java - Spring Boot定义多个交换

Question

这个问题已经有答案了:

Required Multiple beans of same type in Spring (3 个回答)

已关闭 4 年前。

我需要声明多个扇出交换

@SpringBootApplication
public class Application {
  @Bean
  FanoutExchange exchange1() {
    return new FanoutExchange(exchangeName1, true, false);
  }

  @Bean
  FanoutExchange exchange2() {
    return new FanoutExchange(exchangeName2, true, false);
  }

  ....
  ....
}

一旦我添加 exchange2 的代码我收到错误:

---

APPLICATION FAILED TO START

---

Description:

Parameter 1 of method binding in com.Application required a single bean, but 2 were found: - exchange1: defined by method 'exchange1' in com.Application - exchange2: defined by method 'exchange2' in com.Application

Action:

Consider marking one of the beans as @Primary, updating the consumer to accept multiple beans, or using @Qualifier to identify the bean that should be consumed

Answer 1

异常告诉你解决办法:

1. bean 上的用户限定符
2. 使用@Primary定义2个bean中哪一个是主要的

您的代码应该如下所示

@SpringBootApplication
public class Application {

    @Bean
    @Qualifier("exchange1")
    @Primary
    FanoutExchange exchange1() {
       return new FanoutExchange(exchangeName1, true, false);
    }

    @Bean
    @Qualifier("exchange2")
    FanoutExchange exchange2() {
       return new FanoutExchange(exchangeName2, true, false);
    }
 }