Sentinel整合RestTemplate

resttemplate开启sentinel保护配置
properties 复制代码
```
resttemplate.sentinel.enabled=true
```

配置sentinel-dashboard地址

properties 复制代码

spring.cloud.sentinel.transport.dashboard=localhost:8858\
spring.cloud.sentinel.transport.dashboard.port=8739

实例化RestTemplate并加入@SentinelRestTemplate注解

java 复制代码

@Configuration
public class RestTemplateConfig {
    @Bean
    @LoadBalanced
    @SentinelRestTemplate(
            fallbackClass = ExceptionUtil.class,fallback = "fallBack",
            blockHandlerClass = ExceptionUtil.class, blockHandler = "handleBlock")
    public RestTemplate restTemplate() {
        return new RestTemplate();
    }

    public static class ExceptionUtil {
        public static ClientHttpResponse handleBlock(
                HttpRequest request, byte[] body, ClientHttpRequestExecution execution, BlockException be){
            RestResponse<Void> commonResult =  RestResponse.error("500","降级处理函数 block 。。。。。");
            return new SentinelClientHttpResponse(JSON.toJSONString(commonResult));
        }

        public static ClientHttpResponse fallBack(
                HttpRequest request, byte[] body, ClientHttpRequestExecution execution, BlockException be){
            RestResponse<Void> commonResult = RestResponse.error("500","异常处理函数 fallback 。。。。。");
            return new SentinelClientHttpResponse(JSON.toJSONString(commonResult));
        }
    }
}

编写测试代码,并使用postman访问对应的url

java 复制代码

@Slf4j
@RestController
@RequestMapping("/test")
public class TestController {
    @Autowired
    private RestTemplate restTemplate ;

    @GetMapping("/index")
    public RestResponse<String> index(){
        String url = "http://hello-nacos-client/hello/index" ;
        RestResponse<String> retValue = restTemplate.getForObject(url, RestResponse.class);
        log.info("ret value : {}", retValue);
        return retValue ;
    }
     
    @GetMapping("/exception")
    public Object exception(){
        String url = "http://hello-nacos-client/hello/exception" ;
        RestResponse<String> retValue = restTemplate.getForObject(url, RestResponse.class);
        log.info("ret value : {}", retValue);
        return retValue ;
    }
}

在dashboard上配置限流规则，再次通过postman调用url，能正常触发SentinelRestTemplate的blockHandler方法处理
在dashboard上配置熔断规则，再次通过postman调用url，能正常触发SentinelRestTemplate的fallBack方法处理