BAEL-2545 - Configuring a DataSource Programatically in Spring Boot (#6139)

* Initial Commit

* Update UserRepositoryIntegrationTest.java

* Update UserRepositoryIntegrationTest

persistence-modules/spring-boot-persistence/src/main/java/com/baeldung/springbootdatasourceconfig/application/Application.java

@@ -0,0 +1,27 @@
+package com.baeldung.springbootdatasourceconfig.application;
+
+import com.baeldung.springbootdatasourceconfig.application.entities.User;
+import com.baeldung.springbootdatasourceconfig.application.repositories.UserRepository;
+import org.springframework.boot.CommandLineRunner;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+
+@SpringBootApplication
+public class Application {
+
+    public static void main(String[] args) {
+        SpringApplication.run(Application.class, args);
+    }
+
+    @Bean
+    public CommandLineRunner run(UserRepository userRepository) throws Exception {
+        return (String[] args) -> {
+            User user1 = new User("John", "john@domain.com");
+            User user2 = new User("Julie", "julie@domain.com");
+            userRepository.save(user1);
+            userRepository.save(user2);
+            userRepository.findAll().forEach(user -> System.out.println(user.getName()));
+        };
+    }
+}

persistence-modules/spring-boot-persistence/src/main/java/com/baeldung/springbootdatasourceconfig/application/datasources/DataSourceBean.java

@@ -0,0 +1,20 @@
+package com.baeldung.springbootdatasourceconfig.application.datasources;
+
+import javax.sql.DataSource;
+import org.springframework.boot.jdbc.DataSourceBuilder;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+@Configuration
+public class DataSourceBean {
+    
+    @Bean
+    public DataSource getDataSource() {
+        DataSourceBuilder dataSourceBuilder = DataSourceBuilder.create();
+        dataSourceBuilder.driverClassName("org.h2.Driver");
+        dataSourceBuilder.url("jdbc:h2:mem:test");
+        dataSourceBuilder.username("SA");
+        dataSourceBuilder.password("");
+        return dataSourceBuilder.build();
+    }
+}

persistence-modules/spring-boot-persistence/src/main/java/com/baeldung/springbootdatasourceconfig/application/entities/User.java

@@ -0,0 +1,46 @@
+package com.baeldung.springbootdatasourceconfig.application.entities;
+
+import javax.persistence.Entity;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.Table;
+
+@Entity
+@Table(name = "users")
+public class User {
+    
+    @Id
+    @GeneratedValue(strategy = GenerationType.AUTO)
+    private long id;
+    private String name;
+    private String email;
+    
+    public User(){}
+    
+    public User(String name, String email) {
+        this.name = name;
+        this.email = email;
+    }
+    
+    public String getName() {
+        return name;
+    }
+
+    public void setName(String name) {
+        this.name = name;
+    }
+
+    public String getEmail() {
+        return email;
+    }
+
+    public void setEmail(String email) {
+        this.email = email;
+    }
+
+    @Override
+    public String toString() {
+        return "User{" + "id=" + id + ", name=" + name + ", email=" + email + '}';
+    }    
+}

persistence-modules/spring-boot-persistence/src/main/java/com/baeldung/springbootdatasourceconfig/application/repositories/UserRepository.java

@@ -0,0 +1,8 @@
+package com.baeldung.springbootdatasourceconfig.application.repositories;
+
+import com.baeldung.springbootdatasourceconfig.application.entities.User;
+import org.springframework.data.repository.CrudRepository;
+import org.springframework.stereotype.Repository;
+
+@Repository
+public interface UserRepository extends CrudRepository<User, Long> {}

persistence-modules/spring-boot-persistence/src/test/java/com/baeldung/springbootdatasourceconfig/tests/UserRepositoryIntegrationTest.java

@@ -0,0 +1,28 @@
+package com.baeldung.springbootdatasourceconfig.tests;
+
+import com.baeldung.springbootdatasourceconfig.application.entities.User;
+import com.baeldung.springbootdatasourceconfig.application.repositories.UserRepository;
+import java.util.List;
+import java.util.Optional;
+import org.junit.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import static org.assertj.core.api.Assertions.assertThat;
+import org.junit.runner.RunWith;
+import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
+import org.springframework.test.context.junit4.SpringRunner;
+
+@RunWith(SpringRunner.class)
+@DataJpaTest
+public class UserRepositoryIntegrationTest {
+    
+    @Autowired
+    private UserRepository userRepository;
+    
+    @Test
+    public void whenCalledSave_thenCorrectNumberOfUsers() {
+        userRepository.save(new User("Bob", "bob@domain.com"));
+        List<User> users = (List<User>) userRepository.findAll();
+        
+        assertThat(users.size()).isEqualTo(1);
+    }
+}