Add builder for ConnectionFactoryInitializer

[mp911de]

ConnectionFactoryInitializer follows pretty much the pattern of DataSourceInitializer in the way the class is built. It would make sense to add a streamlined builder to improve configuration experience.

Right now, the initializer would be used as follows:

@Bean
public ConnectionFactoryInitializer initializer(ConnectionFactory connectionFactory) {
	ConnectionFactoryInitializer initializer = new ConnectionFactoryInitializer();
	initializer.setConnectionFactory(connectionFactory);
	initializer.setDatabasePopulator(new ResourceDatabasePopulator(new ClassPathResource("my-schema.sql"), new ClassPathResource("my-data.sql")));

	return initializer;
}

we should allow a streamlined construction that does not rely on setters but guides through the construction and that also helps with scanning resources through a ResourceLoader for script discovery using ant patterns.

[mp911de]

Here are a few ideas how we can streamline database initialization using an improved builder and by applying an annotation-driven model:

Annotation variant:

@Configuration(proxyBeanMethods = false)
@DatabaseInitializer("classpath:/my/scripts/init-h2-schema-*.sql")
@DatabaseInitializer(value = "classpath:/my/scripts/init-h2-data-*.sql", encoding = "UTF-8", ignoreFailures = IgnoreFailures.DROPS, connectionFactoryRef = "myCf")
@DatabaseCleaner("classpath:/my/scripts/init-h2-clean.sql")
static class Config {

}

Programmatic:

@Configuration(proxyBeanMethods = false)
static class Config {


	@Bean
	ConnectionFactoryInitializer initializer(ConnectionFactory connectionFactory, ResourceLoader loader){

		ConnectionFactoryInitializer initializer1 = ConnectionFactoryInitializer.builder()
				.initializeWith("classpath:/my/scripts/init-h2-schema-*.sql", loader)
				.cleanupWith("classpath:/my/scripts/init-h2-schema-*.sql", loader)
				.separator(";")
				.connectionFactory(connectionFactory)
				.scriptEncoding(StandardCharsets.UTF_8)
				.ignoreFailures(IgnoreFailures.DROPS)
				.build();

		ConnectionFactoryInitializer initializer2 = ConnectionFactoryInitializer.builder()
				.initializeWith(new ClassPathResource("classpath:/my/scripts/init-h2-schema-1.sql"), new ClassPathResource("classpath:/my/scripts/init-h2-schema-2.sql"))
				.cleanupWith(new ClassPathResource("classpath:/my/scripts/init-h2-schema-2.sql"))
				.connectionFactory(connectionFactory)
				.scriptEncoding(StandardCharsets.UTF_8)
				.ignoreFailures(IgnoreFailures.DROPS)
				.build();

		return initializer1;
	}
}

[mp911de]

This ticket is superseded with the migration of R2DBC core functionality into Spring Framework (Spring R2DBC).