Stop JPA and a custom Flyway bean from causing a startup failure

Previously, if an application used JPA and declared its own Flyway bean,
startup would fail. The custom Flyway bean would switch off
auto-configuration of the FlywayMigrationInitializer bean but the
context’s entity manager factory beans would still be configured to
depend on the migration initialiser.

This commit splits the post-processor that configures the dependencies
into two. One that configures the dependency on the Flyway bean and
one that configures the dependency on the FlywayMigrationInitializer
bean. When to auto-configuration of the FlywayMigrationInitializer is
switched off, the auto-configuration of the latter dependency is also
switched off.

Closes gh-4079

spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/flyway/FlywayAutoConfiguration.java

@@ -35,7 +35,6 @@ import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.boot.context.properties.EnableConfigurationProperties;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
-import org.springframework.context.annotation.Import;
 import org.springframework.core.io.DefaultResourceLoader;
 import org.springframework.core.io.ResourceLoader;
 import org.springframework.orm.jpa.AbstractEntityManagerFactoryBean;
@@ -60,7 +59,6 @@ public class FlywayAutoConfiguration {
 	@Configuration
 	@ConditionalOnMissingBean(Flyway.class)
 	@EnableConfigurationProperties(FlywayProperties.class)
-	@Import(FlywayJpaDependencyConfiguration.class)
 	public static class FlywayConfiguration {
 
 		@Autowired
@@ -122,6 +120,21 @@ public class FlywayAutoConfiguration {
 		@ConditionalOnMissingBean
 		public FlywayMigrationInitializer flywayInitializer(Flyway flyway) {
 			return new FlywayMigrationInitializer(flyway, this.migrationStrategy);
+		}
+
+		/**
+		 * Additional configuration to ensure that {@link EntityManagerFactory} beans
+		 * depend-on the {@code flywayInitializer} bean.
+		 */
+		@Configuration
+		@ConditionalOnClass(LocalContainerEntityManagerFactoryBean.class)
+		@ConditionalOnBean(AbstractEntityManagerFactoryBean.class)
+		protected class FlywayInitializerJpaDependencyConfiguration extends
+				EntityManagerFactoryDependsOnPostProcessor {
+
+			public FlywayInitializerJpaDependencyConfiguration() {
+				super("flywayInitializer");
+			}
 
 		}
 
@@ -129,7 +142,7 @@ public class FlywayAutoConfiguration {
 
 	/**
 	 * Additional configuration to ensure that {@link EntityManagerFactory} beans
-	 * depend-on the flyway bean.
+	 * depend-on the {@code flyway} bean.
 	 */
 	@Configuration
 	@ConditionalOnClass(LocalContainerEntityManagerFactoryBean.class)
@@ -138,7 +151,7 @@ public class FlywayAutoConfiguration {
 			EntityManagerFactoryDependsOnPostProcessor {
 
 		public FlywayJpaDependencyConfiguration() {
-			super("flywayInitializer", "flyway");
+			super("flyway");
 		}
 
 	}

spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/flyway/FlywayAutoConfigurationTests.java

@@ -17,6 +17,7 @@
 package org.springframework.boot.autoconfigure.flyway;
 
 import java.util.Arrays;
+import java.util.Collections;
 
 import javax.sql.DataSource;
 
@@ -27,14 +28,18 @@ import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.ExpectedException;
 import org.springframework.beans.factory.BeanCreationException;
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.PropertyPlaceholderAutoConfiguration;
 import org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder;
 import org.springframework.boot.autoconfigure.jdbc.EmbeddedDataSourceConfiguration;
+import org.springframework.boot.orm.jpa.EntityManagerFactoryBuilder;
 import org.springframework.boot.test.EnvironmentTestUtils;
 import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.Ordered;
+import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
+import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
 import org.springframework.stereotype.Component;
 
 import static org.hamcrest.Matchers.equalTo;
@@ -47,6 +52,7 @@ import static org.junit.Assert.assertThat;
  *
  * @author Dave Syer
  * @author Phillip Webb
+ * @author Andy Wilkinson
  */
 public class FlywayAutoConfigurationTests {
 
@@ -171,7 +177,13 @@ public class FlywayAutoConfigurationTests {
 		FlywayMigrationInitializer initializer = this.context
 				.getBean(FlywayMigrationInitializer.class);
 		assertThat(initializer.getOrder(), equalTo(Ordered.HIGHEST_PRECEDENCE));
+	}
 
+	@Test
+	public void customFlywayWithJpa() throws Exception {
+		registerAndRefresh(CustomFlywayWithJpaConfiguration.class,
+				EmbeddedDataSourceConfiguration.class, FlywayAutoConfiguration.class,
+				PropertyPlaceholderAutoConfiguration.class);
 	}
 
 	private void registerAndRefresh(Class<?>... annotatedClasses) {
@@ -204,6 +216,25 @@ public class FlywayAutoConfigurationTests {
 		}
 	}
 
+	@Configuration
+	protected static class CustomFlywayWithJpaConfiguration {
+
+		@Autowired
+		private DataSource dataSource;
+
+		@Bean
+		public Flyway flyway() {
+			return new Flyway();
+		}
+
+		@Bean
+		public LocalContainerEntityManagerFactoryBean entityManagerFactoryBean() {
+			return new EntityManagerFactoryBuilder(new HibernateJpaVendorAdapter(),
+					Collections.emptyMap(), null).dataSource(this.dataSource).build();
+		}
+
+	}
+
 	@Component
 	protected static class MockFlywayMigrationStrategy implements FlywayMigrationStrategy {