccessor.getBean();
@@ -354,31 +346,38 @@ private Object readFrom(RelationalPersistentProperty property) {
 
 			Object value = getObjectFromResultSet(path.extendBy(property).getColumnAlias());
 			return readValue(value, property.getTypeInformation());
-
 		}
 
-		@SuppressWarnings("unchecked")
-		private Object readEmbeddedEntityFrom(@Nullable Object id, RelationalPersistentProperty property) {
+		@Nullable
+		private Object readEmbeddedEntityFrom(@Nullable Object idValue, RelationalPersistentProperty property) {
 
-			ReadingContext newContext = extendBy(property);
+			ReadingContext<?> newContext = extendBy(property);
+			return newContext.hasInstanceValues(idValue) ? newContext.createInstanceInternal(idValue) : null;
+		}
 
-			RelationalPersistentEntity<?> entity = getMappingContext().getRequiredPersistentEntity(property.getActualType());
+		private boolean hasInstanceValues(Object idValue) {
 
-			Object instance = newContext.createInstanceInternal(entity, null);
+			RelationalPersistentEntity<?> persistentEntity = path.getLeafEntity();
 
-			PersistentPropertyAccessor<?> accessor = getPropertyAccessor((PersistentEntity<Object, ?>) entity, instance);
+			for (RelationalPersistentProperty embeddedProperty : persistentEntity) {
 
-			for (RelationalPersistentProperty p : entity) {
-				accessor.setProperty(p, newContext.readOrLoadProperty(id, p));
+				// if the embedded contains Lists, Sets or Maps we consider it non-empty
+				if (embeddedProperty.isQualified() || embeddedProperty.isReference()) {
+					return true;
+				}
+
+				if (readOrLoadProperty(idValue, embeddedProperty) != null) {
+					return true;
+				}
 			}
 
-			return instance;
+			return false;
 		}
 
 		@Nullable
 		private <S> S readEntityFrom(RelationalPersistentProperty property, PersistentPropertyPathExtension path) {
 
-			ReadingContext<?> newContext = extendBy(property);
+			ReadingContext<S> newContext = (ReadingContext<S>) extendBy(property);
 
 			RelationalPersistentEntity<S> entity = (RelationalPersistentEntity<S>) getMappingContext()
 					.getRequiredPersistentEntity(property.getActualType());
@@ -398,15 +397,7 @@ private <S> S readEntityFrom(RelationalPersistentProperty property, PersistentPr
 				return null;
 			}
 
-			S instance = newContext.createInstanceInternal(entity, idValue);
-
-			PersistentPropertyAccessor<S> accessor = getPropertyAccessor(entity, instance);
-
-			for (RelationalPersistentProperty p : entity) {
-				accessor.setProperty(p, newContext.readOrLoadProperty(idValue, p));
-			}
-
-			return instance;
+			return newContext.createInstanceInternal(idValue);
 		}
 
 		@Nullable
@@ -419,9 +410,9 @@ private Object getObjectFromResultSet(String backreferenceName) {
 			}
 		}
 
-		private <S> S createInstanceInternal(RelationalPersistentEntity<S> entity, @Nullable Object idValue) {
+		private T createInstanceInternal(@Nullable Object idValue) {
 
-			return createInstance(entity, parameter -> {
+			T instance = createInstance(entity, parameter -> {
 
 				String parameterName = parameter.getName();
 
@@ -431,6 +422,7 @@ private <S> S createInstanceInternal(RelationalPersistentEntity<S> entity, @Null
 
 				return readOrLoadProperty(idValue, property);
 			});
+			return populateProperties(instance, idValue);
 		}
 
 	}

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

@@ -54,6 +54,7 @@
  * @author Mark Paluch
  * @author Thomas Lang
  * @author Bastian Wilhelm
+ * @author Christoph Strobl
  * @since 1.1
  */
 public class DefaultDataAccessStrategy implements DataAccessStrategy {
@@ -313,7 +314,8 @@ private <S, T> MapSqlParameterSource getParameterSource(S instance, RelationalPe
 
 		MapSqlParameterSource parameters = new MapSqlParameterSource();
 
-		PersistentPropertyAccessor<S> propertyAccessor = persistentEntity.getPropertyAccessor(instance);
+		PersistentPropertyAccessor<S> propertyAccessor = instance != null ? persistentEntity.getPropertyAccessor(instance)
+				: NoValuePropertyAccessor.instance();
 
 		persistentEntity.doWithProperties((PropertyHandler<RelationalPersistentProperty>) property -> {
 
@@ -480,4 +482,33 @@ static Predicate<RelationalPersistentProperty> includeAll() {
 			return it -> false;
 		}
 	}
+
+	/**
+	 * A {@link PersistentPropertyAccessor} implementation always returning null
+	 * 
+	 * @param <T>
+	 */
+	static class NoValuePropertyAccessor<T> implements PersistentPropertyAccessor<T> {
+
+		private static final NoValuePropertyAccessor INSTANCE = new NoValuePropertyAccessor();
+
+		static <T> NoValuePropertyAccessor<T> instance() {
+			return INSTANCE;
+		}
+
+		@Override
+		public void setProperty(PersistentProperty<?> property, Object value) {
+			throw new UnsupportedOperationException("Cannot set value on 'null' target object.");
+		}
+
+		@Override
+		public Object getProperty(PersistentProperty<?> property) {
+			return null;
+		}
+
+		@Override
+		public T getBean() {
+			return null;
+		}
+	}
 }

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

@@ -436,7 +436,7 @@ public void saveAndLoadAnEntityWithByteArray() {
 		assertThat(reloaded.binaryData).isEqualTo(new byte[] { 1, 23, 42 });
 	}
 
-	@Test
+	@Test // DATAJDBC-340
 	public void saveAndLoadLongChain() {
 
 		Chain4 chain4 = new Chain4();