如何仅针对HTTP状态码500配置RetryTemplate？

Question

我正在使用spring-retry（带有Java 8 lambda）来重试失败的REST调用。我只想重试那些返回500错误的呼叫。但是我不能为此配置retrytemplate bean。当前，bean很简单，如下所示：

@Bean("restRetryTemplate")
public RetryTemplate retryTemplate() {

    Map<Class<? extends Throwable>, Boolean> retryableExceptions= Collections.singletonMap(HttpServerErrorException.class,
            Boolean.TRUE);
    SimpleRetryPolicy retryPolicy = new SimpleRetryPolicy(3, retryableExceptions);

    FixedBackOffPolicy backOffPolicy = new FixedBackOffPolicy();
    backOffPolicy.setBackOffPeriod(1500); // 1.5 seconds

    RetryTemplate template = new RetryTemplate();
    template.setRetryPolicy(retryPolicy);
    template.setBackOffPolicy(backOffPolicy);

    return template;
}

谁能帮我这个忙。提前致谢。

Answer 1

因此，我通过以下方式创建自定义RetryPolicy解决了我的问题：

RetryTemplate template = new RetryTemplate();
    template.setRetryPolicy(new InternalServerExceptionClassifierRetryPolicy());

实现如下：

public class InternalServerExceptionClassifierRetryPolicy extends ExceptionClassifierRetryPolicy {

    public InternalServerExceptionClassifierRetryPolicy() {

        final SimpleRetryPolicy simpleRetryPolicy = new SimpleRetryPolicy();
        simpleRetryPolicy.setMaxAttempts(3);

        this.setExceptionClassifier(new Classifier<Throwable, RetryPolicy>() {
            @Override
            public RetryPolicy classify(Throwable classifiable) {
                if (classifiable instanceof HttpServerErrorException) {
                    // For specifically 500 and 504
                    if (((HttpServerErrorException) classifiable).getStatusCode() == HttpStatus.INTERNAL_SERVER_ERROR
                            || ((HttpServerErrorException) classifiable)
                                    .getStatusCode() == HttpStatus.GATEWAY_TIMEOUT) {
                        return simpleRetryPolicy;
                    }
                    return new NeverRetryPolicy();
                }
                return new NeverRetryPolicy();
            }
        });
    }
}

希望这会对您有所帮助。