如何使用SimpleRetryPolicy从Spring AMQP重试策略中排除特定异常？

Question

我的 Spring AMQP 应用程序中有一个 RabbitListener，并且我正在使用自定义 RabbitListenerFactory 和配置用于消息重试的 SimpleRetryPolicy。但是，我想排除某些例外情况的重试。目前，我的配置如下：

@Bean
fun retryPolicy(): SimpleRetryPolicy {
    val exceptions = mutableMapOf<Class<out Throwable>, Boolean>(
        ValidationException::class.java to false,
        IllegalArgumentException::class.java to false,
        EntityNotFoundException::class.java to false,
    )
    return SimpleRetryPolicy(6, exceptions, true)
}

@Bean
fun retryInterceptor(customMessageRecoverer: CustomMessageRecoverer): RetryOperationsInterceptor? {
    return RetryInterceptorBuilder.stateless().retryPolicy(retryPolicy())
        .backOffOptions(1000, 2.0, 5000)
        .recoverer(customMessageRecoverer)
        .build()
}

@Bean
fun myFactory(
    configurer: SimpleRabbitListenerContainerFactoryConfigurer,
    connectionFactory: ConnectionFactory,
    customsMessageRecoverer: CustomMessageRecoverer,
): SimpleRabbitListenerContainerFactory {
    val factory = SimpleRabbitListenerContainerFactory()
    configurer.configure(factory, connectionFactory)
    factory.setAdviceChain(workMessagesRetryInterceptor(customsMessageRecoverer))
    return factory;
}

但是，我注意到使用此配置，根本不会执行重试，即使对于不在排除列表中的异常也是如此。如何修改此配置以既排除特定异常（例如 AuthoraizationException 或 IllegalArgumentException）重试，又确保其他异常仍根据重试策略重试？ 任何代码示例将不胜感激。 预先感谢！

Answer 1

请参阅另一个构造函数

SimpleRetryPolicy

：

/**
 * Create a {@link SimpleRetryPolicy} with the specified number of retry attempts. If
 * traverseCauses is true, the exception causes will be traversed until a match or the
 * root cause is found. The default value indicates whether to retry or not for
 * exceptions (or super classes thereof) that are not found in the map.
 * @param maxAttempts the maximum number of attempts
 * @param retryableExceptions the map of exceptions that are retryable based on the
 * map value (true/false).
 * @param traverseCauses true to traverse the exception cause chain until a classified
 * exception is found or the root cause is reached.
 * @param defaultValue the default action.
 */
public SimpleRetryPolicy(int maxAttempts, Map<Class<? extends Throwable>, Boolean> retryableExceptions,
        boolean traverseCauses, boolean defaultValue) {

在您的情况下，

defaultValue

设置为

false

，含义是不重试其余未映射的异常。听起来您需要完全相反：重试所有异常并针对映射执行特定操作。

Answer 2

其他选项是覆盖SimpleRetryPolicy

public class IgnoreFatalErrorSimpleRetryPolicy extends SimpleRetryPolicy {
  private static final FatalExceptionStrategy exceptionStrategy =
      new ConditionalRejectingErrorHandler.DefaultExceptionStrategy();

  public IgnoreFatalErrorSimpleRetryPolicy(int maxAttempts) {
    super(maxAttempts);
  }

  @Override
  public boolean canRetry(RetryContext context) {
    return !exceptionStrategy.isFatal(context.getLastThrowable()) && super.canRetry(context);
  }

}