[Solved] When Feign’s call reports an error, the downgrade processing method, fallBackFactory

When Feign’s call reports an error, downgrade the fallBackFactory

Project Structure:

Code:

remoteCdsService

package com.gsafety.framework.api;

import com.alibaba.fastjson.JSONObject;
import com.gsafety.framework.api.constant.ServiceNameConstants;
import com.gsafety.framework.api.factory.RemoteRcsFallbackFactory;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestParam;

/**
 * @author wzx
 * @Description public resource service
 * @Date 2022/8/19 10:48
 */
@FeignClient(contextId = "remoteRcsService", value = ServiceNameConstants.RCS_SERVICE, fallbackFactory = RemoteRcsFallbackFactory.class)
public interface RemoteRcsService {<!-- -->

    /**
     * Get duplicate alert configuration
     * @return
     */
    @GetMapping("/config/v1/getRepeatWarnRuleInfo")
    public JSONObject getRepeatWarnRuleInfo();
}

remoteCdsFallbackFactory

package com.gsafety.framework.api.factory;

import com.alibaba.fastjson.JSONObject;
import com.gsafety.framework.api.RemoteRcsService;
import feign.hystrix.FallbackFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

/**
 * @author wzx
 * @Description public resource service downgrade processing
 * @Date 2022/8/19 10:53
 */
@Component
public class RemoteRcsFallbackFactory implements FallbackFactory<RemoteRcsService> {<!-- -->

    private static final Logger log = LoggerFactory.getLogger(RemoteRcsFallbackFactory.class);

    @Override
    public RemoteRcsService create(Throwable throwable) {<!-- -->
        log.error("rcs service failed:{}", throwable.getMessage());
        return new RemoteRcsService() {<!-- -->
            @Override
            public JSONObject getRepeatWarnRuleInfo() {<!-- -->
                return null;
            }

            @Override
            public JSONObject getDisposePlanListForOrganDispose(String warnType, String warnLevel, String zhId, String yhqk, Integer lc, String bkrs) {<!-- -->
                return null;
            }

            @Override
            public JSONObject queryListAddressBook() {<!-- -->
                return null;
            }

            @Override
            public JSONObject getAddressBooksByParentId(String itemParentId, String userId) {<!-- -->
                return null;
            }

            @Override
            public JSONObject queryAddressBookByIds(String ids) {<!-- -->
                return null;
            }

            @Override
            public JSONObject getParentSysDictDataDetail(String dictValue, String dictType) {<!-- -->
                return null;
            }

            @Override
            public JSONObject getDisposePlanListForWarnLevenUp(String warnType, String warnLevel, String zhId, String yhqk, Integer lc, String bkrs, String rswz, Integer rsmj) {<!-- -->
                return null;
            }

            @Override
            public JSONObject getImportantWarnNoticeList() {<!-- -->
                return null;
            }

            @Override
            public JSONObject getCarDutyRecord(String carNumber, String startTime, String endTime) {<!-- -->
                return null;
            }

            @Override
            public JSONObject getResImportantUnitByName(String name) {<!-- -->
                return null;
            }

            @Override
            public JSONObject addSysNoticeNew(String json) {<!-- -->
                return null;
            }
        };
    }
}

In this way, when an error is reported in the remoteCdsService interface, it will go to the create method in the RemoteCdsFallbackFactory for custom operations.

On my side, when an error is reported, the interface directly returns Null.

ContextId of Feign annotation:

@FeignClient(contextId = "remoteCdsService", value = ServiceNameConstants.CDS_SERVICE, fallbackFactory = RemoteCdsFallbackFactory.class)

• contextId: used to uniquely identify the scenario when there are multiple FeignClient interfaces in a microservice calling the same service provider (if this property value is not provided, it will fail to start when the program starts, and the following information will be prompted

• APPLICATION FAILED TO START

  Description:

  The bean ‘service-provider8000.FeignClientSpecification’ could not be registered. A bean with that name has already been defined and overriding is disabled.

  Action:

n service-provider8000.FeignClientSpecification’ could not be registered. A bean with that name has already been defined and overriding is disabled.

Action:

Consider renaming one of the beans or enabling overriding by setting spring.main.allow-bean-definition-overriding=true