DATAJDBC-181 - Use NamingStrategy for instantiating entities.

The ResultSetParameterValueProvider uses the relevant property for a requested parameter in order to obtain the proper column name to use.

Improved mocking of ResultSets in tests to actually fail when a non existing column gets requested instead of just returning null.

Author: schauder

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

@@ -16,6 +16,7 @@
 package org.springframework.data.jdbc.core;
 
 import lombok.NonNull;
+import lombok.RequiredArgsConstructor;
 import org.springframework.core.convert.ConversionService;
 import org.springframework.core.convert.converter.Converter;
 import org.springframework.data.convert.ClassGeneratingEntityInstantiator;
@@ -94,7 +95,7 @@ public T mapRow(ResultSet resultSet, int rowNumber) throws SQLException {
 	}
 
 	private T createInstance(ResultSet rs) {
-		return instantiator.createInstance(entity, ResultSetParameterValueProvider.of(rs, conversions, ""));
+		return instantiator.createInstance(entity, new ResultSetParameterValueProvider(rs, entity, conversions, ""));
 	}
 
 	private Object readFrom(ResultSet resultSet, JdbcPersistentProperty property, String prefix) {
@@ -123,7 +124,7 @@ private <S> S readEntityFrom(ResultSet rs, PersistentProperty<?> property) {
 			return null;
 		}
 
-		S instance = instantiator.createInstance(entity, ResultSetParameterValueProvider.of(rs, conversions, prefix));
+		S instance = instantiator.createInstance(entity, new ResultSetParameterValueProvider(rs, entity, conversions, prefix));
 
 		PersistentPropertyAccessor accessor = entity.getPropertyAccessor(instance);
 		ConvertingPropertyAccessor propertyAccessor = new ConvertingPropertyAccessor(accessor, conversions);
@@ -135,40 +136,27 @@ private <S> S readEntityFrom(ResultSet rs, PersistentProperty<?> property) {
 		return instance;
 	}
 
+	@RequiredArgsConstructor
 	private static class ResultSetParameterValueProvider implements ParameterValueProvider<JdbcPersistentProperty> {
 
 		@NonNull
 		private final ResultSet resultSet;
 		@NonNull
+		private final JdbcPersistentEntity<?> entity;
+		@NonNull
 		private final ConversionService conversionService;
 		@NonNull
 		private final String prefix;
 
-		private ResultSetParameterValueProvider(ResultSet resultSet, ConversionService conversionService, String prefix) {
-
-			this.resultSet = resultSet;
-			this.conversionService = conversionService;
-			this.prefix = prefix;
-		}
-
-		public static ResultSetParameterValueProvider of(ResultSet resultSet, ConversionService conversionService,
-														 String prefix) {
-			return new ResultSetParameterValueProvider(resultSet, conversionService, prefix);
-		}
-
 		/*
 		 * (non-Javadoc)
 		 * @see org.springframework.data.mapping.model.ParameterValueProvider#getParameterValue(org.springframework.data.mapping.PreferredConstructor.Parameter)
 		 */
 		@Override
 		public <T> T getParameterValue(Parameter<T, JdbcPersistentProperty> parameter) {
 
-			String name = parameter.getName();
-			if (name == null) {
-				return null;
-			}
+			String column = prefix + entity.getRequiredPersistentProperty(parameter.getName()).getColumnName();
 
-			String column = prefix + name;
 			try {
 				return conversionService.convert(resultSet.getObject(column), parameter.getType().getType());
 			} catch (SQLException o_O) {

src/test/java/org/springframework/data/jdbc/core/EntityRowMapperUnitTests.java

@@ -23,9 +23,12 @@
 import org.springframework.core.convert.support.GenericConversionService;
 import org.springframework.data.annotation.Id;
 import org.springframework.data.convert.Jsr310Converters;
+import org.springframework.data.jdbc.mapping.model.DefaultNamingStrategy;
 import org.springframework.data.jdbc.mapping.model.JdbcMappingContext;
 import org.springframework.data.jdbc.mapping.model.JdbcPersistentEntity;
 import org.springframework.data.jdbc.mapping.model.JdbcPersistentProperty;
+import org.springframework.data.jdbc.mapping.model.NamingStrategy;
+import org.springframework.data.repository.query.Param;
 import org.springframework.jdbc.core.namedparam.NamedParameterJdbcOperations;
 import org.springframework.util.Assert;
 
@@ -54,6 +57,12 @@ public class EntityRowMapperUnitTests {
 	public static final long ID_FOR_ENTITY_REFERENCING_MAP = 42L;
 	public static final long ID_FOR_ENTITY_REFERENCING_LIST = 4711L;
 	public static final long ID_FOR_ENTITY_NOT_REFERENCING_MAP = 23L;
+	public static final DefaultNamingStrategy X_APPENDING_NAMINGSTRATEGY = new DefaultNamingStrategy() {
+		@Override
+		public String getColumnName(JdbcPersistentProperty property) {
+			return super.getColumnName(property) + "x";
+		}
+	};
 
 	@Test // DATAJDBC-113
 	public void simpleEntitiesGetProperlyExtracted() throws SQLException {
@@ -70,6 +79,36 @@ public void simpleEntitiesGetProperlyExtracted() throws SQLException {
 				.containsExactly(ID_FOR_ENTITY_NOT_REFERENCING_MAP, "alpha");
 	}
 
+	@Test // DATAJDBC-181
+	public void namingStrategyGetsHonored() throws SQLException {
+
+		ResultSet rs = mockResultSet(asList("idx", "namex"), //
+				ID_FOR_ENTITY_NOT_REFERENCING_MAP, "alpha");
+		rs.next();
+
+		Trivial extracted = createRowMapper(Trivial.class, X_APPENDING_NAMINGSTRATEGY).mapRow(rs, 1);
+
+		assertThat(extracted) //
+				.isNotNull() //
+				.extracting(e -> e.id, e -> e.name) //
+				.containsExactly(ID_FOR_ENTITY_NOT_REFERENCING_MAP, "alpha");
+	}
+
+	@Test // DATAJDBC-181
+	public void namingStrategyGetsHonoredForConstructor() throws SQLException {
+
+		ResultSet rs = mockResultSet(asList("idx", "namex"), //
+				ID_FOR_ENTITY_NOT_REFERENCING_MAP, "alpha");
+		rs.next();
+
+		TrivialImmutable extracted = createRowMapper(TrivialImmutable.class, X_APPENDING_NAMINGSTRATEGY).mapRow(rs, 1);
+
+		assertThat(extracted) //
+				.isNotNull() //
+				.extracting(e -> e.id, e -> e.name) //
+				.containsExactly(ID_FOR_ENTITY_NOT_REFERENCING_MAP, "alpha");
+	}
+
 	@Test // DATAJDBC-113
 	public void simpleOneToOneGetsProperlyExtracted() throws SQLException {
 
@@ -131,8 +170,18 @@ public void listReferenceGetsLoadedWithAdditionalSelect() throws SQLException {
 	}
 
 	private <T> EntityRowMapper<T> createRowMapper(Class<T> type) {
+		return createRowMapper(type, new DefaultNamingStrategy());
+	}
+
+	private <T> EntityRowMapper<T> createRowMapper(Class<T> type, NamingStrategy namingStrategy) {
+
+		JdbcMappingContext context = new JdbcMappingContext( //
+				namingStrategy, //
+				mock(NamedParameterJdbcOperations.class), //
+				__ -> {
+				} //
+		);
 
-		JdbcMappingContext context = new JdbcMappingContext(mock(NamedParameterJdbcOperations.class));
 		DataAccessStrategy accessStrategy = mock(DataAccessStrategy.class);
 
 		// the ID of the entity is used to determine what kind of ResultSet is needed for subsequent selects.
@@ -240,7 +289,12 @@ private boolean isBeforeFirst() {
 		}
 
 		private Object getObject(String column) {
-			return values.get(index).get(column);
+
+			Map<String, Object> rowMap = values.get(index);
+
+			Assert.isTrue(rowMap.containsKey(column), String.format("Trying to access a column (%s) that does not exist", column));
+
+			return rowMap.get(column);
 		}
 
 		private boolean next() {
@@ -251,6 +305,13 @@ private boolean next() {
 	}
 
 	@RequiredArgsConstructor
+	static class TrivialImmutable {
+
+		@Id
+		private final Long id;
+		private final String name;
+	}
+
 	static class Trivial {
 
 		@Id