Spring Boot has introduced the concept of configurer when users would like to create custom instances of a given type whilst retaining the behavior of auto-configuration. They can decide to tune settings before and after calling a configure method. They also can pass a sub-class of the type to configure (if possible) to get exactly what the auto-configuration produced, but with a type that may provide customization of protected methods.
I believe #5138 is the issue that started this pattern.
Looking at the codebase, we have used this in other parts but some usage are now inconsistent. Here's a summary of where we are:
- JMS has kept the original idea with a
configure method that takes the factory and a ConnectionFactory. The default instance is created by injecting the configurer and calling configure on it.
- Kafka is problematic as a number of customizers are applied manually which means a configure won't do the same thing as the auto-configuration. Users are reporting, for instance, that they lose observability when using this pattern.
- Rabbit:
- Redis is new and is following the pattern for JMS
RestClientBuilderConfigurer is sane, with the default builder created by a one-liner from the configurer.RestTemplateBuilderConfigurer is sane, with the default builder created by a one-liner from the configurer.
Rabbit and Kafka needs some work to re-align what we intended with the configurer pattern.
Spring Boot has introduced the concept of configurer when users would like to create custom instances of a given type whilst retaining the behavior of auto-configuration. They can decide to tune settings before and after calling a
configuremethod. They also can pass a sub-class of the type to configure (if possible) to get exactly what the auto-configuration produced, but with a type that may provide customization of protected methods.I believe #5138 is the issue that started this pattern.
Looking at the codebase, we have used this in other parts but some usage are now inconsistent. Here's a summary of where we are:
configuremethod that takes the factory and aConnectionFactory. The default instance is created by injecting the configurer and calling configure on it.ContainerCustomizerthat is not applied by the configurer.RabbitTemplateCustomizerthat is not applied by the configurer.RestClientBuilderConfigureris sane, with the default builder created by a one-liner from the configurer.RestTemplateBuilderConfigureris sane, with the default builder created by a one-liner from the configurer.Rabbit and Kafka needs some work to re-align what we intended with the configurer pattern.