Polishing.

Removes superfluous method.
Applied feedback from review: Formatting, Naming, and improved backward compatibility.

Originial pull request #981
See #935

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/core/dialect/JdbcDb2Dialect.java

@@ -17,9 +17,9 @@ package org.springframework.data.jdbc.core.dialect;
 
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.List;
 
 import org.springframework.data.relational.core.dialect.Db2Dialect;
-import org.springframework.data.relational.core.sql.IdentifierProcessing;
 
 /**
  * {@link Db2Dialect} that registers JDBC specific converters.
@@ -34,8 +34,8 @@ public class JdbcDb2Dialect extends Db2Dialect {
 	@Override
 	public Collection<Object> getConverters() {
 
-		ArrayList<Object> converters = new ArrayList<>(super.getConverters());
-		converters.add(OffsetDateTime2TimestampConverter.INSTANCE);
+		List<Object> converters = new ArrayList<>(super.getConverters());
+		converters.add(OffsetDateTimeToTimestampConverter.INSTANCE);
 
 		return converters;
 	}

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/core/dialect/JdbcH2Dialect.java

@@ -38,11 +38,11 @@ public class JdbcH2Dialect extends H2Dialect {
 
 	@Override
 	public Collection<Object> getConverters() {
-		return Collections.singletonList(TimestampWithTimeZone2OffsetDateTimeConverter.INSTANCE);
+		return Collections.singletonList(TimestampWithTimeZoneToOffsetDateTimeConverter.INSTANCE);
 	}
 
 	@ReadingConverter
-	enum TimestampWithTimeZone2OffsetDateTimeConverter implements Converter<TimestampWithTimeZone, OffsetDateTime> {
+	enum TimestampWithTimeZoneToOffsetDateTimeConverter implements Converter<TimestampWithTimeZone, OffsetDateTime> {
 		INSTANCE;
 
 

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

@@ -43,13 +43,13 @@ public class JdbcMySqlDialect extends MySqlDialect {
 	public Collection<Object> getConverters() {
 
 		ArrayList<Object> converters = new ArrayList<>(super.getConverters());
-		converters.add(OffsetDateTime2TimestampJdbcValueConverter.INSTANCE);
+		converters.add(OffsetDateTimeToTimestampJdbcValueConverter.INSTANCE);
 
 		return converters;
 	}
 
 	@WritingConverter
-	enum OffsetDateTime2TimestampJdbcValueConverter implements Converter<OffsetDateTime, JdbcValue> {
+	enum OffsetDateTimeToTimestampJdbcValueConverter implements Converter<OffsetDateTime, JdbcValue> {
 		INSTANCE;
 
 		@Override

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

@@ -23,11 +23,10 @@ import java.util.Collections;
 
 import org.springframework.core.convert.converter.Converter;
 import org.springframework.data.convert.ReadingConverter;
-import org.springframework.data.relational.core.dialect.Db2Dialect;
 import org.springframework.data.relational.core.dialect.SqlServerDialect;
 
 /**
- * {@link Db2Dialect} that registers JDBC specific converters.
+ * {@link SqlServerDialect} that registers JDBC specific converters.
  *
  * @author Jens Schauder
  * @since 2.3
@@ -38,11 +37,11 @@ public class JdbcSqlServerDialect extends SqlServerDialect {
 
 	@Override
 	public Collection<Object> getConverters() {
-		return Collections.singletonList(DateTimeOffset2OffsetDateTimeConverter.INSTANCE);
+		return Collections.singletonList(DateTimeOffsetToOffsetDateTimeConverter.INSTANCE);
 	}
 
 	@ReadingConverter
-	enum DateTimeOffset2OffsetDateTimeConverter implements Converter<DateTimeOffset, OffsetDateTime> {
+	enum DateTimeOffsetToOffsetDateTimeConverter implements Converter<DateTimeOffset, OffsetDateTime> {
 		INSTANCE;
 
 		@Override

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

@@ -31,7 +31,7 @@ import java.time.ZoneOffset;
  * @since 2.3
  */
 @WritingConverter
-enum OffsetDateTime2TimestampConverter implements Converter<OffsetDateTime, Timestamp> {
+enum OffsetDateTimeToTimestampConverter implements Converter<OffsetDateTime, Timestamp> {
 
 	INSTANCE;
 	@Override

spring-data-jdbc/src/main/java/org/springframework/data/jdbc/repository/config/AbstractJdbcConfiguration.java

@@ -20,7 +20,12 @@ import java.util.Collections;
 import java.util.List;
 import java.util.Optional;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.BeansException;
+import org.springframework.beans.factory.NoSuchBeanDefinitionException;
 import org.springframework.context.ApplicationContext;
+import org.springframework.context.ApplicationContextAware;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Lazy;
@@ -55,13 +60,17 @@ import org.springframework.jdbc.core.namedparam.NamedParameterJdbcOperations;
  * @since 1.1
  */
 @Configuration(proxyBeanMethods = false)
-public class AbstractJdbcConfiguration {
+public class AbstractJdbcConfiguration implements ApplicationContextAware {
+
+	private static Logger LOG = LoggerFactory.getLogger(AbstractJdbcConfiguration.class);
+
+	private ApplicationContext applicationContext;
 
 	/**
 	 * Register a {@link JdbcMappingContext} and apply an optional {@link NamingStrategy}.
 	 *
 	 * @param namingStrategy optional {@link NamingStrategy}. Use {@link NamingStrategy#INSTANCE} as fallback.
-	 * @param customConversions see {@link #jdbcCustomConversions(Dialect)}.
+	 * @param customConversions see {@link #jdbcCustomConversions()}.
 	 * @return must not be {@literal null}.
 	 */
 	@Bean
@@ -76,10 +85,11 @@ public class AbstractJdbcConfiguration {
 
 	/**
 	 * Creates a {@link RelationalConverter} using the configured
-	 * {@link #jdbcMappingContext(Optional, JdbcCustomConversions)}. Will get {@link #jdbcCustomConversions(Dialect)} ()} applied.
+	 * {@link #jdbcMappingContext(Optional, JdbcCustomConversions)}. Will get {@link #jdbcCustomConversions()} ()}
+	 * applied.
 	 *
 	 * @see #jdbcMappingContext(Optional, JdbcCustomConversions)
-	 * @see #jdbcCustomConversions(Dialect) ()
+	 * @see #jdbcCustomConversions()
 	 * @return must not be {@literal null}.
 	 */
 	@Bean
@@ -89,7 +99,7 @@ public class AbstractJdbcConfiguration {
 		DefaultJdbcTypeFactory jdbcTypeFactory = new DefaultJdbcTypeFactory(operations.getJdbcOperations());
 
 		return new BasicJdbcConverter(mappingContext, relationResolver, conversions, jdbcTypeFactory,
-			dialect.getIdentifierProcessing());
+				dialect.getIdentifierProcessing());
 	}
 
 	/**
@@ -101,10 +111,20 @@ public class AbstractJdbcConfiguration {
 	 * @return will never be {@literal null}.
 	 */
 	@Bean
-	public JdbcCustomConversions jdbcCustomConversions(Dialect dialect) {
+	public JdbcCustomConversions jdbcCustomConversions() {
+
+		try {
+
+			Dialect dialect = applicationContext.getBean(Dialect.class);
 
-		return new JdbcCustomConversions(CustomConversions.StoreConversions.of(JdbcSimpleTypes.HOLDER,
-				storeConverters(dialect)), userConverters());
+			return new JdbcCustomConversions(
+					CustomConversions.StoreConversions.of(JdbcSimpleTypes.HOLDER, storeConverters(dialect)), userConverters());
+		} catch (NoSuchBeanDefinitionException exception) {
+
+			LOG.warn("No dialect found. CustomConversions will be configured without dialect specific conversions.");
+
+			return new JdbcCustomConversions();
+		}
 	}
 
 	private List<?> userConverters() {
@@ -162,4 +182,9 @@ public class AbstractJdbcConfiguration {
 	public Dialect jdbcDialect(NamedParameterJdbcOperations operations) {
 		return DialectResolver.getDialect(operations.getJdbcOperations());
 	}
+
+	@Override
+	public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
+		this.applicationContext = applicationContext;
+	}
 }

spring-data-jdbc/src/test/java/org/springframework/data/jdbc/core/dialect/JdbcH2DialectTests.java

@@ -1,13 +1,3 @@
-package org.springframework.data.jdbc.core.dialect;
-
-import static org.assertj.core.api.Assertions.*;
-
-import java.time.OffsetDateTime;
-
-import org.h2.api.TimestampWithTimeZone;
-import org.h2.util.DateTimeUtils;
-import org.junit.jupiter.api.Test;
-
 /*
  * Copyright 2021 the original author or authors.
  *
@@ -23,6 +13,15 @@ import org.junit.jupiter.api.Test;
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+package org.springframework.data.jdbc.core.dialect;
+
+import static org.assertj.core.api.Assertions.*;
+
+import java.time.OffsetDateTime;
+
+import org.h2.api.TimestampWithTimeZone;
+import org.h2.util.DateTimeUtils;
+import org.junit.jupiter.api.Test;
 
 /**
  * Tests for {@link JdbcH2Dialect}.
@@ -34,7 +33,7 @@ class JdbcH2DialectTests {
 	@Test
 	void TimestampWithTimeZone2OffsetDateTimeConverterConvertsProperly() {
 
-		JdbcH2Dialect.TimestampWithTimeZone2OffsetDateTimeConverter converter = JdbcH2Dialect.TimestampWithTimeZone2OffsetDateTimeConverter.INSTANCE;
+		JdbcH2Dialect.TimestampWithTimeZoneToOffsetDateTimeConverter converter = JdbcH2Dialect.TimestampWithTimeZoneToOffsetDateTimeConverter.INSTANCE;
 		long dateValue = 123456789;
 		long timeNanos = 987654321;
 		int timeZoneOffsetSeconds = 4 * 60 * 60;

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

@@ -7,7 +7,6 @@ import java.time.OffsetDateTime;
 import java.time.ZoneOffset;
 
 import static org.assertj.core.api.Assertions.*;
-import static org.junit.jupiter.api.Assertions.*;
 
 /*
  * Copyright 2021 the original author or authors.
@@ -26,18 +25,18 @@ import static org.junit.jupiter.api.Assertions.*;
  */
 
 /**
- * Tests for {@link OffsetDateTime2TimestampConverter}.
+ * Tests for {@link OffsetDateTimeToTimestampConverter}.
  *
  * @author Jens Schauder
  */
-class OffsetDateTime2TimestampConverterUnitTests {
+class OffsetDateTimeToTimestampConverterUnitTests {
 
 	@Test
 	void conversionPreservesInstant() {
 
 		OffsetDateTime offsetDateTime = OffsetDateTime.of(5, 5, 5, 5,5,5,123456789, ZoneOffset.ofHours(3));
 
-		Timestamp timestamp = OffsetDateTime2TimestampConverter.INSTANCE.convert(offsetDateTime);
+		Timestamp timestamp = OffsetDateTimeToTimestampConverter.INSTANCE.convert(offsetDateTime);
 
 		assertThat(timestamp.toInstant()).isEqualTo(offsetDateTime.toInstant());
 	}

spring-data-jdbc/src/test/java/org/springframework/data/jdbc/repository/config/AbstractJdbcConfigurationIntegrationTests.java

@@ -110,7 +110,7 @@ public class AbstractJdbcConfigurationIntegrationTests {
 		}
 
 		@Override
-		public JdbcCustomConversions jdbcCustomConversions(Dialect dialect) {
+		public JdbcCustomConversions jdbcCustomConversions() {
 			return new JdbcCustomConversions(Collections.singletonList(Blah2BlubbConverter.INSTANCE));
 		}
 

spring-data-jdbc/src/test/java/org/springframework/data/jdbc/support/JdbcUtilTests.java

@@ -1,12 +1,3 @@
-package org.springframework.data.jdbc.support;
-
-import static org.assertj.core.api.Assertions.*;
-
-import java.sql.Types;
-import java.time.OffsetDateTime;
-
-import org.junit.jupiter.api.Test;
-
 /*
  * Copyright 2021 the original author or authors.
  *
@@ -22,6 +13,14 @@ import org.junit.jupiter.api.Test;
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+package org.springframework.data.jdbc.support;
+
+import static org.assertj.core.api.Assertions.*;
+
+import java.sql.Types;
+import java.time.OffsetDateTime;
+
+import org.junit.jupiter.api.Test;
 
 /**
  * Tests for {@link JdbcUtil}.

spring-data-jdbc/src/test/java/org/springframework/data/jdbc/testing/MySqlDataSourceConfiguration.java

@@ -77,4 +77,15 @@ class MySqlDataSourceConfiguration extends DataSourceConfiguration implements In
 					new ByteArrayResource("DROP DATABASE test;CREATE DATABASE test;".getBytes()));
 		}
 	}
+
+	private DataSource createRootDataSource() {
+
+		MysqlDataSource dataSource = new MysqlDataSource();
+		dataSource.setUrl(MYSQL_CONTAINER.getJdbcUrl());
+		dataSource.setUser("root");
+		dataSource.setPassword(MYSQL_CONTAINER.getPassword());
+		dataSource.setDatabaseName(MYSQL_CONTAINER.getDatabaseName());
+
+		return dataSource;
+	}
 }

spring-data-relational/src/main/java/org/springframework/data/relational/core/dialect/Db2Dialect.java

@@ -116,6 +116,6 @@ public class Db2Dialect extends AbstractDialect {
 
 	@Override
 	public Collection<Object> getConverters() {
-		return Collections.singletonList(Timestamp2OffsetDateTimeConverter.INSTANCE);
+		return Collections.singletonList(TimestampAtUtcToOffsetDateTimeConverter.INSTANCE);
 	}
 }

spring-data-relational/src/main/java/org/springframework/data/relational/core/dialect/MariaDbDialect.java

@@ -34,6 +34,6 @@ public class MariaDbDialect extends MySqlDialect {
 
 	@Override
 	public Collection<Object> getConverters() {
-		return Collections.singletonList(Timestamp2OffsetDateTimeConverter.INSTANCE);
+		return Collections.singletonList(TimestampAtUtcToOffsetDateTimeConverter.INSTANCE);
 	}
 }

spring-data-relational/src/main/java/org/springframework/data/relational/core/dialect/MySqlDialect.java

@@ -167,6 +167,6 @@ public class MySqlDialect extends AbstractDialect {
 
 	@Override
 	public Collection<Object> getConverters() {
-		return Collections.singletonList(Timestamp2OffsetDateTimeConverter.INSTANCE);
+		return Collections.singletonList(TimestampAtUtcToOffsetDateTimeConverter.INSTANCE);
 	}
 }

spring-data-relational/src/main/java/org/springframework/data/relational/core/dialect/OracleDialect.java

@@ -47,7 +47,7 @@ public class OracleDialect extends AnsiDialect {
 
 	@Override
 	public Collection<Object> getConverters() {
-		return Collections.singletonList(Timestamp2OffsetDateTimeConverter.INSTANCE);
+		return Collections.singletonList(TimestampAtUtcToOffsetDateTimeConverter.INSTANCE);
 	}
 
 }

spring-data-relational/src/main/java/org/springframework/data/relational/core/dialect/PostgresDialect.java

@@ -117,7 +117,7 @@ public class PostgresDialect extends AbstractDialect {
 
 	@Override
 	public Collection<Object> getConverters() {
-		return Collections.singletonList(Timestamp2OffsetDateTimeConverter.INSTANCE);
+		return Collections.singletonList(TimestampAtUtcToOffsetDateTimeConverter.INSTANCE);
 	}
 
 	static class PostgresLockClause implements LockClause {

spring-data-relational/src/main/java/org/springframework/data/relational/core/dialect/TimestampAtUtcToOffsetDateTimeConverter.java

@@ -31,7 +31,7 @@ import org.springframework.data.convert.ReadingConverter;
  * @since 2.3
  */
 @ReadingConverter
-enum Timestamp2OffsetDateTimeConverter implements Converter<Timestamp, OffsetDateTime> {
+enum TimestampAtUtcToOffsetDateTimeConverter implements Converter<Timestamp, OffsetDateTime> {
 
 	INSTANCE;
 

spring-data-relational/src/test/java/org/springframework/data/relational/core/dialect/TimestampAtUtcToOffsetDateTimeConverterUnitTests.java

@@ -1,13 +1,12 @@
 package org.springframework.data.relational.core.dialect;
 
-import org.junit.jupiter.api.Test;
+import static org.assertj.core.api.Assertions.*;
 
 import java.sql.Timestamp;
 import java.time.Instant;
 import java.time.OffsetDateTime;
 
-import static org.assertj.core.api.Assertions.*;
-import static org.junit.jupiter.api.Assertions.*;
+import org.junit.jupiter.api.Test;
 
 /*
  * Copyright 2021 the original author or authors.
@@ -26,18 +25,18 @@ import static org.junit.jupiter.api.Assertions.*;
  */
 
 /**
- * Tests {@link Timestamp2OffsetDateTimeConverter}.
+ * Tests {@link TimestampAtUtcToOffsetDateTimeConverter}.
  *
  * @author Jens Schauder
  */
-class Timestamp2OffsetDateTimeConverterUnitTests {
+class TimestampAtUtcToOffsetDateTimeConverterUnitTests {
 
 	@Test
 	void conversionMaintainsInstant() {
 
 		Timestamp timestamp = Timestamp.from(Instant.now());
-		OffsetDateTime converted = Timestamp2OffsetDateTimeConverter.INSTANCE.convert(timestamp);
+		OffsetDateTime converted = TimestampAtUtcToOffsetDateTimeConverter.INSTANCE.convert(timestamp);
 
 		assertThat(converted.toInstant()).isEqualTo(timestamp.toInstant());
 	}
-}
+}