sentinel 之 SentinelRestTemplate

SentinelRestTemplate用於 sentinel 集成 RestTemplate
添加在 RestTemplate 主鍵上，全局的限流容錯處理，優先級低於局部限流容錯注解 @SentinelResource

例如：

package com.example;

import com.alibaba.cloud.sentinel.annotation.SentinelRestTemplate;
import com.example.exception.ExceptionUtil;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;

@SpringBootApplication
public class OrderServiceRestApplication {

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

    public static void main(String[] args) {
        SpringApplication.run(OrderServiceRestApplication.class, args);
    }

}

blockHandler 　　　限流策略 　（方法名，方法必須是靜態的）
blockHandlerClass 限流方法類
fallback　　　　　　熔斷降級策略（方法名，方法必須是靜態的）
fallbackClass 　　 熔斷降級類
例如：

package com.example.exception;

import com.alibaba.cloud.sentinel.rest.SentinelClientHttpResponse;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.alibaba.fastjson.JSON;
import com.example.pojo.Product;
import org.springframework.http.HttpRequest;
import org.springframework.http.client.ClientHttpRequestExecution;
import org.springframework.http.client.ClientHttpResponse;

public class ExceptionUtil {

    // 服務流量控制處理
    public static ClientHttpResponse handleException(HttpRequest request,
                                                     byte[] body,
                                                     ClientHttpRequestExecution execution,
                                                     BlockException exception) {
        exception.printStackTrace();
        return new SentinelClientHttpResponse(
                JSON.toJSONString(new Product(1, "服務流量控制處理-托底數據", 2, 2666D)));
    }

    // 服務熔斷降級處理
    public static ClientHttpResponse fallback(HttpRequest request,
                                                    byte[] body,
                                                    ClientHttpRequestExecution execution,
                                                    BlockException exception) {
        exception.printStackTrace();
        return new SentinelClientHttpResponse(
                JSON.toJSONString(new Product(1, "服務熔斷降級處理-托底數據", 2, 2666D)));
    }

}