在应用程序启动时不创建Spring AMQP-RabbitMQ连接

Question

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
    <version>2.3.5.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.springframework.amqp</groupId>
    <artifactId>spring-rabbit</artifactId>
    <version>2.2.12.RELEASE</version>
</dependency>

@Configuration
public class RabbitConfiguration {

    @Bean
    public ConnectionFactory connectionFactory() {
        CachingConnectionFactory connectionFactory = new CachingConnectionFactory("myhost", 5672);
        connectionFactory.setUsername("example_name");
        connectionFactory.setPassword("example_pass");
        return connectionFactory;
    }

    @Bean
    public AmqpAdmin rabbitAdmin(ConnectionFactory connectionFactory) {
        return new RabbitAdmin(connectionFactory);
    }

    @Bean
    public Queue declareQueue() {
        return new Queue("test_queue", true, false, false);
    }

    @Bean
    public DirectExchange declareDirectExchange() {
        return new DirectExchange("test_direct_exchange", true, false);
    }

    @Bean
    public Declarables declareBindings() {

        return new Declarables(
            new Binding("test_queue", DestinationType.QUEUE, "test_direct_exchange", "test_routing_key", null)
        );
    }
}

Answer 1

如果您想在应用程序启动期间强制声明，并且没有任何消费者，您可以将actuator starter添加到类路径中，或者简单地自己创建共享连接。

@Bean
ApplicationRunner runner(ConnectionFactory cf) {
    return args -> cf.createConnection().close();
}

这不会关闭连接；如果要这样做，请调用cf.resetconnection()。

如果您希望在代理关闭时启动应用程序，请执行以下操作。

@Bean
ApplicationRunner runner(ConnectionFactory cf) {
    return args -> {
        boolean open = false;
        while(!open) {
            try {
                cf.createConnection().close();
                open = true;
            }
            catch (Exception e) {
                Thread.sleep(5000);
            }
        }
    };
}