如果不调用“setAdminsThatShouldDeclare”，则默认选择哪个 RabbitAdmin？

【问题标题】：Which RabbitAdmin is selected by default if "setAdminsThatShouldDeclare" is not called?如果不调用“setAdminsThatShouldDeclare”，则默认选择哪个 RabbitAdmin？
【发布时间】：2021-10-07 08:34:29
【问题描述】：

我想声明 Queue 和 Exchange，如果我不在 Queue 或 Exchange 上调用 setAdminsThatShouldDeclare，则会选择哪个 RabbitAdmin 实例：

@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;
}

应用中有多个RabbitMQ连接（多个RabbitAdmin实例）

【问题讨论】：

标签： spring-boot rabbitmq spring-amqp

【解决方案1】：

他们都将默认声明这个实体。

RabbitAdmin中的逻辑是这样的：

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));
}

另请参阅该属性说明：

/**
 * 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) {

这是一个关于此事的文档：https://docs.spring.io/spring-amqp/docs/current/reference/html/#conditional-declaration

【讨论】：