-------------------------||||||| ribbon |||||||-------------------------
//-----------------------------------------------------------------------------------------------------------provider 服务提供方
pom核心依赖
<dependencies>
<!--SpringCloud ailibaba nacos -->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</artifactId>
</dependency>
</dependencies>
yml 比较常规的配置
server:
port: 9003
spring:
application:
name: nacos-payment-provider
# nacos配置
cloud:
nacos:
discovery:
server-addr: localhost:8848 #配置Nacos地址
management:
endpoints:
web:
exposure:
include: '*'
启动类注解不能少@EnableDiscoveryClient
测试地址http://localhost:9003/paymentSQL/1
//-----------------------------------------------------------------------------------------------------------consumer消费者端
core dependency
<!--SpringCloud ailibaba nacos -->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>
<!--SpringCloud ailibaba sentinel ( 需要使用sentinel对消费者侧进行熔断,降级,限流)-->
<dependency>
<groupId>com.alibaba.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
</dependency>
yml
server:
port: 84
spring:
application:
name: nacos-order-consumer
cloud:
#nacos 配置
nacos:
discovery:
server-addr: localhost:8848
#sentinel配置
sentinel:
transport:
#配置Sentinel dashboard地址
dashboard: localhost:8080
#默认8719端口,假如被占用会自动从8719开始依次+1扫描,直至找到未被占用的端口
port: 8719
#消费者将要去访问的微服务名称(注册成功进nacos的微服务提供者)
service-url:
nacos-user-service: http://nacos-payment-provider
启动类注解@EnableDiscoveryClient 表示要注册中心发现
resttemplate bean
@Configuration
public class ApplicationContextConfig
{
@Bean
@LoadBalanced
public RestTemplate getRestTemplate()
{
return new RestTemplate();
}
}
把fallback 和 blocHandler都配上 双剑合璧 服务更稳定
package com.atguigu.springcloud.alibaba.controller;
import com.alibaba.csp.sentinel.annotation.SentinelResource;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.atguigu.springcloud.entities.CommonResult;
import com.atguigu.springcloud.entities.Payment;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
@RestController
@Slf4j
public class CircleBreakerController
{
public static final String SERVICE_URL = "http://nacos-payment-provider";
@Resource
private RestTemplate restTemplate;
@RequestMapping("/consumer/fallback/{id}")
// value 资源id fallback 运行时异常兜底方法名 blockHandler 自定义的降级兜底方法名
@SentinelResource(value = "fallback",fallback = "handlerFallback",blockHandler = "blockHandler")
public CommonResult<Payment> fallback(@PathVariable Long id)
{
CommonResult<Payment> result = restTemplate.getForObject(SERVICE_URL + "/paymentSQL/"+id,CommonResult.class,id);
if (id == 4) {
throw new IllegalArgumentException ("非法参数异常....");
}else if (result.getData() == null) {
throw new NullPointerException ("NullPointerException,该ID没有对应记录");
}
return result;
}
// fallback handler
public CommonResult handlerFallback(@PathVariable Long id,Throwable e) {
Payment payment = new Payment(id,"null");
return new CommonResult<>(444,"fallback,无此流水,exception "+e.getMessage(),payment);
}
// blockHandler
public CommonResult blockHandler(@PathVariable Long id,BlockException blockException) {
Payment payment = new Payment(id,"null");
return new CommonResult<>(445,"blockHandler-sentinel限流,无此流水: blockException "+blockException.getMessage(),payment);
}
}
若 blockHandler 和 fallback 都进行了配置,则被限流降级而抛出 BlockException 时只会进入 blockHandler 处理逻辑。
-------------------------||||||| openfeign + fallback (服务提供者宕机或者其他异常时,消费者将进入降级) |||||||-------------------------
既然需要使用openfeign,就要导入openfeign的依赖
<!--SpringCloud openfeign -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>
然后对yaml进行配置,添加下面的配置 ,激活sentinel对feign的支持
# 激活Sentinel对Feign的支持
feign:
sentinel:
enabled: true
接口类 服务降级关键注解 @FeignClient
// PaymentFallbackService为自定义降级处理类 value为服务提供者的名称
@FeignClient(value = "nacos-payment-provider",fallback = PaymentFallbackService.class)//调用中关闭9003服务提供者
public interface PaymentService
{
// 路径请与服务提供者的路径保持一致
@GetMapping(value = "/paymentSQL/{id}")
public CommonResult<Payment> paymentSQL(@PathVariable("id") Long id);
}
接口实现类
@Component
public class PaymentFallbackService implements PaymentService
{
@Override
public CommonResult<Payment> paymentSQL(Long id)
{
return new CommonResult<>(444,"服务降级返回,没有该流水信息",new Payment(id, "errorSerial......"));
}
}
启动类
@EnableDiscoveryClient
@SpringBootApplication
@EnableFeignClients // 启动类新增注解,启动对feign的支持
public class OrderNacosMain84
{
public static void main(String[] args) {
SpringApplication.run(OrderNacosMain84.class, args);
}
}
此时即可输入http://localhost:84/consumer/paymentSQL/1(是你自己的地址) 进行测试
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