DATAJDBC-395 - Added dedicated configuration class for MyBatis integration.

We now ship MyBatisJdbcConfiguration as an alternative to (Abstract)JdbcConfiguration to tweak the DataAccessStrategy bean registered to create one that tries MyBatis mappings first but still delegates to the default one.

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

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.jdbc.repository.config;
+
+import org.apache.ibatis.session.SqlSession;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.data.jdbc.core.convert.DataAccessStrategy;
+import org.springframework.data.jdbc.core.convert.JdbcConverter;
+import org.springframework.data.jdbc.mybatis.MyBatisDataAccessStrategy;
+import org.springframework.data.relational.core.mapping.RelationalMappingContext;
+import org.springframework.jdbc.core.namedparam.NamedParameterJdbcOperations;
+
+/**
+ * Configuration class tweaking Spring Data JDBC to use a {@link MyBatisDataAccessStrategy} instead of the default one.
+ *
+ * @author Oliver Drotbohm
+ * @since 1.1
+ */
+@Configuration(proxyBeanMethods = false)
+public class MyBatisJdbcConfiguration extends AbstractJdbcConfiguration {
+
+	private @Autowired SqlSession session;
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.data.jdbc.repository.config.AbstractJdbcConfiguration#dataAccessStrategyBean(org.springframework.jdbc.core.namedparam.NamedParameterJdbcOperations, org.springframework.data.jdbc.core.convert.JdbcConverter, org.springframework.data.relational.core.mapping.RelationalMappingContext)
+	 */
+	@Bean
+	@Override
+	public DataAccessStrategy dataAccessStrategyBean(NamedParameterJdbcOperations operations, JdbcConverter jdbcConverter,
+			RelationalMappingContext context) {
+
+		return MyBatisDataAccessStrategy.createCombinedAccessStrategy(context, jdbcConverter, operations, session);
+	}
+}

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

@@ -0,0 +1,64 @@
+/*
+ * Copyright 2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.springframework.data.jdbc.repository.config;
+
+import static org.assertj.core.api.Assertions.*;
+import static org.mockito.Mockito.*;
+
+import java.util.List;
+
+import org.apache.ibatis.session.SqlSession;
+import org.junit.Test;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.data.jdbc.core.convert.CascadingDataAccessStrategy;
+import org.springframework.data.jdbc.core.convert.DataAccessStrategy;
+import org.springframework.data.jdbc.mybatis.MyBatisDataAccessStrategy;
+import org.springframework.test.util.ReflectionTestUtils;
+
+/**
+ * Integration tests for {@link MyBatisJdbcConfiguration}.
+ *
+ * @author Oliver Drotbohm
+ */
+public class MyBatisJdbcConfigurationIntegrationTests extends AbstractJdbcConfigurationIntegrationTests {
+
+	@Test // DATAJDBC-395
+	public void bootstrapsMyBatisDataAccessStrategy() {
+
+		assertApplicationContext(context -> {
+
+			assertThat(context.getBean(DataAccessStrategy.class)) //
+					.isInstanceOfSatisfying(CascadingDataAccessStrategy.class, it -> {
+
+						List<?> strategies = (List<?>) ReflectionTestUtils.getField(it, "strategies");
+
+						assertThat(strategies).hasSize(2);
+						assertThat(strategies.get(0)).isInstanceOf(MyBatisDataAccessStrategy.class);
+					});
+
+		}, MyBatisJdbcConfiguration.class, MyBatisInfrastructure.class);
+	}
+
+	@Configuration
+	static class MyBatisInfrastructure extends Infrastructure {
+
+		@Bean
+		public SqlSession session() {
+			return mock(SqlSession.class);
+		}
+	}
+}

src/main/asciidoc/jdbc.adoc

@@ -453,6 +453,33 @@ You can specify the following return types:
 [[jdbc.mybatis]]
 == MyBatis Integration
 
+The execution of CRUD operations and query methods can be delegated to MyBatis.
+This section describes how to configure Spring Data JDBC to integrate with MyBatis and which conventions to follow to hand over the execution of the queries as well as the mapping to the library.
+
+[[jdbc.mybatis.configuration]]
+== Configuration
+
+The easiest way to properly plug MyBatis into Spring Data JDBC is by importing `MyBatisJdbcConfiguration` into you application configuration:
+
+[source, java]
+----
+@Configuration
+@EnableJdbcRepositories
+@Import(MyBatisJdbcConfiguration.class)
+class Application {
+
+  @Bean
+  SqlSessionFactoryBean sqlSessionFactoryBean() {
+    // Configure MyBatis here
+  }
+}
+----
+
+As you can see, all you need to declare is a `SqlSessionFactoryBean` as `MyBatisJdbcConfiguration` relies on a `SqlSession` bean to be available in the `ApplicationContext` eventually.
+
+[[jdbc.mybatis.conventions]]
+== Usage conventions
+
 For each operation in `CrudRepository`, Spring Data JDBC runs multiple statements.
 If there is a https://github.com/mybatis/mybatis-3/blob/master/src/main/java/org/apache/ibatis/session/SqlSessionFactory.java[`SqlSessionFactory`] in the application context, Spring Data checks, for each step, whether the `SessionFactory` offers a statement.
 If one is found, that statement (including its configured mapping to an entity) is used.