spring cloud NETFLIX

1.什么是微服务

​ 微服务就是将一个单体应用的架构拆分为一个个独立运行的程序，他们之间通过http协议通信，这些独立运行的程序可以采用不同的编程语言，不同的存储技术

2.什么是springcloud

springcloud是微服务放假的一种规范，它整合了许多市面上流行的框架，是一种一站式的解决方案，微服务将要面对的许多问题

1.服务注册与发现

2.负载均衡

3.服务熔断和限流

4.路由

。。。。

刚好springcloud Netflix就能解决这些方案：

1.springcloud eureka（服务注册与发现）

2.springcloud ribbon ，springcloud feign（负载均衡）

3.springcloud hystrix（服务熔断和限流）

4.springcloud zuul （路由网管）

5.springcloud config（配置统一管理）

3.springcloud eureka （单机）

springcloud eureka是Netflix卡原组织提供的一个服务高可用的解决方案

1.eureka服务端

1.导入依赖

<!--springcloud-->

<dependency>

​    <groupId>org.springframework.cloud</groupId>

​    <artifactId>spring-cloud-dependencies</artifactId>    

​	<version>Greenwich.SR1</version>

​    <type>pom</type>

​    <scope>import</scope>

</dependency>



<!--springcloud eureka server-->

<dependency>

​	<groupId>org.springframework.cloud</groupId>

​	<artifacId>spring-cloud-starter-netflix-eureka-server</artifacId>

</dependencity>

2.application.yml/application.properties配置

server:
  port: 7001 #设置端口号

#eureka配置服务
eureka:
  instance:
    hostname: localhost #设置eureka的主机名
  client:
    register-with-eureka: false #表示不向eureka注册中心注册自己
    fetch-registry: false #表示自己是服务端
    service-url:
      defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka
      #设置eureka的

3.添加注解

@SpringBootApplication //springboot启动注解
@EnableEurekaServer //eureka客户端启动注解
public class EurekaServer_7001 {
    public static void main(String[] args) {
        SpringApplication.run(EurekaServer_7001.class);
    }
}

4.运行测试

2.eureka的provider配置

1.添加依赖

<!--springcloud-client-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-				  client</artifactId>
        </dependency>

2.application.yml/application.properties配置

#端口
server:
  port: 8001
spring:
  application:
    name: springcloud-mapper #指定项目的名字
eureka:
  client:
    service-url:
      defaultZone: http://localhost:7001/eureka #要将此服务注册到的地址
  instance:
    instance-id: ${spring.application.name}:${server.port}
    #指定eureka服务注册中心显示微服务的名字

3.添加注解

@SpringBootApplication
@EnableEurekaClient //启动eureka客户端
public class springcloud_mapper {

public static void main(String[] args) {
    SpringApplication.run(springcloud_mapper.class);
}
}

4.运行测试

3.eureka customer端

可以通过resttemplate调用远程方法访问

1.provider提供方法

@GetMapping("/user/findId/{id}")
public User findId(@PathVariable("id") Integer id){
    return userService.findId(id);
};

2.customer注册resttemplate

@Configuration
public class RestTemplateConfig {
    @Bean
    public RestTemplate restTemplate(){
        return new RestTemplate();
    }
}

3.customer的controller

  @Autowired
  private RestTemplate restTemplate;
  
  private final String MAPPER_URL="http://localhost:7001";

@GetMapping("/user/findId/{id}")
public User findId(@PathVariable("id") Integer id){
    return 			 restTemplate.getForObject(MAPPER_URL+"/user/findId/"+id,User.class);
};

4.application.yml/application.application配置

server:
  port: 9001 #设置端口号

5.运行测试

4.springcloud eureka（集群）

1.赋值三个项目

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2.application.yml/application.properties配置

1.7001

server:
  port: 7001

#eureka
eureka:
  instance:
    hostname: localhost1
  client:
    register-with-eureka: false #表示是否想eureka注册中心注册自己
    fetch-registry: false #表示自己是服务端
    service-url:
      defaultZone: http://localhost2:7002/eureka,http://localhost3:7003/eureka

2.7002

server:
  port: 7002

#eureka
eureka:
  instance:
    hostname: localhost2
  client:
    register-with-eureka: false #表示是否想eureka注册中心注册自己
    fetch-registry: false #表示自己是服务端
    service-url:
      defaultZone: http://localhost1:7001/eureka,http://localhost3:7003/eureka

3.7003

server:
  port: 7003

#eureka
eureka:
  instance:
    hostname: localhost3
  client:
    register-with-eureka: false #表示是否想eureka注册中心注册自己
    fetch-registry: false #表示自己是服务端
    service-url:
      defaultZone: http://localhost1:7001/eureka,http://localhost2:7002/eureka

3.运行测试

6.springcloud ribbon配置

springcloud ribbon是一个客户端负载均衡的工具，通过springcloud的封装，可以让我们轻松将面向服务的rest模板请求自动转换成客户端负载均衡的服务调用

1.添加依赖

 <!--robbin-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-ribbon</artifactId>
        </dependency>

​    <!--eureka-->
​    <dependency>
​        <groupId>org.springframework.cloud</groupId>
​        <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
​    </dependency>

2.是resttemplate拥有调用eureka的功能

 	@Bean
    @LoadBalanced //该注解使resttemplates拥有eureka访问的功能
    public RestTemplate restTemplate(){
        return new RestTemplate();
    }

3.application.yml/application.properties

server:
  port: 9001

eureka:
  client:
    service-url:
      defaultZone: http://localhost:7001/eureka
    register-with-eureka: false #不像eureka注册中心注册自己

4.controller

通过eureka服务注册中心的名字进行调用

@Autowired
private RestTemplate restTemplate;

private final String MAPPER_URL="http://SPRINGCLOUD-MAPPER";

@GetMapping("/user/findId/{id}")
public User findId(@PathVariable("id") Integer id){
    return restTemplate.getForObject(MAPPER_URL+"/user/findId/"+id,User.class);
};

5.调用测试

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7.springcloud Feign

springcloud feign是基于ribbon开发的一个面向接口的为服务客户端负载均衡的工具

1.添加依赖

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

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

2.创建接口并配置feign

@FeignClient(value = "SPRINGCLOUD-MAPPER")
public interface UserInterface {
    @GetMapping("/user/findId/{id}")
    public User findId(@PathVariable("id") Integer id);
}

3.application.yml/application.properties

server:
  port: 9002

eureka:
  client:
    register-with-eureka: false
    service-url:
      defaultZone: http://localhost:7001/eureka

4.启动feign

@SpringBootApplication
@EnableEurekaClient
@EnableFeignClients(basePackages = {"com.hao.springcloud"})#指定接口所在的位置
public class feignApplication {
    public static void main(String[] args) {
        SpringApplication.run(feignApplication.class,args);
    }
}

5.controller

  @Autowired
  private UserInterface userInterface;

@GetMapping("/user/findId/{id}")
public User findId(@PathVariable("id") Integer id){
    return userInterface.findId(id);
}

6.运行测试

8.springcloud hystrix

微服务中当一个服务调用另一个服务时，因为网络或者自身的原因出现了问题，那么调用者就会等待被调用者的回应，随着时间的增长，越来越多的服务会访问到这个项目，就会引起雪崩效应，springcloud hystrix就是为了解决这个问题，springclou hystrix分为服务熔断与服务降级

服务熔断是“好死不如赖活着”,当被调用者的某个业务出现问题的时候，调用hystrix提供的备用方法，使其返回某些信息，不至于导致服务雪崩

服务降级：加入有a，b，c三个微服务，在某一个时间a的微服务的访问量猛然整多，导致a服务随时可能出现问题，而c的微服务的访问量比较少，那么就忍痛将c的微服务关掉，从客户端返回个客户一些信息，将资源分配给a服务

1.服务熔断

1.添加依赖

<!--springcloud-client-->
        <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>

2.启动hystrix

@SpringBootApplication
@EnableEurekaClient //启动eureka客户端
@EnableCircuitBreaker //开启hystrix
public class springcloud_mapper {

public static void main(String[] args) {
    SpringApplication.run(springcloud_mapper.class);
}
}

3.controller

@GetMapping("/user/findId/{id}")
    @HystrixCommand(fallbackMethod = "findIdHystrix")
    public User findId(@PathVariable("id") Integer id){
        User id1 = userService.findId(id);
        if(id1==null){
            throw new RuntimeException("错误");
        }
        return id1;
    };

public User findIdHystrix(Integer  id){
    return new User(id,"错误");
}

4.application.yml/application.properties

#端口
server:
  port: 8001
  
spring:
  application:
    name: springcloud-mapper #指定项目的名字
    
eureka:
  client:
    service-url:
      defaultZone: http://localhost:7001/eureka #要将此服务注册到的地址
  instance:
    instance-id: ${spring.application.name}:${server.port} #指定显示微服务的名字

5.调用测试

2.服务降级（fegin配合使用)

1.添加依赖

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

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

​    <!--hystrix-->
​    <dependency>
​        <groupId>org.springframework.cloud</groupId>
​        <artifactId>spring-cloud-starter-netflix-hystrix</artifactId>
​    </dependency>

2.修改fegin接口

@FeignClient(value = "SPRINGCLOUD-MAPPER",fallbackFactory = UserFackbackFactory.class)
@Configuration
public interface UserInterface {

    @PostMapping("/user/insert")
    public boolean insert(User user);

    @GetMapping("/user/findId/{id}")
    public User findId(@PathVariable("id") Integer id);

    @GetMapping("/user/findAll")
    public List<User> findAll();

}

3.新建UserFackbackFactory接口并继承FallbackFactory

@Component
public class UserFackbackFactory implements FallbackFactory {
    @Override
    public UserInterface create(Throwable throwable) {
        return new UserInterface() {
            @Override
            public boolean insert(User user) {
                return false;
            }

​        @Override
​        public User findId(Integer id) {
​            return new User(id,"错误1");
​        }

​        @Override
​        public List<User> findAll() {
​            return null;
​        }
​    };
}

}

4.application.yml/application.properties配置

server:
  port: 9002

eureka:
  client:
    register-with-eureka: false
    service-url:
      defaultZone: http://localhost:7001/eureka

#开启降级
feign:
  hystrix:
    enabled: true

5.运行测试

3.hystrix监控页面

1.新建项目导入依赖

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

​    <dependency>
​        <groupId>org.springframework.cloud</groupId>
​        <artifactId>spring-cloud-starter-netflix-hystrix-dashboard</artifactId>
​    </dependency>

@SpringBootApplication
@EnableHystrixDashboard //开启监控页面
public class HystrixDashboardApplication {
    public static void main(String[] args) {
        SpringApplication.run(HystrixDashboardApplication.class,args);
    }
}

server:
  port: 8767

访问http://localhost:8767/hystrix

2.被监控项目导入依赖

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

feign:
  hystrix:
    enabled: true
management:
  endpoints:
    web:
      exposure:
        include: hystrix.stream

@SpringBootApplication
@EnableEurekaClient //启动eureka客户端
@EnableCircuitBreaker //开启hystrix
public class springcloud_mapper {

    public static void main(String[] args) {
        SpringApplication.run(springcloud_mapper.class);
    }

    @Bean
    public ServletRegistrationBean hystrixMetricsStreamServlet(){
        ServletRegistrationBean servletRegistrationBean = new ServletRegistrationBean(new HystrixMetricsStreamServlet());
        servletRegistrationBean.addUrlMappings("/actuator/hystrix.stream");
        return servletRegistrationBean;
    }

}

3.填写监控路径

3.运行测试

9.springcloud zuul

zuul是Netflix设计用来为所有面向设备、web网站提供服务的所有应用的门面，zuul可以提供动态路由、监控、弹性扩展、安全认证等服务，他还可以根据需求将请求路由到多个应用中。

1.新建项目添加依赖

<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>

2.添加配置

spring:
  application:
    name: springcloud-zuul5001

server:
  port: 80


eureka:
  client:
    service-url:
      defaultZone: http://localhost:7001/eureka
zuul:
  routes:
    myuser.serviceId: SPRINGCLOUD-MAPPER #要映射的eureka服务注册中心的名字
    myuser.path: /abc/** #映射路径
  ignored-services: "*" #拦截所有服务，ignored-services:SPRINGCLOUD-MAPPER拦截SPRINGCLOUD-MAPPER服务，加了这个配置不能再通过http://localhost/s/springcloud-mapper/user/findId/1进行访问,不加则可以
  prefix: /s#前缀

@SpringBootApplication
@EnableZuulProxy #开启网管
public class ZuulApplication5001 {
    public static void main(String[] args) {
        SpringApplication.run(ZuulApplication5001.class,args);
    }
}

3.运行测试

访问http://localhost/s/abc/user/findId/1

来源：CSDN

作者：zuiai-

链接：https://blog.csdn.net/a776968499/article/details/104517319