- SpringCloud之Hystrix及声明式服务调用
- 一、项目准备
- 1.pom文件（先集成在服务提供方）
- 2.编写服务提供方启动类
- 3.创建服务提供方测试类controller
- 4.创建服务消费方进行测试
- 1.pom文件
- 2.yml文件
- 3.启动类
- 4.使用@FeignClient进行远程调用服务提供方
- 5.创建消费方测试类controller
- 6. **注：yml文件未设置feign超时间设置报错如下**
一、项目准备 1.pom文件（先集成在服务提供方）
2.编写服务提供方启动类4.0.0 com.yun cloud-provider 1.0-SNAPSHOT cloud-provider http://www.example.com UTF-8 1.7 1.7 junit junit 4.11 test org.springframework.cloud spring-cloud-starter-netflix-hystrix org.springframework.cloud spring-cloud-starter-netflix-eureka-client org.springframework.cloud spring-cloud-dependencies Edgware.SR5 pom import
package com.yun;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.circuitbreaker.EnableCircuitBreaker;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
@SpringBootApplication
@EnableDiscoveryClient
@EnableCircuitBreaker //这里使用注解开启Hystrix
public class CloudProviderApplication {
public static void main(String[] args) {
SpringApplication.run(CloudProviderApplication.class);
}
}
3.创建服务提供方测试类controller
package com.yun;
import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand;
import com.netflix.hystrix.contrib.javanica.annotation.HystrixProperty;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import java.util.concurrent.TimeUnit;
@RestController
@RequestMapping("/hello")
public class TestController {
@GetMapping("/testOne")
public String hello(){
return "你好呀，Hystrix";
}
//使用 @HystrixCommand: fallbackMethod出现熔断是调用方法快速返回。commandProperties进行参数的配置。
@HystrixCommand(fallbackMethod = "requestFailed",commandProperties = {@HystrixProperty(name = "execution.isolation.thread.timeoutInMilliseconds",value = "5000")})
@GetMapping("/testTwo")
public String timeout(){
try {
TimeUnit.SECONDS.sleep(3);
} catch (InterruptedException e) {
e.printStackTrace();
}
return "来了就别走了！";
}
public String requestFailed(){
return "请求失败！！！";
}
}
因为这个时候的超时时间为5秒，所以返回正常。
下面我们将超时时间改为2秒，返回下图说明@HystrixCommand配置起作用了：
2.yml文件4.0.0 com.yun cloud-consumer 1.0-SNAPSHOT cloud-consumer http://www.example.com UTF-8 1.7 1.7 junit junit 4.11 test org.springframework.cloud spring-cloud-starter-netflix-hystrix org.springframework.cloud spring-cloud-starter-netflix-eureka-client org.springframework.cloud spring-cloud-starter-openfeign org.springframework.cloud spring-cloud-dependencies Edgware.SR5 pom import
server:
port: 7002
eureka:
client:
service-url:
defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka
instance:
hostname: localhost
spring:
application:
name: cloud-consumer
feign: #这里一定要设置feign的超时时间配置，不设置会报错。
hystrix:
enbale: false #如果处理自身的容错就开启。开启方式与生产端不一样。
client:
config:
default:
connectTimeout: 10000
readTimeout: 600000
3.启动类
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.netflix.feign.EnableFeignClients;
import org.springframework.cloud.netflix.hystrix.EnableHystrix;
@SpringBootApplication
@EnableDiscoveryClient
@EnableFeignClients
@EnableHystrix //服务熔断，降级
public class CloudConsumberApplication {
public static void main(String[] args) {
SpringApplication.run(CloudConsumberApplication.class);
}
}
4.使用@FeignClient进行远程调用服务提供方
import org.springframework.cloud.netflix.feign.FeignClient;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.GetMapping;
@Component
//CLOUD-PROVIDER是提供方在服务中心注册的名称
@FeignClient(value = "CLOUD-PROVIDER")
public interface TestService {
@GetMapping("/hello/testOne")
public String hello();
@GetMapping("/hello/testTwo")
public String testTwo();
}
5.创建消费方测试类controller
package com.yun;
import com.netflix.hystrix.contrib.javanica.annotation.HystrixCommand;
import com.netflix.hystrix.contrib.javanica.annotation.HystrixProperty;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
@RequestMapping("/cloud")
public class CloudConsumberController {
//远程服务service
@Autowired
private TestService testService;
//自身启动服务降级
@HystrixCommand(fallbackMethod = "selfDowngrade",commandProperties = {@HystrixProperty(name = "execution.isolation.thread.timeoutInMilliseconds",value = "5000")})
@RequestMapping("/test")
public String test(){
return testService.testTwo();
}
public String selfDowngrade(){
return "自身降级服务启动";
}
}
