BAEL-5323: Spring Boot with multiple data sources (#11741)

* BAEL-5323: Spring Boot with multiple data sources

* BAEL-5323: small fixes

* BAEL-5323: fix test class

* BAEL-5323: Refactor configuration classes

* BAEL-5323: Set proeprty to private

* BAEL-5323: rename test class to follow naming conventions

spring-boot-modules/spring-boot-multiple-datasources/src/main/java/com/baeldung/spring/datasources/MultipleDatasourcesApplication.java

@@ -0,0 +1,13 @@
+package com.baeldung.spring.datasources;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class MultipleDatasourcesApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(MultipleDatasourcesApplication.class, args);
+    }
+
+}

spring-boot-modules/spring-boot-multiple-datasources/src/main/java/com/baeldung/spring/datasources/todos/Todo.java

@@ -0,0 +1,48 @@
+package com.baeldung.spring.datasources.todos;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+
+@Entity
+public class Todo {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.AUTO)
+    private Long id;
+    private String title;
+    private boolean completed;
+
+    public Todo() {
+    }
+
+    public Todo(String title) {
+        this.title = title;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+    public boolean isCompleted() {
+        return completed;
+    }
+
+    public void setCompleted(boolean completed) {
+        this.completed = completed;
+    }
+
+}

spring-boot-modules/spring-boot-multiple-datasources/src/main/java/com/baeldung/spring/datasources/todos/TodoDatasourceConfiguration.java

@@ -0,0 +1,28 @@
+package com.baeldung.spring.datasources.todos;
+
+import org.springframework.boot.autoconfigure.jdbc.DataSourceProperties;
+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 javax.sql.DataSource;
+
+@Configuration
+public class TodoDatasourceConfiguration {
+
+    @Bean
+    @ConfigurationProperties("spring.datasource.todos")
+    public DataSourceProperties todosDataSourceProperties() {
+        return new DataSourceProperties();
+    }
+
+    @Bean
+    @Primary
+    public DataSource todosDataSource() {
+        return todosDataSourceProperties()
+          .initializeDataSourceBuilder()
+          .build();
+    }
+
+}

spring-boot-modules/spring-boot-multiple-datasources/src/main/java/com/baeldung/spring/datasources/todos/TodoJpaConfiguration.java

@@ -0,0 +1,40 @@
+package com.baeldung.spring.datasources.todos;
+
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.boot.orm.jpa.EntityManagerFactoryBuilder;
+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.LocalContainerEntityManagerFactoryBean;
+import org.springframework.transaction.PlatformTransactionManager;
+import org.springframework.transaction.annotation.EnableTransactionManagement;
+
+import javax.sql.DataSource;
+import java.util.Objects;
+
+@Configuration
+@EnableTransactionManagement
+@EnableJpaRepositories(
+  basePackageClasses = Todo.class,
+  entityManagerFactoryRef = "todosEntityManagerFactory",
+  transactionManagerRef = "todosTransactionManager"
+)
+public class TodoJpaConfiguration {
+
+    @Bean
+    public LocalContainerEntityManagerFactoryBean todosEntityManagerFactory(
+      @Qualifier("todosDataSource") DataSource dataSource,
+      EntityManagerFactoryBuilder builder) {
+        return builder
+          .dataSource(dataSource)
+          .packages(Todo.class)
+          .build();
+    }
+
+    @Bean
+    public PlatformTransactionManager todosTransactionManager(
+      @Qualifier("todosEntityManagerFactory") LocalContainerEntityManagerFactoryBean todosEntityManagerFactory) {
+        return new JpaTransactionManager(Objects.requireNonNull(todosEntityManagerFactory.getObject()));
+    }
+}

spring-boot-modules/spring-boot-multiple-datasources/src/main/java/com/baeldung/spring/datasources/todos/TodoRepository.java

@@ -0,0 +1,6 @@
+package com.baeldung.spring.datasources.todos;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface TodoRepository extends JpaRepository<Todo, Long> {
+}

spring-boot-modules/spring-boot-multiple-datasources/src/main/java/com/baeldung/spring/datasources/topics/Topic.java

@@ -0,0 +1,39 @@
+package com.baeldung.spring.datasources.topics;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+
+@Entity
+public class Topic {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.AUTO)
+    private Long id;
+    private String title;
+
+    public Topic() {
+    }
+
+    public Topic(String title) {
+        this.title = title;
+    }
+
+    public Long getId() {
+        return id;
+    }
+
+    public void setId(Long id) {
+        this.id = id;
+    }
+
+    public String getTitle() {
+        return title;
+    }
+
+    public void setTitle(String title) {
+        this.title = title;
+    }
+
+}

spring-boot-modules/spring-boot-multiple-datasources/src/main/java/com/baeldung/spring/datasources/topics/TopicDatasourceConfiguration.java

@@ -0,0 +1,26 @@
+package com.baeldung.spring.datasources.topics;
+
+import org.springframework.boot.autoconfigure.jdbc.DataSourceProperties;
+import org.springframework.boot.context.properties.ConfigurationProperties;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+import javax.sql.DataSource;
+
+@Configuration
+public class TopicDatasourceConfiguration {
+
+    @Bean
+    @ConfigurationProperties("spring.datasource.topics")
+    public DataSourceProperties topicsDataSourceProperties() {
+        return new DataSourceProperties();
+    }
+
+    @Bean
+    public DataSource topicsDataSource() {
+        return topicsDataSourceProperties()
+          .initializeDataSourceBuilder()
+          .build();
+    }
+
+}

spring-boot-modules/spring-boot-multiple-datasources/src/main/java/com/baeldung/spring/datasources/topics/TopicJpaConfiguration.java

@@ -0,0 +1,41 @@
+package com.baeldung.spring.datasources.topics;
+
+import org.springframework.beans.factory.annotation.Qualifier;
+import org.springframework.boot.orm.jpa.EntityManagerFactoryBuilder;
+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.LocalContainerEntityManagerFactoryBean;
+import org.springframework.transaction.PlatformTransactionManager;
+import org.springframework.transaction.annotation.EnableTransactionManagement;
+
+import javax.sql.DataSource;
+import java.util.Objects;
+
+@Configuration
+@EnableTransactionManagement
+@EnableJpaRepositories(
+  basePackageClasses = Topic.class,
+  entityManagerFactoryRef = "topicsEntityManagerFactory",
+  transactionManagerRef = "topicsTransactionManager"
+)
+public class TopicJpaConfiguration {
+
+    @Bean
+    public LocalContainerEntityManagerFactoryBean topicsEntityManagerFactory(
+      @Qualifier("topicsDataSource") DataSource dataSource,
+      EntityManagerFactoryBuilder builder
+    ) {
+        return builder
+          .dataSource(dataSource)
+          .packages(Topic.class)
+          .build();
+    }
+
+    @Bean
+    public PlatformTransactionManager topicsTransactionManager(
+      @Qualifier("topicsEntityManagerFactory") LocalContainerEntityManagerFactoryBean topicsEntityManagerFactory) {
+        return new JpaTransactionManager(Objects.requireNonNull(topicsEntityManagerFactory.getObject()));
+    }
+}

spring-boot-modules/spring-boot-multiple-datasources/src/main/java/com/baeldung/spring/datasources/topics/TopicRepository.java

@@ -0,0 +1,6 @@
+package com.baeldung.spring.datasources.topics;
+
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface TopicRepository extends JpaRepository<Topic, Long> {
+}

spring-boot-modules/spring-boot-multiple-datasources/src/main/resources/application.yml

@@ -0,0 +1,23 @@
+spring:
+  datasource:
+    todos:
+      url: jdbc:h2:./.local-db/todos;DB_CLOSE_DELAY=-1;MODE=DB2;AUTO_SERVER=TRUE
+      username: sa
+      password: null
+      driverClassName: org.h2.Driver
+    topics:
+      url: jdbc:h2:./.local-db/topics;DB_CLOSE_DELAY=-1;MODE=DB2;AUTO_SERVER=TRUE
+      username: sa
+      password: null
+      driverClassName: org.h2.Driver
+  h2:
+    console:
+      enabled: true
+      path: /h2-console
+  jpa:
+    generate-ddl: true
+    hibernate:
+      ddl-auto: update
+    properties:
+      hibernate:
+        dialect: org.hibernate.dialect.H2Dialect

spring-boot-modules/spring-boot-multiple-datasources/src/test/java/com/baeldung/spring/datasources/MultipleDatasourcesIntegrationTest.java

@@ -0,0 +1,39 @@
+package com.baeldung.spring.datasources;
+
+import com.baeldung.spring.datasources.todos.Todo;
+import com.baeldung.spring.datasources.todos.TodoRepository;
+import com.baeldung.spring.datasources.topics.Topic;
+import com.baeldung.spring.datasources.topics.TopicRepository;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+
+import java.util.Optional;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@DataJpaTest // no test database!
+class MultipleDatasourcesIntegrationTest {
+
+    @Autowired
+    TodoRepository todoRepo;
+    @Autowired
+    TopicRepository topicRepo;
+
+    @Test
+    void shouldSaveTodoToTodoDB() {
+        Todo todo = new Todo("test");
+        Todo saved =todoRepo.save(todo);
+        Optional<Todo> result= todoRepo.findById(saved.getId());
+        assertThat(result).isPresent();
+    }
+
+    @Test
+    void shouldSaveTopicToTopicDB() {
+        Topic todo = new Topic("test");
+        Topic saved =topicRepo.save(todo);
+        Optional<Topic> result= topicRepo.findById(saved.getId());
+        assertThat(result).isPresent();
+    }
+
+}