Which RabbitAdmin is selected by default if "setAdminsThatShouldDeclare" is not called?

Question

I want to declare Queue and Exchange, which RabbitAdmin instance is being selected if I do not call the setAdminsThatShouldDeclare on Queue or Exchange:

@Bean
public Queue queue() {
    Queue queue = new Queue("foo");
    // queue.setAdminsThatShouldDeclare(admin1()); 
    return queue;
}

@Bean
public Exchange exchange() {
    DirectExchange exchange = new DirectExchange("bar");
    // exchange.setAdminsThatShouldDeclare(admin2());
    return exchange;
}

There are multiple RabbitMQ connections in the application (multiple RabbitAdmin instances)

Answer 1

All of them are going to declare this entity by default.

The logic in the RabbitAdmin is like this:

private <T extends Declarable> boolean declarableByMe(T dec) {
    return (dec.getDeclaringAdmins().isEmpty() && !this.explicitDeclarationsOnly) 
            || dec.getDeclaringAdmins().contains(this)
            || (this.beanName != null && dec.getDeclaringAdmins().contains(this.beanName));
}

See also that property description:

/**
 * Set to true to only declare {@link Declarable} beans that are explicitly configured
 * to be declared by this admin.
 * @param explicitDeclarationsOnly true to ignore beans with no admin declaration
 * configuration.
 * @since 2.1.9
 */
public void setExplicitDeclarationsOnly(boolean explicitDeclarationsOnly) {

Here is a doc on the matter: https://docs.spring.io/spring-amqp/docs/current/reference/html/#conditional-declaration