如何用spring重试包装耗尽重试时的异常

Question

上下文：

我正在使用spring-retry重试restTemplate调用。

restTemplate调用是从kafka侦听器调用的。kafka侦听器还被配置为在出错时重试（如果在过程中抛出任何异常，而不仅仅是restTemplate调用）。

目标：

当错误来自已耗尽的重试模板时，我想防止kafka重试。

实际行为：

当retryTemplate用尽所有重试时，将引发原始异常。从而阻止我识别RetryTemplate是否重试了该错误。

所需行为：

当retryTemplate用尽所有重试时，将原始异常包装在RetryEvertestedException中，这将允许我将其从kafka重试中列入黑名单。

问题：

我怎么能做这种事？

谢谢

编辑

RetryTemplate配置：

RetryTemplate retryTemplate = new RetryTemplate();

FixedBackOffPolicy backOffPolicy = new FixedBackOffPolicy();
backOffPolicy.setBackOffPeriod(1000);
retryTemplate.setBackOffPolicy(backOffPolicy);

Map<Class<? extends Throwable>, Boolean> retryableExceptions = new HashMap<>();
retryableExceptions.put(FunctionalException.class, false);
SimpleRetryPolicy retryPolicy = new SimpleRetryPolicy(3, retryableExceptions, true, true);
retryTemplate.setRetryPolicy(retryPolicy);

retryTemplate.setThrowLastExceptionOnExhausted(false);

Kafka错误处理程序

public class DefaultErrorHandler implements ErrorHandler {

@Override
public void handle(Exception thrownException, ConsumerRecord<?, ?> data) {
    Throwable exception = Optional.ofNullable(thrownException.getCause()).orElse(thrownException);

    // TODO if exception as been retried in a RetryTemplate, stop it to prevent rollback and send it to a DLQ
    // else rethrow exception, it will be rollback and handled by AfterRollbackProcessor to be retried
    throw new KafkaException("Could not handle exception", thrownException);
   }
}

听众Kafka：

@KafkaListener
public void onMessage(ConsumerRecord<String, String> record) {
    retryTemplate.execute((args) -> {
        throw new RuntimeException("Should be catched by ErrorHandler to prevent rollback");
    }
    throw new RuntimeException("Should be retried by afterRollbackProcessor");
}

Answer 1

只需使用SimpleRetryPolicy配置侦听器重试模板，该模板配置为将RetryEvertedException分类为不可重试。

确保将TraverSecauss属性设置为true，因为容器将所有侦听器异常包装在ListenerExecutionFailedException中。

/**
 * Create a {@link SimpleRetryPolicy} with the specified number of retry
 * attempts. If traverseCauses is true, the exception causes will be traversed until
 * a match is found. The default value indicates whether to retry or not for exceptions
 * (or super classes) 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 is this clause traversable
 * @param defaultValue the default action.
 */
public SimpleRetryPolicy(int maxAttempts, Map<Class<? extends Throwable>, Boolean> retryableExceptions,
        boolean traverseCauses, boolean defaultValue) {

编辑

使用

template.execute((args) -> {...}, (context) -> throw new Blah(context.getLastThrowable()));