Properly convert Map keys.

Keys of maps now get properly converted.
Among others this enables the use of enums as keys.

Closes #1656
Original pull request: #1663

Author: schauder

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

@@ -241,7 +241,7 @@ private Object getIdFrom(DbAction.WithEntity<?> idOwningAction) {
 		RelationalPersistentEntity<?> persistentEntity = getRequiredPersistentEntity(idOwningAction.getEntityType());
 		Object identifier = persistentEntity.getIdentifierAccessor(idOwningAction.getEntity()).getIdentifier();
 
-		Assert.state(identifier != null, "Couldn't obtain a required id value");
+		Assert.state(identifier != null,() -> "Couldn't obtain a required id value for " + persistentEntity);
 
 		return identifier;
 	}

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

@@ -23,6 +23,7 @@
 import org.springframework.data.relational.core.mapping.AggregatePath;
 import org.springframework.data.relational.core.sql.SqlIdentifier;
 import org.springframework.data.relational.domain.RowDocument;
+import org.springframework.data.util.TypeInformation;
 import org.springframework.jdbc.core.RowMapper;
 
 /**
@@ -51,15 +52,19 @@ class MapEntityRowMapper<T> implements RowMapper<Map.Entry<Object, T>> {
 	@Override
 	public Map.Entry<Object, T> mapRow(ResultSet rs, int rowNum) throws SQLException {
 
-		Object key = rs.getObject(keyColumn.getReference());
-		return new HashMap.SimpleEntry<>(key, mapEntity(rs, key));
+		RowDocument document = RowDocumentResultSetExtractor.toRowDocument(rs);
+
+		Object key = document.get(keyColumn.getReference());
+		Class<?> qualifierColumnType = path.getRequiredLeafProperty().getQualifierColumnType();
+		Object convertedKey = converter.readValue(key, TypeInformation.of(qualifierColumnType));
+
+		return new HashMap.SimpleEntry<>(convertedKey, mapEntity(document, key));
 	}
 
 	@SuppressWarnings("unchecked")
-	private T mapEntity(ResultSet resultSet, Object key) throws SQLException {
+	private T mapEntity(RowDocument document, Object key) {
 
-		RowDocument document = RowDocumentResultSetExtractor.toRowDocument(resultSet);
-		return (T) converter.readAndResolve(path.getLeafEntity().getType(), document,
+		return (T) converter.readAndResolve(path.getRequiredLeafEntity().getType(), document,
 				identifier.withPart(keyColumn, key, Object.class));
 	}
 }

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

@@ -1278,6 +1278,16 @@ void recordOfSet() {
 		assertThat(authors).containsExactly(tolkien);
 	}
 
+	@Test // GH-1656
+	void mapWithEnumKey() {
+
+		EnumMapOwner enumMapOwner = template.save(new EnumMapOwner(null, "OwnerName", Map.of(Color.BLUE, new MapElement("Element"))));
+
+		Iterable<EnumMapOwner> enumMapOwners = template.findAll(EnumMapOwner.class);
+
+		assertThat(enumMapOwners).containsExactly(enumMapOwner);
+	}
+
 	private <T extends Number> void saveAndUpdateAggregateWithVersion(VersionedAggregate aggregate,
 			Function<Number, T> toConcreteNumber) {
 		saveAndUpdateAggregateWithVersion(aggregate, toConcreteNumber, 0);
@@ -2096,6 +2106,10 @@ record Book(String name) {
 
 	}
 
+	record EnumMapOwner(@Id Long id, String name, Map<Color, MapElement> map) {
+	}
+
+
 	@Configuration
 	@Import(TestConfiguration.class)
 	static class Config {

spring-data-jdbc/src/test/resources/org.springframework.data.jdbc.core/JdbcAggregateTemplateIntegrationTests-db2.sql

@@ -50,6 +50,8 @@ DROP TABLE SET_ELEMENT;
 DROP TABLE BOOK;
 DROP TABLE AUTHOR;
 
+DROP TABLE ENUM_MAP_OWNER;
+
 CREATE TABLE LEGO_SET
 (
   "id1"  BIGINT GENERATED BY DEFAULT AS IDENTITY (START WITH 1) PRIMARY KEY,
@@ -406,6 +408,8 @@ CREATE TABLE MAP_ELEMENT
 (
     MULTIPLE_COLLECTIONS BIGINT,
     MULTIPLE_COLLECTIONS_KEY VARCHAR(10),
+    ENUM_MAP_OWNER BIGINT,
+    ENUM_MAP_OWNER_KEY VARCHAR(10),
     NAME VARCHAR(100)
 );
 
@@ -419,3 +423,9 @@ CREATE TABLE BOOK
     AUTHOR BIGINT,
     NAME VARCHAR(100)
 );
+
+CREATE TABLE ENUM_MAP_OWNER
+(
+    ID BIGINT GENERATED BY DEFAULT AS IDENTITY (START WITH 1) PRIMARY KEY,
+    NAME VARCHAR(100)
+);

spring-data-jdbc/src/test/resources/org.springframework.data.jdbc.core/JdbcAggregateTemplateIntegrationTests-h2.sql

@@ -365,6 +365,8 @@ CREATE TABLE MAP_ELEMENT
 (
     MULTIPLE_COLLECTIONS BIGINT,
     MULTIPLE_COLLECTIONS_KEY VARCHAR(10),
+    ENUM_MAP_OWNER BIGINT,
+    ENUM_MAP_OWNER_KEY VARCHAR(10),
     NAME VARCHAR(100)
 );
 
@@ -378,3 +380,9 @@ CREATE TABLE BOOK
     AUTHOR BIGINT,
     NAME VARCHAR(100)
 );
+
+CREATE TABLE ENUM_MAP_OWNER
+(
+    ID SERIAL PRIMARY KEY,
+    NAME VARCHAR(100)
+);

spring-data-jdbc/src/test/resources/org.springframework.data.jdbc.core/JdbcAggregateTemplateIntegrationTests-hsql.sql

@@ -366,6 +366,8 @@ CREATE TABLE MAP_ELEMENT
 (
     MULTIPLE_COLLECTIONS BIGINT,
     MULTIPLE_COLLECTIONS_KEY VARCHAR(10),
+    ENUM_MAP_OWNER BIGINT,
+    ENUM_MAP_OWNER_KEY VARCHAR(10),
     NAME VARCHAR(100)
 );
 
@@ -379,3 +381,9 @@ CREATE TABLE BOOK
     AUTHOR BIGINT,
     NAME VARCHAR(100)
 );
+
+CREATE TABLE ENUM_MAP_OWNER
+(
+    ID BIGINT GENERATED BY DEFAULT AS IDENTITY (START WITH 1) PRIMARY KEY,
+    NAME VARCHAR(100)
+);

spring-data-jdbc/src/test/resources/org.springframework.data.jdbc.core/JdbcAggregateTemplateIntegrationTests-mariadb.sql

@@ -339,6 +339,8 @@ CREATE TABLE MAP_ELEMENT
 (
     MULTIPLE_COLLECTIONS BIGINT,
     MULTIPLE_COLLECTIONS_KEY VARCHAR(10),
+    ENUM_MAP_OWNER BIGINT,
+    ENUM_MAP_OWNER_KEY VARCHAR(10),
     NAME VARCHAR(100)
 );
 
@@ -352,3 +354,9 @@ CREATE TABLE BOOK
     AUTHOR BIGINT,
     NAME VARCHAR(100)
 );
+
+CREATE TABLE ENUM_MAP_OWNER
+(
+    ID BIGINT AUTO_INCREMENT PRIMARY KEY,
+    NAME VARCHAR(100)
+);

spring-data-jdbc/src/test/resources/org.springframework.data.jdbc.core/JdbcAggregateTemplateIntegrationTests-mssql.sql

@@ -377,6 +377,8 @@ CREATE TABLE MAP_ELEMENT
 (
     MULTIPLE_COLLECTIONS BIGINT,
     MULTIPLE_COLLECTIONS_KEY VARCHAR(10),
+    ENUM_MAP_OWNER BIGINT,
+    ENUM_MAP_OWNER_KEY VARCHAR(10),
     NAME VARCHAR(100)
 );
 
@@ -393,3 +395,10 @@ CREATE TABLE BOOK
     AUTHOR BIGINT,
     NAME VARCHAR(100)
 );
+
+DROP TABLE ENUM_MAP_OWNER;
+CREATE TABLE ENUM_MAP_OWNER
+(
+    ID BIGINT IDENTITY PRIMARY KEY,
+    NAME VARCHAR(100)
+);

spring-data-jdbc/src/test/resources/org.springframework.data.jdbc.core/JdbcAggregateTemplateIntegrationTests-mysql.sql

@@ -344,6 +344,8 @@ CREATE TABLE MAP_ELEMENT
 (
   MULTIPLE_COLLECTIONS BIGINT,
   MULTIPLE_COLLECTIONS_KEY VARCHAR(10),
+  ENUM_MAP_OWNER BIGINT,
+  ENUM_MAP_OWNER_KEY VARCHAR(10),
   NAME VARCHAR(100)
 );
 
@@ -357,3 +359,9 @@ CREATE TABLE BOOK
     AUTHOR BIGINT,
     NAME VARCHAR(100)
 );
+
+CREATE TABLE ENUM_MAP_OWNER
+(
+    ID BIGINT AUTO_INCREMENT PRIMARY KEY,
+    NAME VARCHAR(100)
+);

spring-data-jdbc/src/test/resources/org.springframework.data.jdbc.core/JdbcAggregateTemplateIntegrationTests-oracle.sql

@@ -40,6 +40,8 @@ DROP TABLE SET_ELEMENT CASCADE CONSTRAINTS PURGE;
 DROP TABLE BOOK CASCADE CONSTRAINTS PURGE;
 DROP TABLE AUTHOR CASCADE CONSTRAINTS PURGE;
 
+DROP TABLE ENUM_MAP_OWNER CASCADE CONSTRAINTS PURGE;
+
 CREATE TABLE LEGO_SET
 (
     "id1" NUMBER GENERATED by default on null as IDENTITY PRIMARY KEY,
@@ -387,6 +389,8 @@ CREATE TABLE MAP_ELEMENT
 (
     MULTIPLE_COLLECTIONS NUMBER,
     MULTIPLE_COLLECTIONS_KEY VARCHAR(10),
+    ENUM_MAP_OWNER BIGINT,
+    ENUM_MAP_OWNER_KEY VARCHAR(10),
     NAME VARCHAR(100)
 );
 
@@ -400,3 +404,9 @@ CREATE TABLE BOOK
     AUTHOR NUMBER,
     NAME VARCHAR(100)
 );
+
+CREATE TABLE ENUM_MAP_OWNER
+(
+    ID BIGINT GENERATED BY DEFAULT AS IDENTITY PRIMARY KEY,
+    NAME VARCHAR(100)
+);