how can i parameterize datasource properties on Spring 4?

Question

I am using Spring 4.16. I want to parameterize my persistence data. This is my config right now:

@Configuration
@EnableTransactionManagement
public class PersistenceConfiguration {

    @Bean
    public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
        LocalContainerEntityManagerFactoryBean entityManager = new LocalContainerEntityManagerFactoryBean();
        entityManager.setDataSource(this.dataSource());
        entityManager.setPackagesToScan(new String[] {"com.example.movies.domain"});
        JpaVendorAdapter vendorAdapter = new HibernateJpaVendorAdapter();
        entityManager.setJpaVendorAdapter(vendorAdapter);
        entityManager.setJpaProperties(this.properties());
        return entityManager;
    }

@Bean
public DataSource dataSource() {
    DriverManagerDataSource dataSource = new DriverManagerDataSource();
    dataSource.setDriverClassName("com.mysql.jdbc.Driver");
    dataSource.setUrl("jdbc:mysql://localhost:3306/sarasa_db");
    dataSource.setUsername("root");
    dataSource.setPassword("mypassword");
    return dataSource;
}

    @Bean
    public PlatformTransactionManager transactionManager(EntityManagerFactory emf) {
        JpaTransactionManager transactionManager = new JpaTransactionManager();
        transactionManager.setEntityManagerFactory(emf);
        return transactionManager;
    }

    @Bean
    public PersistenceExceptionTranslationPostProcessor exceptionTranslation() {
        return new PersistenceExceptionTranslationPostProcessor();
    }

    private Properties properties() {
        Properties properties = new Properties();
        properties.setProperty("hibernate.hbm2ddl.auto", "update");
        properties.setProperty("hibernate.dialect", "org.hibernate.dialect.MySQL5Dialect");
        properties.setProperty("hibernate.show_sql", "false");
        return properties;
    }

}

And i want to parameterize on my application.properties all things i can. First of all, i want to put in datasource properties (so as i was reading, is possible that spring builds my datasource automatically, but apparently that is only using JdbcTemplate...):

spring.datasource.driverClassName=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/sarasa_db
spring.datasource.username=root
spring.datasource.password=mypassword

And, if it's possible, all the Properties's properties, which i couldn't find nothing in doc

Do you know how could i do it ?

---

EDIT

This is my DAO implementation

@Configuration
@Import(PersistenceConfiguration.class)
public class DAOConfiguration {

    @PersistenceContext
    private EntityManager entityManager;

    @Bean
    public ClientDAO clientDAO() {
        SimpleJpaRepository<Client, String> support = this.getSimpleJpaRepository(Client.class);
        return new MySQLClientDAO(support);
    }

    @Bean
    @Scope(BeanDefinition.SCOPE_PROTOTYPE)
    @Description("Hibernate repository helper")
    protected <T> SimpleJpaRepository<T, String> getSimpleJpaRepository(Class<T> domainClass) {
        return new SimpleJpaRepository<T, String>(domainClass, this.entityManager);
    }

}

Answer 1

You could do something like this:

First define PropertySourcesPlaceholderConfigurer bean somewhere in your Spring configuration:

@Bean
public static PropertySourcesPlaceholderConfigurer propertyPlaceholderConfigurer() {
    PropertySourcesPlaceholderConfigurer ppc = new PropertySourcesPlaceholderConfigurer();
    ppc.setLocation(new ClassPathResource("application.properties"));
    return ppc;
}

This configuration assumes that application.properties file is placed at the root of your classpath.

After setting up the property placeholder configurer you can access the properties in your database configuration class like so:

@Configuration
@EnableTransactionManagement
public class PersistenceConfiguration {

    @Value("${spring.datasource.url}")
    private String jdbcUrl;
    // ...

    @Bean
    public DataSource dataSource() {
       DriverManagerDataSource dataSource = new DriverManagerDataSource();
       dataSource.setUrl(jdbcUrl);
       // ...
    }
}

If you want an easy way to parametrize all properties, you should take a look at Spring Boot . It uses the application.properties file to automatically create data source with those properties, and many other things. This is probably the automatic datasource creation you mentioned in your question.