How can i call/execute the "@configuration" java class in spring project?

[Arun Singh Raaj]

Hello guys,
I don't know how to invoke the configuration file in spring-data jpa based application. How does this file execute by spring container when the application starts?

thanks in advance.


Here is the code of that file=

@Configuration
@EnableTransactionManagement  
@EnableJpaRepositories(basePackages = {
        "Persistence_Layer"
})    
class PersistenceContext {
    //Configure the required beans here
	
	 @Bean(destroyMethod = "close")
	    DataSource dataSource(Environment env) {
		     DriverManagerDataSource ds = new DriverManagerDataSource();	        
		    ds.setDriverClassName(env.getRequiredProperty("db.driver"));
		    ds.setUrl(env.getRequiredProperty("db.url"));
		    ds.setUsername(env.getRequiredProperty("db.username"));
		    ds.setPassword(env.getRequiredProperty("db.password"));
	 
	        return ds;
	    }
	     
	 
	 //configure EntityManager
	 @Bean
	    LocalContainerEntityManagerFactoryBean entityManagerFactory(DataSource dataSource, 
	                                                                Environment env) {
	        LocalContainerEntityManagerFactoryBean entityManagerFactoryBean = new LocalContainerEntityManagerFactoryBean();
	        entityManagerFactoryBean.setDataSource(dataSource);
	        entityManagerFactoryBean.setJpaVendorAdapter(new HibernateJpaVendorAdapter());
	        entityManagerFactoryBean.setPackagesToScan("Business_Layer");
	 
	        Properties jpaProperties = new Properties();
	     
	        //Configures the used database dialect. This allows Hibernate to create SQL
	        //that is optimized for the used database.
	        jpaProperties.put("hibernate.dialect", env.getRequiredProperty("hibernate.dialect"));
	 
	        //Specifies the action that is invoked to the database when the Hibernate
	        //SessionFactory is created or closed.
	        jpaProperties.put("hibernate.hbm2ddl.auto", 
	                env.getRequiredProperty("hibernate.hbm2ddl.auto")
	        );
	 
	        //Configures the naming strategy that is used when Hibernate creates
	        //new database objects and schema elements
	        jpaProperties.put("hibernate.ejb.naming_strategy", 
	                env.getRequiredProperty("hibernate.ejb.naming_strategy")
	        );
	 
	        //If the value of this property is true, Hibernate writes all SQL
	        //statements to the console.
	        jpaProperties.put("hibernate.show_sql", 
	                env.getRequiredProperty("hibernate.show_sql")
	        );
	 
	        //If the value of this property is true, Hibernate will format the SQL
	        //that is written to the console.
	        jpaProperties.put("hibernate.format_sql", 
	                env.getRequiredProperty("hibernate.format_sql")
	        );
	 
	        entityManagerFactoryBean.setJpaProperties(jpaProperties);
	 
	        return entityManagerFactoryBean;
	    }
	 
	 
	 //transaction manager bean
	  @Bean
	    JpaTransactionManager transactionManager(EntityManagerFactory entityManagerFactory) {
	        JpaTransactionManager transactionManager = new JpaTransactionManager();
	        transactionManager.setEntityManagerFactory(entityManagerFactory);
	        return transactionManager;
	    }
	 
	    //Add the other beans here
}

[Daniel Demesmaecker]

public static void main(String[] args) {
   AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext();

   ctx.register(AppConfig.class, Config.class);
   ctx.refresh();

   MyService myService = ctx.getBean(MyService.class);
   myService.doStuff();
}

[Arun Singh Raaj]

thanks Daniel