java - 使用重试模板执行自定义重试策略

Question

我有一个自定义重试策略，旨在每当应用程序收到非 404 的 http 状态代码时执行重试。我还创建了一个重试模板。我陷入了如何使用重试模板执行自定义重试策略的困境。对此以及如何测试我的结果的任何帮助都会非常好。我已包含重试模板和自定义重试策略的代码。

public RetryTemplate retryTemplate() {
        RetryTemplate retryTemplate = new RetryTemplate();

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

        NeverRetryPolicy doNotRetry = new NeverRetryPolicy();
        SimpleRetryPolicy retryPolicy = new SimpleRetryPolicy();
        retryPolicy.setMaxAttempts(maxAttempts);
        retryTemplate.setRetryPolicy(retryPolicy);

        return retryTemplate;
    }






public class HttpFailedConnectionRetryPolicy extends ExceptionClassifierRetryPolicy {

@Value("${maxAttempts:-1}")
private String maxAttempts;

public void HttpFailedConnectionRetryPolicy() {
    this.setExceptionClassifier(new Classifier<Throwable, RetryPolicy>() {
        @Override
        public RetryPolicy classify(Throwable classifiable) {
            Throwable exceptionCause = classifiable.getCause();
            if (exceptionCause instanceof HttpStatusCodeException) {
                int statusCode = ((HttpStatusCodeException) classifiable.getCause()).getStatusCode().value();
                return handleHttpErrorCode(statusCode);
            }
            return simpleRetryPolicy();
        }
    });
}

public void setMaxAttempts(String maxAttempts) {
    this.maxAttempts = maxAttempts;
}

private RetryPolicy handleHttpErrorCode(int statusCode) {
    RetryPolicy retryPolicy = null;
    switch (statusCode) {
        case 404:
            retryPolicy = doNotRetry();
            break;
        default:
            retryPolicy = simpleRetryPolicy();
            break;
    }
    return retryPolicy;
}

private RetryPolicy doNotRetry() {

    return new NeverRetryPolicy();
}

private RetryPolicy simpleRetryPolicy() {
    final SimpleRetryPolicy simpleRetryPolicy = new SimpleRetryPolicy();
    simpleRetryPolicy.setMaxAttempts(Integer.valueOf(maxAttempts));
    return simpleRetryPolicy;
}

}

Answer 1

只需将重试策略的实例(而不是 SimpleRetryPolicy)注入(inject)到模板中。

要进行测试，您可以将 RetryListener 添加到测试用例中的模板。