AlibabaCloud版本升级-⾃定义降级异常不向下兼容的坑

默认降级返回数据问题

• 限流和熔断返回的数据有问题
• 微服务交互基本都是json格式，如果让⾃定义异常信息

AlibabCloud版本升级，不兼容问题

• v2.1.0到v2.2.0后，Sentinel⾥⾯依赖进⾏了改动，且不向下兼容

⾃定义降级返回数据

• 【旧版】实现UrlBlockHandler并且重写blocked⽅法

@Component
public class XdclassUrlBlockHandler
implements UrlBlockHandler {
 @Override
 public void blocked(HttpServletRequest
httpServletRequest, HttpServletResponse
httpServletResponse, BlockException e) throws
IOException {
 //降级业务处理
 }
}

• 【新版】实现BlockExceptionHandler并且重写handle⽅法

public class XdclassUrlBlockHandler
implements BlockExceptionHandler {
 
 @Override
 public void handle(HttpServletRequest
httpServletRequest, HttpServletResponse
httpServletResponse, BlockException e) throws
Exception {
 //降级业务处理
 }
}

新版Sentinel⾃定义降级异常数据开发实战

异常种类

• FlowException //限流异常
• DegradeException //降级异常
• ParamFlowException //参数限流异常
• SystemBlockException //系统负载异常
• AuthorityException //授权异常

【新版】实现BlockExceptionHandler并且重写handle⽅法

@Component
public class AlibabaUrlBlockHandler implements BlockExceptionHandler {
    @Override
    public void handle(HttpServletRequest request, HttpServletResponse response, BlockException e) throws Exception {
        Map result = new HashMap<>();
        if (e instanceof FlowException){
            result.put("code",-1);
            result.put("message","限流异常！");
        } else if (e instanceof DegradeException){
            result.put("code",-2);
            result.put("message","降级异常！");
        } else if (e instanceof ParamFlowException){
            result.put("code",-3);
            result.put("message","热点异常！");
        } else if (e instanceof SystemBlockException){
            result.put("code",-4);
            result.put("message","系统规则异常！");
        } else if (e instanceof AuthorityException){
            result.put("code",-5);
            result.put("message","认证异常！");
        }
        //设置返回数据
        response.setStatus(200);
        response.setHeader("content-type","application/json;charset=UTF-8");
        response.getWriter().write(JSON.toJSONString(result));
    }
}

降级测试

流控测试

新版Sentinel整合OpenFeign配置实战

• 加⼊依赖

       com.alibaba.cloud
       spring-cloud-starter-alibaba-sentinel

• 开启Feign对Sentinel的⽀持

#开启Feign对Sentinel的支持
feign:
  sentinel:
    enabled: true

• 创建容错类, 实现对应的服务接⼝, 记得加注解

@Service
public class VideoServiceFallback implements VideoService {
    @Override
    public Video findById(int videoId) {
        Video video = new Video();
        video.setTitle("系统默认数据！");
        return video;
    }

    @Override
    public int save(Video video) {
        return 0;
    }
}

• 配置feign容错类

@FeignClient(name = "alibaba-video",fallback = VideoServiceFallback.class)

• 测试

参考源码：alibaba-cloud: alibaba-cloud学习

参考原文：cyz