spring cloud:feign-hystrix

小鱼儿 2022-01-05 12:57 256阅读 0赞

## producer ##

### 1. File-->new spring starter project ###

### 2.add dependency ###

### 3.Edit application.yml ###

server:
      port: 8005
    spring:
      application:
        name: producer
        
    eureka:
      client:
        service-url:
          defaultZone: http://localhost:8761/eureka/

### 4.program ###

package com.smile;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
    
    @SpringBootApplication
    @EnableEurekaClient
    public class ProducerApplication {
    
        public static void main(String[] args) {
            SpringApplication.run(ProducerApplication.class, args);
        }
    
    }

package com.smile.controller;
    
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestParam;
    import org.springframework.web.bind.annotation.RestController;
    
    @RestController
    public class ProducerController {
        
        @RequestMapping("/getHello")
        public String getGetHello(@RequestParam String name) {
            return "hello "+name;
        }
    }

### 5.Run  ###

visit:  http://localhost:8005/getHello?name=smile

![1690567-20190520140348400-1391467944.png][]

## consumer ##

### 1. File-->new spring starter project ###

### 2.add dependency ###

<dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-openfeign</artifactId>
            </dependency>

### 3.Edit application.yml ###

server:
      port: 8006
    spring:
      application:
        name: consumer
        
    eureka:
      client:
        service-url:
          defaultZone: http://localhost:8761/eureka/

### 4.program ###

package com.smile;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
    import org.springframework.cloud.openfeign.EnableFeignClients;
    
    @SpringBootApplication
    @EnableEurekaClient
    @EnableFeignClients
    public class ConsumerApplication {
    
        public static void main(String[] args) {
            SpringApplication.run(ConsumerApplication.class, args);
        }
    
    }

package com.smile.controller;
    
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.PathVariable;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import com.smile.remote.HelloService;
    
    @RestController
    public class ConsumerController {
        
        @Autowired
        HelloService helloService;
        
        @RequestMapping("/hello/{name}")
        public String helol(@PathVariable("name") String name){
            return helloService.getHello(name);
        }
    }

package com.smile.remote;
    
    import org.springframework.cloud.openfeign.FeignClient;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestParam;
    
    @FeignClient(name = "producer")
    public interface HelloService {
        
        @RequestMapping("/getHello")
        public String getHello(@RequestParam String name);
    }

### 5.Run ###

![1690567-20190520140856014-365482196.png][]

负载均衡

new -->srping starter project -->producer-1

修改port

server:
      port: 8004
    spring:
      application:
        name: producer
        
    eureka:
      client:
        service-url:
          defaultZone: http://localhost:8761/eureka/

其它均与producer一致

打包启动后，在eureka就会发现两个服务提供者，如下图：

![1690567-20190520142643292-313195650.png][]

然后在浏览器再次输入：`http://localhost:9001/hello/wang` 进行测试：

第一次返回结果：`hello wang`

第二次返回结果：hello wang,this is producer 1

不断的进行测试下去会发现两种结果交替出现，说明两个服务中心自动提供了服务均衡负载的功能。如果我们将服务提供者的数量在提高为N个，测试结果一样，请求会自动轮询到每个服务端来处理。

hystrix

1.new file-->spring starter project-->consumer-feign-hystrix

2.add dependency

<dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-starter-openfeign</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>

3 application.yml

server:
      port: 8007
    spring:
      application:
        name: consumer-feign-hystrix
        
    eureka:
      client:
        service-url:
          defaultZone: http://localhost:8761/eureka/
          
          
    feign:
      hystrix:
        enabled: true

4.program

package com.smile;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
    import org.springframework.cloud.netflix.hystrix.EnableHystrix;
    import org.springframework.cloud.openfeign.EnableFeignClients;
    
    @SpringBootApplication
    @EnableEurekaClient
    @EnableFeignClients
    @EnableHystrix
    public class ConsumerFeignHystrixApplication {
    
        public static void main(String[] args) {
            SpringApplication.run(ConsumerFeignHystrixApplication.class, args);
        }
    
    }

package com.smile.remote;
    
    import org.springframework.cloud.openfeign.FeignClient;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestParam;
    
    @FeignClient(name = "producer",fallback = HelloServiceHystrix.class)
    public interface HelloService {
        
        @RequestMapping("/getHello")
        public String getHello(@RequestParam String name);
    }

package com.smile.remote;
    
    import org.springframework.stereotype.Component;
    
    @Component
    public class HelloServiceHystrix implements HelloService{
    
        @Override
        public String getHello(String name) {
            return "hello "+name+",this is hystrix!";
        }
    
    }

5.test

visit [http://localhost:8007/hello/wang][http_localhost_8007_hello_wang] 以下两种结果交替出现，项目正常

hello wang

hello wang,this is producer 1

停止 producer 和 producer-1 再次访问

hello wang,this is hystrix!

转载于:https://www.cnblogs.com/alittlesmile/p/10893969.html

[1690567-20190520140348400-1391467944.png]: /images/20211229/c5a8b05b3a08419480cdfa13ad10629d.png
[1690567-20190520140856014-365482196.png]: /images/20211229/e68acce468a8421e966e12fcd44601a9.png
[1690567-20190520142643292-313195650.png]: /images/20211229/01865a099ec34ce2baea7b663945a07e.png
[http_localhost_8007_hello_wang]: http://localhost:8007/hello/wang