[BAEL-2048] Spring Data JPA multiple databases article

spring-data-jpa/src/main/java/org/baeldung/config/ProductConfig.java

@@ -0,0 +1,68 @@
+package org.baeldung.config;
+
+import java.util.HashMap;
+
+import javax.sql.DataSource;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.PropertySource;
+import org.springframework.core.env.Environment;
+import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
+import org.springframework.jdbc.datasource.DriverManagerDataSource;
+import org.springframework.orm.jpa.JpaTransactionManager;
+import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
+import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
+import org.springframework.transaction.PlatformTransactionManager;
+
+import com.google.common.base.Preconditions;
+
+@Configuration
+@PropertySource({ "classpath:persistence-multiple-db.properties" })
+@EnableJpaRepositories(basePackages = "org.baeldung.persistence.multiple.dao.product", entityManagerFactoryRef = "productEntityManager", transactionManagerRef = "productTransactionManager")
+public class ProductConfig {
+    @Autowired
+    private Environment env;
+
+    public ProductConfig() {
+        super();
+    }
+
+    //
+
+    @Bean
+    public LocalContainerEntityManagerFactoryBean productEntityManager() {
+        final LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
+        em.setDataSource(productDataSource());
+        em.setPackagesToScan(new String[] { "org.baeldung.persistence.multiple.model.product" });
+
+        final HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
+        em.setJpaVendorAdapter(vendorAdapter);
+        final HashMap<String, Object> properties = new HashMap<String, Object>();
+        properties.put("hibernate.hbm2ddl.auto", env.getProperty("hibernate.hbm2ddl.auto"));
+        properties.put("hibernate.dialect", env.getProperty("hibernate.dialect"));
+        em.setJpaPropertyMap(properties);
+
+        return em;
+    }
+
+    @Bean
+    public DataSource productDataSource() {
+        final DriverManagerDataSource dataSource = new DriverManagerDataSource();
+        dataSource.setDriverClassName(Preconditions.checkNotNull(env.getProperty("jdbc.driverClassName")));
+        dataSource.setUrl(Preconditions.checkNotNull(env.getProperty("product.jdbc.url")));
+        dataSource.setUsername(Preconditions.checkNotNull(env.getProperty("jdbc.user")));
+        dataSource.setPassword(Preconditions.checkNotNull(env.getProperty("jdbc.pass")));
+
+        return dataSource;
+    }
+
+    @Bean
+    public PlatformTransactionManager productTransactionManager() {
+        final JpaTransactionManager transactionManager = new JpaTransactionManager();
+        transactionManager.setEntityManagerFactory(productEntityManager().getObject());
+        return transactionManager;
+    }
+
+}

spring-data-jpa/src/main/java/org/baeldung/config/UserConfig.java

@@ -0,0 +1,72 @@
+package org.baeldung.config;
+
+import java.util.HashMap;
+
+import javax.sql.DataSource;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.Primary;
+import org.springframework.context.annotation.PropertySource;
+import org.springframework.core.env.Environment;
+import org.springframework.data.jpa.repository.config.EnableJpaRepositories;
+import org.springframework.jdbc.datasource.DriverManagerDataSource;
+import org.springframework.orm.jpa.JpaTransactionManager;
+import org.springframework.orm.jpa.LocalContainerEntityManagerFactoryBean;
+import org.springframework.orm.jpa.vendor.HibernateJpaVendorAdapter;
+import org.springframework.transaction.PlatformTransactionManager;
+
+import com.google.common.base.Preconditions;
+
+@Configuration
+@PropertySource({ "classpath:persistence-multiple-db.properties" })
+@EnableJpaRepositories(basePackages = "org.baeldung.persistence.multiple.dao.user", entityManagerFactoryRef = "userEntityManager", transactionManagerRef = "userTransactionManager")
+public class UserConfig {
+    @Autowired
+    private Environment env;
+
+    public UserConfig() {
+        super();
+    }
+
+    //
+
+    @Primary
+    @Bean
+    public LocalContainerEntityManagerFactoryBean userEntityManager() {
+        final LocalContainerEntityManagerFactoryBean em = new LocalContainerEntityManagerFactoryBean();
+        em.setDataSource(userDataSource());
+        em.setPackagesToScan(new String[] { "org.baeldung.persistence.multiple.model.user" });
+
+        final HibernateJpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
+        em.setJpaVendorAdapter(vendorAdapter);
+        final HashMap<String, Object> properties = new HashMap<String, Object>();
+        properties.put("hibernate.hbm2ddl.auto", env.getProperty("hibernate.hbm2ddl.auto"));
+        properties.put("hibernate.dialect", env.getProperty("hibernate.dialect"));
+        em.setJpaPropertyMap(properties);
+
+        return em;
+    }
+
+    @Primary
+    @Bean
+    public DataSource userDataSource() {
+        final DriverManagerDataSource dataSource = new DriverManagerDataSource();
+        dataSource.setDriverClassName(Preconditions.checkNotNull(env.getProperty("jdbc.driverClassName")));
+        dataSource.setUrl(Preconditions.checkNotNull(env.getProperty("user.jdbc.url")));
+        dataSource.setUsername(Preconditions.checkNotNull(env.getProperty("jdbc.user")));
+        dataSource.setPassword(Preconditions.checkNotNull(env.getProperty("jdbc.pass")));
+
+        return dataSource;
+    }
+
+    @Primary
+    @Bean
+    public PlatformTransactionManager userTransactionManager() {
+        final JpaTransactionManager transactionManager = new JpaTransactionManager();
+        transactionManager.setEntityManagerFactory(userEntityManager().getObject());
+        return transactionManager;
+    }
+
+}

spring-data-jpa/src/main/java/org/baeldung/persistence/multiple/dao/product/ProductRepository.java

@@ -0,0 +1,8 @@
+package org.baeldung.persistence.multiple.dao.product;
+
+import org.baeldung.persistence.multiple.model.product.Product;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface ProductRepository extends JpaRepository<Product, Integer> {
+
+}

spring-data-jpa/src/main/java/org/baeldung/persistence/multiple/dao/user/PossessionRepository.java

@@ -0,0 +1,8 @@
+package org.baeldung.persistence.multiple.dao.user;
+
+import org.baeldung.persistence.multiple.model.user.Possession;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface PossessionRepository extends JpaRepository<Possession, Long> {
+
+}

spring-data-jpa/src/main/java/org/baeldung/persistence/multiple/dao/user/UserRepository.java

@@ -0,0 +1,8 @@
+package org.baeldung.persistence.multiple.dao.user;
+
+import org.baeldung.persistence.multiple.model.user.User;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface UserRepository extends JpaRepository<User, Integer> {
+
+}

spring-data-jpa/src/main/java/org/baeldung/persistence/multiple/model/product/Product.java

@@ -0,0 +1,52 @@
+package org.baeldung.persistence.multiple.model.product;
+
+import javax.persistence.Entity;
+import javax.persistence.Id;
+import javax.persistence.Table;
+
+@Entity
+@Table(schema = "spring_jpa_product")
+public class Product {
+
+    @Id
+    private int id;
+
+    private String name;
+
+    private double price;
+
+    public Product() {
+        super();
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(final int id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(final String name) {
+        this.name = name;
+    }
+
+    public double getPrice() {
+        return price;
+    }
+
+    public void setPrice(final double price) {
+        this.price = price;
+    }
+
+    @Override
+    public String toString() {
+        final StringBuilder builder = new StringBuilder();
+        builder.append("Product [name=").append(name).append(", id=").append(id).append("]");
+        return builder.toString();
+    }
+}

spring-data-jpa/src/main/java/org/baeldung/persistence/multiple/model/user/Possession.java

@@ -0,0 +1,86 @@
+package org.baeldung.persistence.multiple.model.user;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.Table;
+
+@Entity
+@Table(schema = "spring_jpa_user")
+public class Possession {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private long id;
+
+    private String name;
+
+    public Possession() {
+        super();
+    }
+
+    public Possession(final String name) {
+        super();
+
+        this.name = name;
+    }
+
+    public long getId() {
+        return id;
+    }
+
+    public void setId(final int id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(final String name) {
+        this.name = name;
+    }
+
+    @Override
+    public int hashCode() {
+        final int prime = 31;
+        int result = 1;
+        result = (prime * result) + (int) (id ^ (id >>> 32));
+        result = (prime * result) + ((name == null) ? 0 : name.hashCode());
+        return result;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (obj == null) {
+            return false;
+        }
+        if (getClass() != obj.getClass()) {
+            return false;
+        }
+        final Possession other = (Possession) obj;
+        if (id != other.id) {
+            return false;
+        }
+        if (name == null) {
+            if (other.name != null) {
+                return false;
+            }
+        } else if (!name.equals(other.name)) {
+            return false;
+        }
+        return true;
+    }
+
+    @Override
+    public String toString() {
+        final StringBuilder builder = new StringBuilder();
+        builder.append("Possesion [id=").append(id).append(", name=").append(name).append("]");
+        return builder.toString();
+    }
+
+}

spring-data-jpa/src/main/java/org/baeldung/persistence/multiple/model/user/User.java

@@ -0,0 +1,81 @@
+package org.baeldung.persistence.multiple.model.user;
+
+import java.util.List;
+
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.OneToMany;
+import javax.persistence.Table;
+
+@Entity
+@Table(schema = "spring_jpa_user")
+public class User {
+
+    @Id
+    @GeneratedValue(strategy = GenerationType.IDENTITY)
+    private int id;
+
+    private String name;
+
+    @Column(unique = true, nullable = false)
+    private String email;
+
+    private int age;
+
+    @OneToMany
+    List<Possession> possessionList;
+
+    public User() {
+        super();
+    }
+
+    public int getId() {
+        return id;
+    }
+
+    public void setId(final int id) {
+        this.id = id;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public void setName(final String name) {
+        this.name = name;
+    }
+
+    public String getEmail() {
+        return email;
+    }
+
+    public void setEmail(final String email) {
+        this.email = email;
+    }
+
+    public int getAge() {
+        return age;
+    }
+
+    public void setAge(final int age) {
+        this.age = age;
+    }
+
+    public List<Possession> getPossessionList() {
+        return possessionList;
+    }
+
+    public void setPossessionList(List<Possession> possessionList) {
+        this.possessionList = possessionList;
+    }
+
+    @Override
+    public String toString() {
+        final StringBuilder builder = new StringBuilder();
+        builder.append("User [name=").append(name).append(", id=").append(id).append("]");
+        return builder.toString();
+    }
+}

spring-data-jpa/src/main/resources/persistence-multiple-db.properties

@@ -0,0 +1,13 @@
+# jdbc.X
+jdbc.driverClassName=org.h2.Driver
+user.jdbc.url=jdbc:h2:mem:spring_jpa_user;DB_CLOSE_DELAY=-1;INIT=CREATE SCHEMA IF NOT EXISTS SPRING_JPA_USER
+product.jdbc.url=jdbc:h2:mem:spring_jpa_product;DB_CLOSE_DELAY=-1;INIT=CREATE SCHEMA IF NOT EXISTS SPRING_JPA_PRODUCT
+jdbc.user=sa
+jdbc.pass=
+
+# hibernate.X
+hibernate.dialect=org.hibernate.dialect.H2Dialect
+hibernate.show_sql=false
+hibernate.hbm2ddl.auto=create-drop
+hibernate.cache.use_second_level_cache=false
+hibernate.cache.use_query_cache=false

spring-data-jpa/src/test/java/org/baeldung/persistence/service/JpaMultipleDBIntegrationTest.java

@@ -0,0 +1,97 @@
+package org.baeldung.persistence.service;
+
+import org.baeldung.config.ProductConfig;
+import org.baeldung.config.UserConfig;
+import org.baeldung.persistence.multiple.dao.product.ProductRepository;
+import org.baeldung.persistence.multiple.dao.user.PossessionRepository;
+import org.baeldung.persistence.multiple.dao.user.UserRepository;
+import org.baeldung.persistence.multiple.model.product.Product;
+import org.baeldung.persistence.multiple.model.user.Possession;
+import org.baeldung.persistence.multiple.model.user.User;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.dao.DataIntegrityViolationException;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
+import org.springframework.transaction.annotation.EnableTransactionManagement;
+import org.springframework.transaction.annotation.Transactional;
+
+import java.util.Collections;
+import java.util.Optional;
+
+import static org.junit.Assert.*;
+
+@RunWith(SpringJUnit4ClassRunner.class)
+@ContextConfiguration(classes = { UserConfig.class, ProductConfig.class })
+@EnableTransactionManagement
+@DirtiesContext
+public class JpaMultipleDBIntegrationTest {
+
+    @Autowired
+    private UserRepository userRepository;
+
+    @Autowired
+    private PossessionRepository possessionRepository;
+
+    @Autowired
+    private ProductRepository productRepository;
+
+    // tests
+
+    @Test
+    @Transactional("userTransactionManager")
+    public void whenCreatingUser_thenCreated() {
+        User user = new User();
+        user.setName("John");
+        user.setEmail("john@test.com");
+        user.setAge(20);
+        Possession p = new Possession("sample");
+        p = possessionRepository.save(p);
+        user.setPossessionList(Collections.singletonList(p));
+        user = userRepository.save(user);
+        final Optional<User> result = userRepository.findById(user.getId());
+        assertTrue(result.isPresent());
+        System.out.println(result.get().getPossessionList());
+        assertEquals(1, result.get().getPossessionList().size());
+    }
+
+    @Test
+    @Transactional("userTransactionManager")
+    public void whenCreatingUsersWithSameEmail_thenRollback() {
+        User user1 = new User();
+        user1.setName("John");
+        user1.setEmail("john@test.com");
+        user1.setAge(20);
+        user1 = userRepository.save(user1);
+        assertTrue(userRepository.findById(user1.getId()).isPresent());
+
+        User user2 = new User();
+        user2.setName("Tom");
+        user2.setEmail("john@test.com");
+        user2.setAge(10);
+        try {
+            user2 = userRepository.save(user2);
+            userRepository.flush();
+            fail("DataIntegrityViolationException should be thrown!");
+        } catch (final DataIntegrityViolationException e) {
+            // Expected
+        } catch (final Exception e) {
+            fail("DataIntegrityViolationException should be thrown, instead got: " + e);
+        }
+    }
+
+    @Test
+    @Transactional("productTransactionManager")
+    public void whenCreatingProduct_thenCreated() {
+        Product product = new Product();
+        product.setName("Book");
+        product.setId(2);
+        product.setPrice(20);
+        product = productRepository.save(product);
+
+        assertTrue(productRepository.findById(product.getId()).isPresent());
+    }
+
+}