Spring重试：NeverRetryLogic与ExceptionClassifierRetryPolicy不一样

Question

我在一个重试场景中工作（与http出站网关相关）。重试逻辑工作得很好，但是我的不重试逻辑看起来有一个bug。

也就是说，我期望的是，当我第一次配置endpoint以获得HTTP400状态时，永远不会重试，但看起来这不起作用。

我对永不重试场景的逻辑是这样的：

   <int-http:outbound-gateway
            header-mapper="httpHeaderMapper"
            request-channel="some_request_channel"
            url-expression="'http://some_url"
            http-method="POST"
            expected-response-type="java.lang.String"
            charset="UTF-8"
            reply-timeout="${com.property.value.from.db.for.time.out:5000}"
            reply-channel="some_reply_channel">

            <int-http:request-handler-advice-chain>
                        <bean class="org.springframework.integration.handler.advice.RequestHandlerRetryAdvice">
                            <property name="recoveryCallback">
                                <bean class="org.springframework.integration.handler.advice.ErrorMessageSendingRecoverer">
                                    <constructor-arg ref="errorChannel" />
                                </bean>
                            </property>
                            <property name="retryTemplate" ref="retryTemplate" />
                        </bean>
            </int-http:request-handler-advice-chain>

    </int-http:outbound-gateway>


    <bean id="retryTemplate" class="org.springframework.retry.support.RetryTemplate">
        <property name="retryPolicy">
            <bean class="com.whatever.CustomRetryPolicy">
                <property name="maxAttempts" value="${com.property.value.from.db.for.retry.MaxAttemps:5}" />
            </bean>
        </property>
        <property name="backOffPolicy">
            <bean class="org.springframework.retry.backoff.ExponentialBackOffPolicy">
                <property name="initialInterval" value="${com.property.value.from.db.for.backoffpolicy.initialInterval:1000}" />
                <property name="multiplier" value="${com.property.value.from.db.for.backoffpolicy.initialInterval:6}" />
            </bean>
        </property>
    </bean> 

CustomRetryPolicy如下所示：

public class CustomRetryPolicy extends ExceptionClassifierRetryPolicy {

    private String maxAttempts;

    @PostConstruct
    public void init() {

        final RetryPolicy defaultRetry = defaultRetryPolicy();
        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();
                    handleHttpErrorCode(statusCode);
                }
                return defaultRetry;
            }
        });
    }

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


    private RetryPolicy handleHttpErrorCode(int statusCode) {
        RetryPolicy retryPolicy = null;
        switch(statusCode) {
        case 404 :
        case 500 :
        case 503 :
        case 504 :
            retryPolicy = defaultRetryPolicy();
            break;
        default :
            retryPolicy = neverRetry();
            break;
        }

        return retryPolicy;
    }

    private RetryPolicy neverRetry() {
        return new NeverRetryPolicy();
    }

    private RetryPolicy defaultRetryPolicy() {
        final SimpleRetryPolicy simpleRetryPolicy = new SimpleRetryPolicy();
        simpleRetryPolicy.setMaxAttempts(5);
        return simpleRetryPolicy;
    }

}

Answer 1

您总是返回默认策略；这里似乎需要返回...

return handleHttpErrorCode(statusCode);

顺便说一句，最好创建一次策略，而不是每次创建一个新的策略。