问题

通过@SentinelResource设置定制的fallback、blockhandler方法。

@GetMapping(value = "/test")
    @SentinelResource(value = "test", fallbackClass = ControllerFallback.class, fallback = "handlerFallback", // fallback只负责业务异常
            blockHandlerClass = ControllerBlockHandler.class, blockHandler = "handlerException1", // blockHandler只负责sentinel控制台配置违规
            exceptionsToIgnore = {IllegalArgumentException.class})
    public Result<String> test(@RequestParam(value = "id") String id) throws InterruptedException {
        log.info("有用户访问 test");
        int i = 10 / 0;
//        TimeUnit.SECONDS.sleep(http://img.itvip666.com/group1/M00/00/09/wKgB_F-eNtOAVp9cAABTsoCoCHE995.png);
        return new Result<>().ok("测试通过啦");
    }

但是我们也不可能每个限制的方法上面，都要去设置@SentinelResource；这样代码太冗余了。

全局统一处理

定义一个类实现 BlockExceptionHandler 接口

注意

• Alibaba v2.1.0和Alibaba v2.2.0不一样，接口发生了变化
• 下面的代码是针对 spring cloud Alibaba v2.2.0

/**
 * 定义BlockExceptionHandler接口限流处理逻辑
 */
public class CustomBlockHandler implements BlockExceptionHandler {
    @Override
    public void handle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, BlockException e) throws Exception {
        Result<String> result = new Result<String>();
        // 不通的异常可以做不同的事情
        // 如果是限流异常
        if (e instanceof FlowException) {
            result = new Result<String>().error("限流了");
        } else if (e instanceof DegradeException) {
            result = new Result<String>().error("降级异常");
        } else if (e instanceof ParamFlowException) {
            result = new Result<String>().error("热点参数限流");
        } else if (e instanceof SystemBlockException) {
            result = new Result<String>().error("系统异常");
        } else if (e instanceof AuthorityException) {
            result = new Result<String>().error("授权异常");
        }
        httpServletResponse.setStatus(500);
        httpServletResponse.setCharacterEncoding("utf-8");
        httpServletResponse.setHeader("Content-Type","application/json;charset=UTF-8");
        httpServletResponse.setContentType("application/json;charset=utf-8");
        new ObjectMapper()
                .writeValue(httpServletResponse.getWriter(),result);
    }
}

• CustomBlockHandlerConfig，将自定义的降级处理类加入到spring容器中

@Configuration
public class CustomBlockHandlerConfig {
    @Bean
    public BlockExceptionHandler getBlockExceptionHandler() {
        return new CustomBlockHandler();
    }
}

测试

我设置的是流控，当快速点击的时候就会发生限流异常