整理一下：

• @EnableEurekaServer     注册中心

• @EnableDiscoveryClient  提供服务

• @EnableFeignClients     消费者（Feign特有的，而且他自带断路器）

• @EnableHystrix          断路器

• @EnableHystrixDashboard 开启仪表盘

• @EnableZuulProxy        开启路由

 

 

 

事先声明，一定要按照我上面的pom写，因为各种版本冲突，哎。真是操蛋 。没必要追求最新的。刚开始能跑起来就行。不多说，看代码，如果有错误，看我另外一篇，。

新建一个服务中心：目的是让你的写的服务都注册上面，然后还需要写几个服务，然后还要写几个消费者

----------------------------------------------注册中心------------------------------------------------

erueka  pom.xml

      
          
       
        4.0.0
           
       
        com.example
           
       
        eureka
           
       
        0.0.1-SNAPSHOT
           
       
        jar
           
       
        eureka
           
       
        Demo project for Spring Boot
           
               
        
         org.springframework.boot
                
        
         spring-boot-starter-parent
                
        
         1.5.1.RELEASE
                
         
            
           
               
        
         UTF-8
                
        
         UTF-8
                
        
         1.8
                
        
         Camden.SR6
                
        
         5.1.30
            
           
               
                    
         
          org.springframework.cloud
                     
         
          spring-cloud-starter-eureka-server
                 
                
                    
         
          org.springframework.boot
                     
         
          spring-boot-starter-test
                     
         
          test
                 
            
           
               
                    
                         
          
           org.springframework.cloud
                          
          
           spring-cloud-dependencies
                          
          
           ${spring-cloud.version}
                          
          
           pom
                          
          
           import
                      
                 
            
           
               
                    
                         
          
           org.springframework.boot
                          
          
           spring-boot-maven-plugin
                      
                 
            
       
      

EurekaApplication.java 启动类

package com.example.demo;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;@SpringBootApplication@EnableEurekaServerpublic class EurekaApplication {    public static void main(String[] args) {        SpringApplication.run(EurekaApplication.class, args);    }}

application.yml

server:   port: 9999spring:  application:     name: eureka-service #    eureka server 相关配置eureka:   instance:     hostname: localhost   client:     registerWithEureka: false #表示是否将自己注册到Eureka Server上，默认为true     fetchRegistry: false #表示是否从Eureka Server上获取注册信息，默认为true     serviceUrl:       defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka #设置服务注册中心的URL

ok，一个最简单的注册中心就好了

 

----------------------------------------------注册服务------------------------------------------------

pom.xml

      
          
       
        4.0.0
           
       
        com.example
           
       
        eurekaclient
           
       
        0.0.1-SNAPSHOT
           
       
        jar
           
       
        eureka-client
           
       
        Demo project for Spring Boot
           
               
        
         org.springframework.boot
                
        
         spring-boot-starter-parent
                
        
         1.5.1.RELEASE
                
         
            
           
               
        
         UTF-8
                
        
         UTF-8
                
        
         1.8
                
        
         Camden.SR6
            
           
               
                    
         
          org.springframework.cloud
                     
         
          spring-cloud-starter-eureka
                 
                
                    
         
          org.springframework.boot
                     
         
          spring-boot-starter-test
                     
         
          test
                 
            
           
               
                    
                         
          
           org.springframework.cloud
                          
          
           spring-cloud-dependencies
                          
          
           ${spring-cloud.version}
                          
          
           pom
                          
          
           import
                      
                 
            
           
               
                    
                         
          
           org.springframework.boot
                          
          
           spring-boot-maven-plugin
                      
                 
            
       
      

EurekaClientApplication.java

package com.example.demo;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.cloud.client.discovery.EnableDiscoveryClient;@SpringBootApplication@EnableDiscoveryClientpublic class EurekaClientApplication {    public static void main(String[] args) {        SpringApplication.run(EurekaClientApplication.class, args);    }}

application.yml

server:   port: 9998spring:  application:     name: eureka-clienteureka:  client:    serviceUrl:      defaultZone: http://localhost:9999/eureka

 

 ----------------------------------------------负载均衡ribbon----------------------------------------

将注册服务再复制一份，端口改一下，spring.application.name.eureka-client      这个要一样 这样就配了一个小集群。然后用ribbon来创建消费者，配置一个简单的负载均衡服务

pom.xml

      
          
       
        4.0.0
           
       
        com.example
           
       
        springcloudribbon
           
       
        0.0.1-SNAPSHOT
           
       
        jar
           
       
        springcloud-ribbon
           
       
        Demo project for Spring Boot
           
               
        
         org.springframework.boot
                
        
         spring-boot-starter-parent
                
        
         1.5.1.RELEASE
                
         
            
           
               
        
         UTF-8
                
        
         UTF-8
                
        
         1.8
                
        
         Camden.SR6
            
           
               
                    
         
          org.springframework.boot
                     
         
          spring-boot-starter-web
                 
                
                    
         
          org.springframework.cloud
                     
         
          spring-cloud-starter-eureka
                 
                
                    
         
          org.springframework.boot
                     
         
          spring-boot-starter-test
                     
         
          test
                 
                
                    
         
          org.springframework.cloud
                     
         
          spring-cloud-starter-ribbon
                 
            
           
               
                    
                         
          
           org.springframework.cloud
                          
          
           spring-cloud-dependencies
                          
          
           ${spring-cloud.version}
                          
          
           pom
                          
          
           import
                      
                 
            
           
               
                    
                         
          
           org.springframework.boot
                          
          
           spring-boot-maven-plugin
                      
                 
            
           
               
                    
         
          spring-milestones
                     
         
          Spring Milestones
                     
         
          https://repo.spring.io/milestone
                     
                         
          
           false
                      
                 
            
       
      

SpringcloudRibbonApplication.java

package com.example.demo;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.cloud.client.discovery.EnableDiscoveryClient;import org.springframework.cloud.client.loadbalancer.LoadBalanced;import org.springframework.context.annotation.Bean;import org.springframework.web.client.RestTemplate;@SpringBootApplication@EnableDiscoveryClientpublic class SpringcloudRibbonApplication {    public static void main(String[] args) {        SpringApplication.run(SpringcloudRibbonApplication.class, args);    }    @Bean    @LoadBalanced    RestTemplate restTemplate() {        return new RestTemplate();    }}

HelloControler.java

package com.example.demo;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestParam;import org.springframework.web.bind.annotation.RestController;/** * Created by lilipo on 2018/5/3. */@RestControllerpublic class HelloControler {    @Autowired    HelloService helloService;    @RequestMapping(value = "/hi")    public String hi(@RequestParam String name){        return helloService.hiService(name);    }}

HelloService.java

package com.example.demo;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.stereotype.Service;import org.springframework.web.client.RestTemplate;/** * Created by lilipo on 2018/5/3. */@Servicepublic class HelloService {    @Autowired    RestTemplate restTemplate;    public String hiService(String name) {        return restTemplate.getForObject("http://eureka-client/hi?name="+name,String.class);    }}

 

 

如果正确启动的话，你会在浏览器上看到端口轮询出现。就说明负载均衡配置好了。实在是太简单了。参考博客：

 

  ----------------------------------------------服务消费者（Feign）----------------------------------------

Feign是一个声明式的伪Http客户端，它使得写Http客户端变得更简单。使用Feign，只需要创建一个接口并注解。它具有可插拔的注解特性，可使用Feign 注解和JAX-RS注解。Feign支持可插拔的编码器和解码器。Feign默认集成了Ribbon，并和Eureka结合，默认实现了负载均衡的效果。

简而言之：

• Feign 采用的是基于接口的注解
• Feign 整合了ribbon

pom.xml

      
          
       
        4.0.0
           
       
        com.example
           
       
        springcloudfeign
           
       
        0.0.1-SNAPSHOT
           
       
        jar
           
       
        springcloud-feign
           
       
        Demo project for Spring Boot
           
               
        
         org.springframework.boot
                
        
         spring-boot-starter-parent
                
        
         1.5.1.RELEASE
                
         
            
           
               
        
         UTF-8
                
        
         UTF-8
                
        
         1.8
                
        
         Camden.SR6
                
        
         5.1.30
            
           
               
                    
         
          org.springframework.cloud
                     
         
          spring-cloud-starter-eureka
                 
                
                    
         
          org.springframework.cloud
                     
         
          spring-cloud-starter-feign
                 
                
                    
         
          org.springframework.boot
                     
         
          spring-boot-starter-web
                 
                
                    
         
          org.springframework.boot
                     
         
          spring-boot-starter-test
                     
         
          test
                 
            
           
               
                    
                         
          
           org.springframework.cloud
                          
          
           spring-cloud-dependencies
                          
          
           ${spring-cloud.version}
                          
          
           pom
                          
          
           import
                      
                 
            
           
               
                    
                         
          
           org.springframework.boot
                          
          
           spring-boot-maven-plugin
                      
                 
            
       
      

SpringcloudFeignApplication.java （@EnableFeignClients注解开启Feign的功能）

package com.example.demo;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;@SpringBootApplication@EnableDiscoveryClient@EnableFeignClientspublic class SpringcloudFeignApplication {    public static void main(String[] args) {        SpringApplication.run(SpringcloudFeignApplication.class, args);    }}

HiController.java

package com.example.demo;import org.springframework.beans.factory.annotation.Autowired;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import org.springframework.web.bind.annotation.RequestParam;import org.springframework.web.bind.annotation.RestController;/** * Created by lilipo on 2018/5/3. */@RestControllerpublic class HiController {    @Autowired    SchedualServiceHi schedualServiceHi;    @RequestMapping(value = "/hi",method = RequestMethod.GET)    public String sayHi(@RequestParam String name){        return schedualServiceHi.sayHiFromClientOne(name);    }}

SchedualServiceHi.java （定义一个feign接口，通过@ FeignClient（“服务名”），来指定调用哪个服务。比如在代码中调用了service-hi服务的“/hi”接口）

package com.example.demo;import org.springframework.cloud.netflix.feign.FeignClient;import org.springframework.stereotype.Service;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import org.springframework.web.bind.annotation.RequestParam;/** * Created by lilipo on 2018/5/3. */@FeignClient(value = "eureka-client")@Servicepublic interface  SchedualServiceHi {    @RequestMapping(value = "/hi",method = RequestMethod.GET)    String sayHiFromClientOne(@RequestParam(value = "name") String name);}

 

如果正确启动，那么会实现和ribbon一样的效果。默认有负载均衡的作用，更加简单。

参考博客：

----------------------------------------------断路器（Hystrix）----------------------------------------

断路器（Hystrix）的作用就是当你的调用服务的时候，注册的服务挂了，这时候会走一个你指定的方法，而不是一直等待或者报错。分别从ribbon和Feign两种情况做演示

只是改造而已，在ribbon的项目上增加下面这个依赖

 

         
      
       org.springframework.cloud
          
      
       spring-cloud-starter-hystrix
      
     

 

 

 

在启动类上增加@EnableHystrix注解

改造HelloService类，在hiService方法上加上@HystrixCommand注解。该注解对该方法创建了熔断器的功能，并指定了fallbackMethod熔断方法，熔断方法直接返回了一个字符串，字符串为”hi,”+name+”,sorry,error!”，代码如下：

 

@Servicepublic class HelloService {    @Autowired    RestTemplate restTemplate;    @HystrixCommand(fallbackMethod = "hiError")    public String hiService(String name) {        return restTemplate.getForObject("http://SERVICE-HI/hi?name="+name,String.class);    }    public String hiError(String name) {        return "hi,"+name+",sorry,error!";    }}

 

当 service-hi 工程不可用的时候，service-ribbon调用 service-hi的API接口时，会执行快速失败，直接返回一组字符串，而不是等待响应超时，这很好的控制了容器的线程阻塞。

 

 

 

Feign中使用断路器

Feign是自带断路器的，在D版本的Spring Cloud中，它没有默认打开。需要在配置文件中配置打开它，在配置文件加以下

 

feign.hystrix.enabled=true

基于service-feign工程进行改造，只需要在FeignClient的SchedualServiceHi接口的注解中加上fallback的指定类就行了：

@FeignClient(value = "service-hi",fallback = SchedualServiceHiHystric.class)public interface SchedualServiceHi {    @RequestMapping(value = "/hi",method = RequestMethod.GET)    String sayHiFromClientOne(@RequestParam(value = "name") String name);}

SchedualServiceHiHystric需要实现SchedualServiceHi 接口，并注入到Ioc容器中，代码如下：

@Componentpublic class SchedualServiceHiHystric implements SchedualServiceHi {    @Override    public String sayHiFromClientOne(String name) {        return "sorry "+name;    }}

 

 

------------------------Hystrix Dashboard (断路器：Hystrix 仪表盘)-------------------------------------

基于service-ribbon 改造

在pom中增加依赖

 

                  
       
        org.springframework.boot
                   
       
        spring-boot-starter-actuator
               
              
                  
       
        org.springframework.cloud
                   
       
        spring-cloud-starter-hystrix-dashboard
               
              
                  
       
        org.springframework.cloud
                   
       
        spring-cloud-starter-hystrix
               
      

 

 

 

在主程序启动类中加入@EnableHystrixDashboard注解，开启hystrixDashboard：

 

ok，访问：http://192.168.1.28:9996/hystrix  端口号是你这个ribbon项目的端口号  会出现一个熊猫界面

第一个框填上http://localhost:9996/hystrix.stream   第二个Title  随便填。自定义名字 然后点击下面的按钮会出现另外一个界面

 

基于service-ribbon 改造             （和ribbon的差不多，但是有坑，依赖问题，需要注意一下。 ）

添加依赖

                  
       
        org.springframework.boot
                   
       
        spring-boot-starter-actuator
                   
       
        1.5.10.RELEASE
               
              
                  
       
        org.springframework.cloud
                   
       
        spring-cloud-starter-hystrix-dashboard
                   
       
        RELEASE
               
      

 

在主程序启动类中加入@EnableHystrixDashboard注解，开启hystrixDashboard：   

 

 参考博客：

 

------------------------------------------路由网关(zuul)-----------------------------------------------

新建一个zuul网关项目

pom.xml

 

      
          
       
        4.0.0
           
       
        com.example
           
       
        springcloudzuul
           
       
        0.0.1-SNAPSHOT
           
       
        jar
           
       
        springcloud-zuul
           
       
        Demo project for Spring Boot
           
               
        
         org.springframework.boot
                
        
         spring-boot-starter-parent
                
        
         1.5.1.RELEASE
                
         
            
           
               
        
         UTF-8
                
        
         UTF-8
                
        
         1.8
                
        
         Camden.SR6
                
        
         5.1.30
            
           
               
                    
         
          org.springframework.cloud
                     
         
          spring-cloud-starter-eureka
                 
                
                    
         
          org.springframework.cloud
                     
         
          spring-cloud-starter-zuul
                 
                
                    
         
          org.springframework.boot
                     
         
          spring-boot-starter-web
                 
                
                    
         
          org.springframework.boot
                     
         
          spring-boot-starter-test
                     
         
          test
                 
            
           
               
                    
                         
          
           org.springframework.cloud
                          
          
           spring-cloud-dependencies
                          
          
           ${spring-cloud.version}
                          
          
           pom
                          
          
           import
                      
                 
            
           
               
                    
                         
          
           org.springframework.boot
                          
          
           spring-boot-maven-plugin
                      
                 
            
       
      

 

SpringcloudZuulApplication.java(@EnableZuulProxy注解开启路由)

package com.example.demo;import org.springframework.boot.SpringApplication;import org.springframework.boot.autoconfigure.SpringBootApplication;import org.springframework.cloud.netflix.eureka.EnableEurekaClient;import org.springframework.cloud.netflix.zuul.EnableZuulProxy;@EnableZuulProxy@EnableEurekaClient@SpringBootApplicationpublic class SpringcloudZuulApplication {    public static void main(String[] args) {        SpringApplication.run(SpringcloudZuulApplication.class, args);    }}

 

 application.yml

eureka:  client:    serviceUrl:      defaultZone: http://localhost:9999/eureka/server:  port: 9994spring:  application:    name: service-zuulzuul:  routes:    api-a:      path: /api-a/**      serviceId: service-ribbon    api-b:      path: /api-b/**      serviceId: service-feign

首先指定服务注册中心的地址为，服务的端口为9994，服务名为service-zuul；以/api-a/ 开头的请求都转发给service-ribbon服务；以/api-b/开头的请求都转发给service-feign服务；

 访问：  和    看结果 参考博客：