在创建 bean Spring 引导时尝试传递字符串参数

Question

我有一个如下定义的bean..上下文是自动装配的..

@Autowired
private ApplicationContext context;
 ... 
RabbitQueue queue = (RabbitQueue) context.getBean("rabbitQueue");
QueueName queueNameTest = (QueueName) context.getBean("QueueName", "audittesting");

此 queueNameTest 将作为参数传递给另一个 bean 创建。

Queue q1= queue.createQueue(queueNameTest);

这个 createQueue bean 定义就像..

@Bean
public Queue createQueue(QueueName queueName) {
    String strQueueName = queueName.getQueueName();
    logger.info("Created rabbitmq queue {}", strQueueName);
    return QueueBuilder
             .durable(strQueueName)
             .withArguments(deadLetterArgs(AuditRabbitMQConstants.DL_ROUTING_KEY))
             .build();
    }

现在在 QueueName class 我有..

@Component
public class QueueName {
    private String arg;

    public QueueName(String arg) {
        this.arg = arg;
    }
    public String getQueueName()
    {
        return arg;
    }
}

当我试图跑步时..我得到

n***************************nAPPLICATION FAILED TO STARTn***************************nDescription:nParameter 0 of constructor in com.rabbitmq.QueueName required a bean of type 'java.lang.String' that could not be found.nAction:nConsider defining a bean of type 'java.lang.String' in your configuration.n"}

基本上我需要在运行时动态地将参数传递给 createQueue() .. 我该如何实现呢？

Answer 1

您需要以编程方式创建一个 bean

尝试以下

ConfigurableApplicationContext configContext = (ConfigurableApplicationContext)context;
SingletonBeanRegistry beanRegistry = configContext.getBeanFactory();

Queue myQueue = createQueue("myString");
beanRegistry.registerSingleton("queue", myqueue);

//remove @bean from here it will not be created automatically
//keep the method to create bean programmaticaly
public Queue createQueue(QueueName queueName) {
    String strQueueName = queueName.getQueueName();
    logger.info("Created rabbitmq queue {}", strQueueName);
    return QueueBuilder.durable(strQueueName)
            .withArguments(deadLetterArgs(AuditRabbitMQConstants.DL_ROUTING_KEY))
            .build();
}

//Remove @Component from here it will not be created automatically
public class QueueName {

如果你有某个地方

@Autowired
Queue queue

然后做

@Autowired
@Lazy
Queue queue

因为它将被延迟初始化。

编辑：根据这里询问的评论是如何动态注册原型bean

如果您使用的是 Spring 5 或更高版本，您可以使用GenericApplicationContext

public yourClass {

   @Autowired
   private GenericApplicationContext context;

   public Queue registerQueue(QueueName queueName) {
    String strQueueName = queueName.getQueueName();
    logger.info("Created rabbitmq queue {}", strQueueName);
    
     context.registerBean(queueName, Queue.class, ()-> 
               QueueBuilder.durable(strQueueName) 
            .withArguments(deadLetterArgs(AuditRabbitMQConstants.DL_ROUTING_KEY))
            .build() );
    }