利用断路器状态统计sentinel熔断次数

最近项目需要sentinel熔断时记录熔断的次数，在经过一阵搜索后决定利用断路器的状态变化来实现此功能
然而，遇到了这样的一个情况，断路器的状态在第一次熔断时正常从close–>open，但在后续（熔断时间内blocked或者熔断结束后重新开启断路器）断路器的状态变化均为half open–>open,导致无法区分究竟是熔断时间内还是再次被熔断了，因此使用了一个flag来做标记实现了功能。

本方法利用了断路器的状态统计熔断次数，代码修改自chatgpt

代码如下：

/*** @ClassName: SentinelBlockHandler* @Description: sentinel统一异常处理* @author: liuzijian @ haiyisoft* @Date: 2023/11/7 11:54* @version: 1.0**/
@Component
@Slf4j
public class SentinelBlockHandler implements BlockExceptionHandler {private boolean flag = false;@Resourceprivate ServerDegradeLogsRepository serverDegradeLogsRepository;@Value("${server.port}")private Integer serverPort;private SentinelBlockHandler() {// 私有构造方法，防止外部实例化}public static SentinelBlockHandler getInstance() {return SingletonHolder.INSTANCE;}private static class SingletonHolder {private static final SentinelBlockHandler INSTANCE = new SentinelBlockHandler();}static {registerStateChangeObserver();}private static void registerStateChangeObserver() {EventObserverRegistry.getInstance().addStateChangeObserver("logging",(prevState, newState, rule, snapshotValue) -> {List<CircuitBreakerStateChangeObserver> observers = EventObserverRegistry.getInstance().getStateChangeObservers();if (newState == CircuitBreaker.State.OPEN) {getInstance().flag = true;System.err.println(String.format("===> resource: %s, %s -> OPEN at %d, snapshotValue=%.2f",rule.getResource(), prevState.name(), TimeUtil.currentTimeMillis(), snapshotValue));} else {System.err.println(String.format("===> resource: %s, %s -> %s at %d",rule.getResource(), prevState.name(), newState.name(), TimeUtil.currentTimeMillis()));}});}@Overridepublic void handle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, BlockException e) throws Exception {/*** 请求被限流了*/if (e instanceof FlowException){httpServletResponse.setStatus(429);ResponseService.httpResponse(httpServletResponse, ResponseStatus.SENTINEL_FLOW_ERROR);log.error("请求被限流了:{}",e.getMessage());}/*** 请求被熔断降级了*/else if (e instanceof DegradeException) {System.out.println("进入熔断异常");if (getInstance().flag){InetAddress addr = InetAddress.getLocalHost();String degradeText = "请求被熔断降级了:{" + e.getMessage() + "}";ServerDegradeLogs serverDegradeLogs = new ServerDegradeLogs(addr.getHostAddress(), this.serverPort, degradeText);serverDegradeLogsRepository.save(serverDegradeLogs);getInstance().flag = false;}httpServletResponse.setStatus(429);ResponseService.httpResponse(httpServletResponse, ResponseStatus.SENTINEL_DEGRADE_ERROR);log.error("请求被熔断降级了:{}",e.getMessage());}/*** 热点被限流了*/else if (e instanceof ParamFlowException) {httpServletResponse.setStatus(429);ResponseService.httpResponse(httpServletResponse, ResponseStatus.SENTINEL_PARAM_FLOW_ERROR);log.error("热点被限流了:{}",e.getMessage());}/*** 请求没有权限*/else if (e instanceof AuthorityException) {httpServletResponse.setStatus(401);ResponseService.httpResponse(httpServletResponse, ResponseStatus.UNAUTHORIZED);log.error("请求没有权限:{}",e.getMessage());}}
}