#392 - Added example for deferred repository initialization.

jpa/deferred/src/main/java/example/Application.java

@@ -0,0 +1,88 @@
+/*
+ * Copyright 2018 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
+ *
+ *      http://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 example;
+
+import example.model.Customer;
+
+import javax.sql.DataSource;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Profile;
+import org.springframework.core.env.Environment;
+import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
+import org.springframework.data.repository.config.BootstrapMode;
+import org.springframework.orm.jpa.JpaVendorAdapter;
+import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
+import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
+
+@SpringBootApplication
+public class Application {
+
+	public static void main(String[] args) {
+		SpringApplication.run(Application.class);
+	}
+
+	/**
+	 * Configures a {@link LocalContainerEntityManagerFactoryBean} to use background initialization for the {@code lazy}
+	 * and {@code deferred} profiles.
+	 *
+	 * @author Oliver Gierke
+	 */
+	@Configuration
+	@Profile({ "lazy", "deferred" })
+	static class LazyJpaConfiguration {
+
+		@Bean
+		public LocalContainerEntityManagerFactoryBean entityManagerFactory(JpaVendorAdapter jpaVendorAdapter,
+				DataSource dataSource, Environment environment) {
+
+			ThreadPoolTaskExecutor threadPoolTaskExecutor = new ThreadPoolTaskExecutor();
+			threadPoolTaskExecutor.setDaemon(true);
+			threadPoolTaskExecutor.afterPropertiesSet();
+
+			LocalContainerEntityManagerFactoryBean emf = new LocalContainerEntityManagerFactoryBean();
+			emf.setBootstrapExecutor(threadPoolTaskExecutor);
+			emf.setDataSource(dataSource);
+			emf.setJpaVendorAdapter(jpaVendorAdapter);
+			emf.setPackagesToScan(Customer.class.getPackage().getName());
+
+			return emf;
+		}
+	}
+
+	/**
+	 * Bootstraps Spring Data JPA in lazy mode if the {@code lazy} profile is activated.
+	 *
+	 * @author Oliver Gierke
+	 */
+	@Profile("lazy")
+	@Configuration
+	@EnableJpaRepositories(bootstrapMode = BootstrapMode.LAZY)
+	static class LazyRepositoryConfiguration {}
+
+	/**
+	 * Bootstraps Spring Data JPA in deferred mode if the {@code deferred} profile is activated.
+	 *
+	 * @author Oliver Gierke
+	 */
+	@Profile("deferred")
+	@Configuration
+	@EnableJpaRepositories(bootstrapMode = BootstrapMode.DEFERRED)
+	static class DeferredRepositoryConfiguration {}
+}