R2dbcCustomConversions could get some XxxConfigurer flavoured

[junyongz]

Know that @ConditionalOnMissingBean is there for us to override the whole bean, and eventually could provide any custom converters.

How about provide similar mechanism of WebFluxConfigurer, so just to provide the implementation of org.springframework.core.convert.converter.Converter would suffice.

spring-boot/spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/data/r2dbc/R2dbcDataAutoConfiguration.java

Line 106 in 9bf9442

Collections.emptyList());

	@Bean
	@ConditionalOnMissingBean
	public R2dbcCustomConversions r2dbcCustomConversions() {
		List<Object> converters = new ArrayList<>(this.dialect.getConverters());
		converters.addAll(R2dbcCustomConversions.STORE_CONVERTERS);
		return new R2dbcCustomConversions(
				CustomConversions.StoreConversions.of(this.dialect.getSimpleTypeHolder(), converters),
				Collections.emptyList());
	}

[wilkinsona]

Thanks for the suggestion, but I'm not sure exactly what you're looking for here. If you're proposing changes to the R2dbcCustomConversions API, it's part of Spring Data R2DBC and an issue would have to be opened over there. If you're proposing changes to Spring Boot, can you please elaborate? Perhaps you can share an example of what you'd like to be able to do.

[junyongz]

Maybe XxxConfigurer is not a good example.

Elaborate again.

	@Bean
	@ConditionalOnMissingBean
	public R2dbcCustomConversions r2dbcCustomConversions(ObjectProvider<UserConvertersProvider> convertersProvider) {
		List<Object> converters = new ArrayList<>(this.dialect.getConverters());
		converters.addAll(R2dbcCustomConversions.STORE_CONVERTERS);
		return new R2dbcCustomConversions(
				CustomConversions.StoreConversions.of(this.dialect.getSimpleTypeHolder(), converters),
				convertersProvider.getIfAvailable(() -> Collections.emptyList()).converters());
	}

        

Then, in user codes, just to provide the @Bean of UserConvertersProvider to provide the actual converters through converters() method

Actually, I am using Postgresql database, and one of the field of the table is JSON field, it is mapped to a POJO, so I need the converters to be registered, and what I found so far is to override R2dbcCustomConversions @Bean

[wilkinsona]

Thanks for the clarification. I'm not sure that it's worth introducing another type to provide converters. You can do this instead which is already pretty concise:

@Bean
R2dbcCustomConversions r2dbcCustomConversions(R2dbcDialect dialect) {
	return R2dbcCustomConversions.of(dialect, new ExampleConverter(), new AnotherExampleConverter());
}

The alternative would lead to application code that's something like this:

@Bean
UserConvertersProvider userConverters() {
	return () -> List.of(new ExampleConverter(), new AnotherExampleConverter());
}

I prefer the former. It's almost as concise and it doesn't result in an extra bean. Thanks anyway for the suggestion.

[junyongz]

Ok, I would go with this then, just thought of not to 'pollute' any @Bean defined in auto-configuration classes

Btw, It would be better to expose R2dbcDialect as a @Bean for below code to work.

@Bean
R2dbcCustomConversions r2dbcCustomConversions(R2dbcDialect dialect) {
	return R2dbcCustomConversions.of(dialect, new ExampleConverter(), new AnotherExampleConverter());
}

Thanks for your follow up.

[wilkinsona]

Here's my example without the dialect being a bean:

@Bean
R2dbcCustomConversions r2dbcCustomConversions(DatabaseClient client) {
	return R2dbcCustomConversions.of(DialectResolver.getDialect(client.getConnectionFactory()),
			new ExampleConverter(), new AnotherExampleConverter());
}

just thought of not to 'pollute' any @Bean defined in auto-configuration classes

This isn't pollution. It's exactly what the @ConditionalOnMissingBean annotation is intended to support.