#95 - Use customized ConnectionFactory lookup to avoid AbstractR2dbcConfiguration proxying.

We now attempt to lookup ConnectionFactory from ApplicationContext and fall back to a local
method call if ConnectionFactory is not exposed as bean.

Original pull request: #96.

src/main/java/org/springframework/data/r2dbc/config/AbstractR2dbcConfiguration.java

@@ -20,6 +20,9 @@ import io.r2dbc.spi.ConnectionFactory;
 import java.util.Collections;
 import java.util.Optional;
 
+import org.springframework.beans.BeansException;
+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.core.convert.converter.Converter;
@@ -37,6 +40,7 @@ import org.springframework.data.r2dbc.support.SqlErrorCodeR2dbcExceptionTranslat
 import org.springframework.data.relational.core.conversion.BasicRelationalConverter;
 import org.springframework.data.relational.core.mapping.NamingStrategy;
 import org.springframework.data.relational.core.mapping.RelationalMappingContext;
+import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 
 /**
@@ -48,8 +52,21 @@ import org.springframework.util.Assert;
  * @see DatabaseClient
  * @see org.springframework.data.r2dbc.repository.config.EnableR2dbcRepositories
  */
-@Configuration
-public abstract class AbstractR2dbcConfiguration {
+@Configuration(proxyBeanMethods = false)
+public abstract class AbstractR2dbcConfiguration implements ApplicationContextAware {
+
+	private static final String CONNECTION_FACTORY_BEAN_NAME = "connectionFactory";
+
+	private @Nullable ApplicationContext context;
+
+	/*
+	 * (non-Javadoc)
+	 * @see org.springframework.context.ApplicationContextAware#setApplicationContext(org.springframework.context.ApplicationContext)
+	 */
+	@Override
+	public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
+		this.context = applicationContext;
+	}
 
 	/**
 	 * Return a R2DBC {@link ConnectionFactory}. Annotate with {@link Bean} in case you want to expose a
@@ -91,7 +108,7 @@ public abstract class AbstractR2dbcConfiguration {
 		Assert.notNull(exceptionTranslator, "ExceptionTranslator must not be null!");
 
 		return DatabaseClient.builder() //
-				.connectionFactory(connectionFactory()) //
+				.connectionFactory(lookupConnectionFactory()) //
 				.dataAccessStrategy(dataAccessStrategy) //
 				.exceptionTranslator(exceptionTranslator) //
 				.build();
@@ -137,7 +154,7 @@ public abstract class AbstractR2dbcConfiguration {
 
 		MappingR2dbcConverter converter = new MappingR2dbcConverter(mappingContext, r2dbcCustomConversions);
 
-		return new DefaultReactiveDataAccessStrategy(getDialect(connectionFactory()), converter);
+		return new DefaultReactiveDataAccessStrategy(getDialect(lookupConnectionFactory()), converter);
 	}
 
 	/**
@@ -160,7 +177,7 @@ public abstract class AbstractR2dbcConfiguration {
 	 */
 	protected StoreConversions getStoreConversions() {
 
-		Dialect dialect = getDialect(connectionFactory());
+		Dialect dialect = getDialect(lookupConnectionFactory());
 		return StoreConversions.of(dialect.getSimpleTypeHolder(), R2dbcCustomConversions.STORE_CONVERTERS);
 	}
 
@@ -172,6 +189,23 @@ public abstract class AbstractR2dbcConfiguration {
 	 */
 	@Bean
 	public R2dbcExceptionTranslator exceptionTranslator() {
-		return new SqlErrorCodeR2dbcExceptionTranslator(connectionFactory());
+		return new SqlErrorCodeR2dbcExceptionTranslator(lookupConnectionFactory());
+	}
+
+	ConnectionFactory lookupConnectionFactory() {
+
+		ApplicationContext context = this.context;
+		Assert.notNull(context, "ApplicationContext is not yet initialized");
+
+		String[] beanNamesForType = context.getBeanNamesForType(ConnectionFactory.class);
+
+		for (String beanName : beanNamesForType) {
+
+			if (beanName.equals(CONNECTION_FACTORY_BEAN_NAME)) {
+				return context.getBean(CONNECTION_FACTORY_BEAN_NAME, ConnectionFactory.class);
+			}
+		}
+
+		return connectionFactory();
 	}
 }

src/test/java/org/springframework/data/r2dbc/config/R2dbcConfigurationIntegrationTests.java

@@ -0,0 +1,147 @@
+/*
+ * 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.r2dbc.config;
+
+import static org.assertj.core.api.Assertions.*;
+import static org.mockito.Mockito.*;
+
+import io.r2dbc.h2.H2ConnectionConfiguration;
+import io.r2dbc.h2.H2ConnectionFactory;
+import io.r2dbc.spi.ConnectionFactory;
+
+import org.junit.Test;
+
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.data.r2dbc.function.DatabaseClient;
+
+/**
+ * Tests for {@link AbstractR2dbcConfiguration}.
+ *
+ * @author Mark Paluch
+ */
+public class R2dbcConfigurationIntegrationTests {
+
+	@Test // gh-95
+	public void shouldLookupConnectionFactoryThroughLocalCall() {
+
+		AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(
+				NonBeanConnectionFactoryConfiguration.class);
+
+		context.getBean(DatabaseClient.class);
+
+		NonBeanConnectionFactoryConfiguration bean = context.getBean(NonBeanConnectionFactoryConfiguration.class);
+
+		assertThat(context.getBeanNamesForType(ConnectionFactory.class)).isEmpty();
+		assertThat(bean.callCounter).isGreaterThan(2);
+
+		context.stop();
+	}
+
+	@Test // gh-95
+	public void shouldLookupConnectionFactoryThroughLocalCallForExistingCustomBeans() {
+
+		AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(
+				CustomConnectionFactoryBeanNameConfiguration.class);
+
+		context.getBean(DatabaseClient.class);
+
+		CustomConnectionFactoryBeanNameConfiguration bean = context
+				.getBean(CustomConnectionFactoryBeanNameConfiguration.class);
+
+		assertThat(context.getBeanNamesForType(ConnectionFactory.class)).hasSize(1).contains("myCustomBean");
+		assertThat(bean.callCounter).isGreaterThan(2);
+
+		ConnectionFactoryWrapper wrapper = context.getBean(ConnectionFactoryWrapper.class);
+		assertThat(wrapper.connectionFactory).isExactlyInstanceOf(H2ConnectionFactory.class);
+
+		context.stop();
+	}
+
+	@Test // gh-95
+	public void shouldRegisterConnectionFactory() {
+
+		AnnotationConfigApplicationContext context = new AnnotationConfigApplicationContext(
+				BeanConnectionFactoryConfiguration.class);
+
+		context.getBean(DatabaseClient.class);
+
+		BeanConnectionFactoryConfiguration bean = context.getBean(BeanConnectionFactoryConfiguration.class);
+
+		assertThat(bean.callCounter).isEqualTo(1);
+		assertThat(context.getBeanNamesForType(ConnectionFactory.class)).hasSize(1);
+
+		context.stop();
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	static class NonBeanConnectionFactoryConfiguration extends AbstractR2dbcConfiguration {
+
+		int callCounter;
+
+		@Override
+		public ConnectionFactory connectionFactory() {
+
+			callCounter++;
+			return new H2ConnectionFactory(
+					H2ConnectionConfiguration.builder().inMemory("foo").username("sa").password("").build());
+		}
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	static class CustomConnectionFactoryBeanNameConfiguration extends AbstractR2dbcConfiguration {
+
+		int callCounter;
+
+		@Bean
+		public ConnectionFactory myCustomBean() {
+			return mock(ConnectionFactory.class);
+		}
+
+		@Override
+		public ConnectionFactory connectionFactory() {
+
+			callCounter++;
+			return new H2ConnectionFactory(
+					H2ConnectionConfiguration.builder().inMemory("foo").username("sa").password("").build());
+		}
+
+		@Bean
+		ConnectionFactoryWrapper wrapper() {
+			return new ConnectionFactoryWrapper(lookupConnectionFactory());
+		}
+	}
+
+	static class ConnectionFactoryWrapper {
+		ConnectionFactory connectionFactory;
+
+		ConnectionFactoryWrapper(ConnectionFactory connectionFactory) {
+			this.connectionFactory = connectionFactory;
+		}
+	}
+
+	@Configuration(proxyBeanMethods = false)
+	static class BeanConnectionFactoryConfiguration extends NonBeanConnectionFactoryConfiguration {
+
+		@Override
+		@Bean
+		public ConnectionFactory connectionFactory() {
+			return super.connectionFactory();
+		}
+	}
+
+}