Spring -@Recover - 找不到恢复方法

Question

我有一个 Spring 项目，在类中包含 Retryable 和 Recover 方法。 重试 2 次后，代码无法命中 Recover 方法块，错误为

Cannot locate recovery method; nested exception is org.springframework.web.client.ResourceAccessException: I/O error on POST request for "http://localhost:8081/api/start": Connection refused; nested exception is java.net.ConnectException: Connection refused

Retryable方法附属于AOP。

代码可在 Github Repo 中找到：https://github.com/Nikhilgupta1891/RetryRecover

在存储库中，以下是相关的类名称：

1. AOP：ApcAspect.java
2. 调度程序（入口点）：ScheduledClass.java
3. 服务类未运行恢复：ClassTwo.java#L37

附上ClassTwo的代码以供快速参考：

package com.abc.pbm.racassignmentpoll.services;

import lombok.extern.slf4j.Slf4j;
import org.springframework.http.ResponseEntity;
import org.springframework.retry.annotation.Backoff;
import org.springframework.retry.annotation.Recover;
import org.springframework.retry.annotation.Retryable;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;

import java.util.Collections;
import java.util.HashMap;
import java.util.Map;

@Slf4j
@Service
public class ClassTwo {
    private final RestTemplate restTemplate = new RestTemplate();
    private final String crimApiBaseUrl = "http://localhost:8081/api/";

    @Retryable(maxAttemptsExpression = "2", backoff = @Backoff(delayExpression = "5000"))
    public ResponseEntity startSecondMethod(String invEligDt, String runType) {
        Map<String, Object> reqBody = new HashMap<>();
        reqBody.put("INV_ELIG_DT", invEligDt);
        reqBody.put("RUNTYPE", runType);

        ResponseEntity responseEntity = restTemplate.postForEntity(crimApiBaseUrl + "start",
                reqBody,
                null,
                Collections.EMPTY_MAP);
        return responseEntity;
    }

    @Recover
    public void recover(Exception error, String invEligDt, String runType){
        // Some action.
        log.info("INside recovery");
    }
}

Answer 1

两个方法的返回类型以及Retryable和Recovery方法的输入参数应该相同。

Answer 2

@Retryable 和 @Recover 方法都应该具有相同的返回类型。以上面的例子来说，应该将@Recover方法更改为：

@Recover
public ResponseEntity recover(Exception error, String invEligDt, String runType){
    // Some action.
    log.info("Inside recover method");
   return null;
}

这与@Retryable方法的返回类型匹配

@Retryable(maxAttemptsExpression = "2", backoff = @Backoff(delayExpression = "5000"))
public ResponseEntity startSecondMethod(String invEligDt, String runType) {
    Map<String, Object> reqBody = new HashMap<>();
    reqBody.put("INV_ELIG_DT", invEligDt);
    reqBody.put("RUNTYPE", runType);

    ResponseEntity responseEntity = restTemplate.postForEntity(crimApiBaseUrl + "start",
            reqBody,
            null,
            Collections.EMPTY_MAP);
    return responseEntity;
}