Use distinct JPA properties

Upgrade the sample to disable the JPA auto-configuration altogether and
use two different sets of JPA configuration.

This involve a bit of copy/paste for now but maybe we can improve that in
Spring Boot itself.

src/main/java/demo/DemoMultiEntityManagers.java

@@ -2,8 +2,9 @@
 
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.boot.autoconfigure.orm.jpa.HibernateJpaAutoConfiguration;
 
-@SpringBootApplication
+@SpringBootApplication(exclude = HibernateJpaAutoConfiguration.class)
 public class DemoMultiEntityManagers {
 
 	public static void main(String[] args) {

src/main/java/demo/customer/CustomerConfig.java

@@ -5,15 +5,21 @@
 
 import demo.customer.domain.Customer;
 
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder;
 import org.springframework.boot.autoconfigure.orm.jpa.EntityManagerFactoryBuilder;
+import org.springframework.boot.autoconfigure.orm.jpa.JpaProperties;
 import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Primary;
 import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
 import org.springframework.orm.jpa.JpaTransactionManager;
+import org.springframework.orm.jpa.JpaVendorAdapter;
 import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
+import org.springframework.orm.jpa.persistenceunit.PersistenceUnitManager;
+import org.springframework.orm.jpa.vendor.AbstractJpaVendorAdapter;
+import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
 
 @Configuration
 @EnableJpaRepositories(
@@ -22,6 +28,14 @@
 		basePackageClasses = Customer.class)
 public class CustomerConfig {
 
+	@Autowired(required = false)
+	private PersistenceUnitManager persistenceUnitManager;
+
+	@Bean
+	@ConfigurationProperties("app.customer.jpa")
+	public JpaProperties customerJpaProperties() {
+		return new JpaProperties();
+	}
 
 	@Bean
 	@Primary
@@ -32,7 +46,8 @@ public DataSource customerDataSource() {
 
 	@Bean
 	public LocalContainerEntityManagerFactoryBean customerEntityManager(
-			EntityManagerFactoryBuilder builder) {
+			JpaProperties customerJpaProperties) {
+		EntityManagerFactoryBuilder builder = createEntityManagerFactoryBuilder(customerJpaProperties);
 		return builder
 				.dataSource(customerDataSource())
 				.packages(Customer.class)
@@ -45,4 +60,20 @@ public LocalContainerEntityManagerFactoryBean customerEntityManager(
 	public JpaTransactionManager customerTransactionManager(EntityManagerFactory customerEntityManager) {
 		return new JpaTransactionManager(customerEntityManager);
 	}
+
+	private EntityManagerFactoryBuilder createEntityManagerFactoryBuilder(JpaProperties customerJpaProperties) {
+		JpaVendorAdapter jpaVendorAdapter = createJpaVendorAdapter(customerJpaProperties);
+		return new EntityManagerFactoryBuilder(
+				jpaVendorAdapter, customerJpaProperties, this.persistenceUnitManager);
+	}
+
+	private JpaVendorAdapter createJpaVendorAdapter(JpaProperties jpaProperties) {
+		AbstractJpaVendorAdapter adapter = new HibernateJpaVendorAdapter();
+		adapter.setShowSql(jpaProperties.isShowSql());
+		adapter.setDatabase(jpaProperties.getDatabase());
+		adapter.setDatabasePlatform(jpaProperties.getDatabasePlatform());
+		adapter.setGenerateDdl(jpaProperties.isGenerateDdl());
+		return adapter;
+	}
+
 }

src/main/java/demo/order/OrderConfig.java

@@ -5,14 +5,20 @@
 
 import demo.order.domain.Order;
 
+import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.jdbc.DataSourceBuilder;
 import org.springframework.boot.autoconfigure.orm.jpa.EntityManagerFactoryBuilder;
+import org.springframework.boot.autoconfigure.orm.jpa.JpaProperties;
 import org.springframework.boot.context.properties.ConfigurationProperties;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
 import org.springframework.orm.jpa.JpaTransactionManager;
+import org.springframework.orm.jpa.JpaVendorAdapter;
 import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
+import org.springframework.orm.jpa.persistenceunit.PersistenceUnitManager;
+import org.springframework.orm.jpa.vendor.AbstractJpaVendorAdapter;
+import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
 
 @Configuration
 @EnableJpaRepositories(
@@ -21,6 +27,15 @@
 		basePackageClasses = Order.class)
 public class OrderConfig {
 
+	@Autowired(required = false)
+	private PersistenceUnitManager persistenceUnitManager;
+
+	@Bean
+	@ConfigurationProperties("app.order.jpa")
+	public JpaProperties orderJpaProperties() {
+		return new JpaProperties();
+	}
+
 	@Bean
 	@ConfigurationProperties(prefix = "app.order.datasource")
 	public DataSource orderDataSource() {
@@ -29,7 +44,8 @@ public DataSource orderDataSource() {
 
 	@Bean
 	public LocalContainerEntityManagerFactoryBean orderEntityManager(
-			EntityManagerFactoryBuilder builder) {
+			JpaProperties orderJpaProperties) {
+		EntityManagerFactoryBuilder builder = createEntityManagerFactoryBuilder(orderJpaProperties);
 		return builder
 				.dataSource(orderDataSource())
 				.packages(Order.class)
@@ -42,4 +58,19 @@ public JpaTransactionManager orderTransactionManager(EntityManagerFactory orderE
 		return new JpaTransactionManager(orderEntityManager);
 	}
 
+	private EntityManagerFactoryBuilder createEntityManagerFactoryBuilder(JpaProperties customerJpaProperties) {
+		JpaVendorAdapter jpaVendorAdapter = createJpaVendorAdapter(customerJpaProperties);
+		return new EntityManagerFactoryBuilder(
+				jpaVendorAdapter, customerJpaProperties, this.persistenceUnitManager);
+	}
+
+	private JpaVendorAdapter createJpaVendorAdapter(JpaProperties jpaProperties) {
+		AbstractJpaVendorAdapter adapter = new HibernateJpaVendorAdapter();
+		adapter.setShowSql(jpaProperties.isShowSql());
+		adapter.setDatabase(jpaProperties.getDatabase());
+		adapter.setDatabasePlatform(jpaProperties.getDatabasePlatform());
+		adapter.setGenerateDdl(jpaProperties.isGenerateDdl());
+		return adapter;
+	}
+
 }

src/main/resources/application.properties

@@ -1,7 +1,7 @@
-spring.jpa.properties.hibernate.hbm2ddl.auto=create
-
 app.customer.datasource.url=jdbc:h2:mem:customers;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=FALSE
 app.customer.datasource.driver-class-name=org.h2.Driver
+app.customer.jpa.properties.hibernate.hbm2ddl.auto=create
 
 app.order.datasource.url=jdbc:h2:mem:orders;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=FALSE
 app.order.datasource.driver-class-name=org.h2.Driver
+app.order.jpa.properties.hibernate.hbm2ddl.auto=create