SpringCloud笔记

eureka服务注册中心

 <!--eureka-server服务端 -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka-server</artifactId>
        </dependency>
server:
  port: 7001

eureka:
  instance:
    hostname: localhost  #eureka服务端的实例名称
  client:
    register-with-eureka: false     #false表示不向注册中心注册自己。
    fetch-registry: false     #false表示自己端就是注册中心，我的职责就是维护服务实例，并不需要去检索服务
    service-url:
      defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/       #设置与Eureka Server交互的地址查询服务和注册服务都需要依赖这个地址（单机）。
@EnableEurekaServer

http://localhost:7001/

eureka集群

修改C:\Windows\System32\drivers\etc 下的hosts文件，添加

127.0.0.1 eureka7001.com
127.0.0.1 eureka7002.com
127.0.0.1 eureka7003.com

7001向7002和7003eureka注册

server:
  port: 7001

eureka:
  instance:
    hostname: eureka7001.com  #eureka服务端的实例名称
  client:
    register-with-eureka: false     #false表示不向注册中心注册自己。
    fetch-registry: false     #false表示自己端就是注册中心，我的职责就是维护服务实例，并不需要去检索服务
    service-url:
      defaultZone: http://eureka7002.com:7002/eureka/,http://eureka7003.com:7003/eureka/

7002向7001和7003eureka注册

server:
  port: 7002

eureka:
  instance:
    hostname: eureka7002.com  #eureka服务端的实例名称
  client:
    register-with-eureka: false     #false表示不向注册中心注册自己。
    fetch-registry: false     #false表示自己端就是注册中心，我的职责就是维护服务实例，并不需要去检索服务
    service-url:
      defaultZone: http://eureka7001.com:7001/eureka/,http://eureka7003.com:7003/eureka/

7003eureka向7001和7002eureka注册

server:
  port: 7003

eureka:
  instance:
    hostname: eureka7003.com  #eureka服务端的实例名称
  client:
    register-with-eureka: false     #false表示不向注册中心注册自己。
    fetch-registry: false     #false表示自己端就是注册中心，我的职责就是维护服务实例，并不需要去检索服务
    service-url:
      defaultZone: http://eureka7001.com:7001/eureka/,http://eureka7002.com:7002/eureka/

EurekaClient向eurekaServer注册

eureka:
  client:
    service-url:
      #defaultZone: http://localhost:7001/eureka           #单机版
      defaultZone: http://eureka7001.com:7001/eureka/,http://eureka7002.com:7002/eureka/,http://eureka7003.com:7003/eureka/,            #集群

向服务中心注册微服务

	<!-- 将微服务provider侧注册进eureka -->
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-eureka</artifactId>
		</dependency>
		<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
@EnableEurekaClient
server:
  port: 8001

spring:
  application:
    name: SpringCloudDemo-dept

eureka:
  client:
    service-url:
      defaultZone: http://localhost:7001/eureka

Ribbon(客户端（消费者）的负载均衡)

Ribbon+restTemplate

使用Ribbon

Ribbon和Eureka整合后可以直接调用服务而不用再关心地址和端口号

提供者要对完暴露统一的名称，下面属性不能改

spring:
  application:
    name: SpringCloudDemo-dept

 <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </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-ribbon</artifactId>
        </dependency>
eureka:
  client:
    register-with-eureka: false
    service-url:
      defaultZone: http://localhost:7001/eureka/

server:
  port: 80

@LoadBalanced

    @Bean
    @LoadBalanced//重点，重点，重点
    public RestTemplate getRestTemplate() {
        return new RestTemplate();
    }

在客户端启动类上添加

@EnableEurekaClient

修改controller

   //private static final String REST_URL_PREFIX = "http://localhost:8001";
    private static final String REST_URL_PREFIX = "http://SPRINGCLOUDDEMO-DEPT";

负载均衡（默认轮询算法）

使用系统定义的某个算法

	@Bean
	public IRule myRule()
	{
		//return new RoundRobinRule();
		//return new RandomRule();//达到的目的，用我们重新选择的随机算法替代默认的轮询。
		return new RetryRule();
	}

使用自定义负载均衡算法

在客户端加

//在启动该微服务的时候就能去加载我们的自定义Ribbon配置类，从而使配置生效
//name属性为哪一个微服务名称
//configuration属性为自定义负载均衡算法
@RibbonClient(name="MICROSERVICECLOUD-DEPT",configuration=MySelfRule.class)

在启动类扫描不到的目录下 创建自定义算法

xxx

Feign((客户端)负载均衡，接口风格)

客户端要添加

 <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-feign</artifactId>
    </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>

appliaction.yml

spring:
  application:
    name: consumer-dept-80
eureka:
  client:
    register-with-eureka: false
    service-url:
      defaultZone: http://eureka7001.com:7001/eureka/
server:
  port: 80

value表示调用哪个微服务

@Component
@FeignClient(value = "MICROSERVICECLOUD-DEPT")
public interface DeptClientService
{
    @RequestMapping(value = "/dept/get/{id}", method = RequestMethod.GET)
    public Dept get(@PathVariable("id") long id);

    @RequestMapping(value = "/dept/list", method = RequestMethod.GET)
    public List<Dept> list();

    @RequestMapping(value = "/dept/add", method = RequestMethod.POST)
    public boolean add(Dept dept);

修改客户端工程

@RestController
public class DeptController_Consumer
{
    @Autowired
    private DeptClientService service;

    @RequestMapping(value = "/consumer/dept/get/{id}")
    public Dept get(@PathVariable("id") Long id)
    {
        return this.service.get(id);
    }

   
}

在客户端启动类上添加

@EnableEurekaClient
@EnableFeignClients(basePackages= {"com.imooc.springcloud"})

Hystrix(断路器，当服务拥堵或者异常时候返回一个合理的值)

整合feign

在客户端添加

 <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </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>

在api项目中创建一个实现FallbackFactory接口的实现类，实现Fallback

@Component  //不要忘记添加//不要忘记添加//不要忘记添加//不要忘记添加//不要忘记添加
public class DeptClientServiceFallbackFactory implements FallbackFactory<DeptClientService> {
    @Override
    public DeptClientService create(Throwable throwable) {
        return new DeptClientService() {
            @Override
            public Dept get(long id) {
                return new Dept().setDeptno(id).setDname("该ID：" + id + "没有没有对应的信息,Consumer客户端提供的降级信息,此刻服务Provider已经关闭")
                        .setDb_source("no this database in MySQL");
            }

            @Override
            public List<Dept> list() {
                return null;
            }

            @Override
            public boolean add(Dept dept) {
                return false;
            }
        };
    }
}

在service接口上添加

@FeignClient(value = "MICROSERVICECLOUD-DEPT",fallbackFactory=DeptClientServiceFallbackFactory.class)

在客户端添加

feign:
  hystrix:
    enabled: true

在提供端添加

@EnableCircuitBreaker
@EnableFeignClients(basePackages= {"com.example"})

hystrixdashboard (×××错误)

<!-- hystrix和 hystrix-dashboard相关 -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-hystrix</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-hystrix-dashboard</artifactId>
        </dependency>
@EnableHystrixDashboard
server:
  port: 9001
 //  //Howard 2019-02-21 add for HystrixDashboard
    @Bean
    public ServletRegistrationBean getServlet(){
        HystrixMetricsStreamServlet streamServlet = new HystrixMetricsStreamServlet();
        ServletRegistrationBean registrationBean = new ServletRegistrationBean(streamServlet);
        registrationBean.setLoadOnStartup(1);
        registrationBean.addUrlMappings("/hystrix.stream");
        registrationBean.setName("HystrixMetricsStreamServlet");
        return registrationBean;
    }

要监控的服务添加

<!-- actuator监控信息完善 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>

http://localhost:9001/hystrix

Zuul(路由网关，可以理解为在服务前加了一个门卫)

功能：代理+路由+过滤

 <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </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-zuul</artifactId>
        </dependency>
@EnableZuulProxy

其中：

zuul.igored-services 表示不允许用服务名称访问

prefix:前缀

zuul.rotes.xxx.serivceId和zuul.rotes.xxx.path是一对

所有的请求都走zuul，即（ip:端口/前缀/(zuul.rotes.xxx.path)/controller中的请求地址）

http://localhost:9527/atguigu/mydept/get/1

server: 
  port: 9527
 
spring: 
  application:
    name: zuul-9587
 
eureka: 
  client: 
    service-url: 
      defaultZone: http://eureka7001.com:7001/eureka,http://eureka7002.com:7002/eureka,http://eureka7003.com:7003/eureka  
  instance:
    instance-id: gateway-9527.com
    prefer-ip-address: true 
 
 
zuul: 
  #ignored-services: microservicecloud-dept
  prefix: /atguigu
  ignored-services: "*"
  routes: 
    mydept.serviceId: microservicecloud-dept
    mydept.path: /mydept/**
 
info:
  app.name: atguigu-microcloud
  company.name: www.atguigu.com

Config

小案例：

用一个eurekaserver从github上读数据（eureka的配置文件），然后eurek-client端（也就是eureka）从configServer端读取配置文件并且加载

前提：

你必须可以用写程序的电脑对github仓库进行读写，否则出现认证错误

ConfigServer

在github有一个名称为microservicecloud-config的仓库，里面有一个文件config-eureka.yml,区别在于端口

spring:
  profiles:
    active: -dev
---
server:
  port: 7001
spring:
  profiles: dev
  application:
    name: microservicecloud-config-eureka-client
eureka:
  instance:
    hostname: localhost #eureka服务端的实例名称
  client:
    register-with-eureka: false     #false表示不向注册中心注册自己。
    fetch-registry: false     #false表示自己端就是注册中心，我的职责就是维护服务实例，并不需要去检索服务
    service-url:
      defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/       


---
server:
  port: 8001
spring:
  profiles: test
  application:
    name: microservicecloud-config-eureka-client
eureka:
  instance:
    hostname: localhost #eureka服务端的实例名称
  client:
    register-with-eureka: false     #false表示不向注册中心注册自己。
    fetch-registry: false     #false表示自己端就是注册中心，我的职责就是维护服务实例，并不需要去检索服务
    service-url:
      defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/

pom

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-config-server</artifactId>
        </dependency>

yml

server:
  port: 3344

spring:
  application:
    name:  config-server-3344
  cloud:
    config:
      server:
        git:
          uri: git@github.com:cbeann/microservicecloud-config.git #GitHub上面的git仓库名字
          username: bean
          password: 17863961702
@EnableConfigServer

config-eureka为github仓库中文件名称 -dev -test为后缀

http://localhost:3344/config-eureka-test.yml

http://localhost:3344/config-eureka-dev.yml

ConfigClient

 <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-config</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
        </dependency>

bootstrap.yml

spring:
  cloud:
    config:
      name: config-eureka #需要从github上读取的资源名称，注意没有yml后缀名
      profile: dev   #本次访问的配置项
      label: master
      uri: http://localhost:3344  #本微服务启动后先去找3344号服务，通过SpringCloudConfig获取GitHub的服务地址

application.yml

spring:
  application:
    name: config-eureka

Spring Cloud Sleuth（服务链路追踪）

功能：查看服务直接的调用关系

1）启动Zipkin Server

下载Zipkin Server

https://dl.bintray.com/openzipkin/maven/io/zipkin/java/zipkin-server/

java -jar zipkin-server-2.11.6-exec.jar

链接：https://pan.baidu.com/s/11vyNQ9k551foEjeRaBY2Zg 提取码：k9ba

localhost:9411

2）新建项目A

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-zipkin</artifactId>
        </dependency>
spring:
  zipkin:
    base-url: http://localhost:9411
  application:
    name: zipkin-service-a

server:
  port: 8988

3）新建项目B

依赖和A一样

yml中端口和名称需要修改

B中有一个restTemplate可以调用A中的方法

4）结果

先请求一下B项目，使其调用A

然后点击下图中的A就可以出现下图的B

小细节（for eureka client）

eureka:
  client:
    service-url:
      defaultZone: http://localhost:7001/eureka

  instance:
    instance-id: SpringCloudDemo-provider-dept-8001          #.小细节：Status别名
    prefer-ip-address: true                                  #.小细节：访问路径可以显示IP地址

 <!-- actuator监控信息完善 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>

点击上图A后进入的界面信息

info:
  app.name: ABC-SpringCloudDemo
  company.name: CDEF

学习感悟

1）学习SpringCloud你要用对工具，正常的方式是通过打对勾的方式添加组件

2）添加的依赖可能不同，但是效果可能一样，这一点我没有弄清楚，比如下面两个依赖

 <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
        </dependency>
 <!--eureka-server服务端 -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka-server</artifactId>
        </dependency>

3）动手实践，加上自己的想法