spring-cloud学习

章节统计
1.RestTemplate
2.eureka server,eureka client
3.ribbon的基本使用
4.ribbon自定义负载均衡
5.使用配置文件自定义 Ribbon Client6.Ribbon脱离Eureka使用
7.Feign的简介及基础使用

 容错处理方法是:断路器，超时

单体架构缺点：
1.复杂性逐渐变高
2.技术债务增加
3.部署速度逐渐变慢
4.阻碍创新
5.无法按需伸缩
微服务：


特性：
1.每个微服务可独立运行在自己的进程里
2.一系列独立运行的服务共同构建起了整个系统
3.每个服务为独立开发，一个微服务一般完成某个特定的功能，比如：订单管理，用户管理等。
4.微服务之间通过一些轻量的通信机制进行通信，例如通过REST API或者RPC的方法进行调用。


微服务设计原则
1.单一职责原则
2.服务自制原则
3.轻量级通讯原则
4.接口明确原则


微服务开发框架浅谈

spring cloud 

dubbo 

dropwizard

Angle SR6
地名 Server release:bug修复


spring cloud特点
1.约定优于配置
2.开箱即用，快速启动
3.适用与各种环境
4.轻量级的组件
5.组件的支持很丰富，功能很齐全
6.选项中文


一个maven项目转成gradle项目，运行命令:maven -gradle gradle init -type pom



学习开发 适用的软件版本
1.jdk1.8
2.maven3.3.9
3.IDE( 1,Spring Tool Suite 3.8.2 
2,IDEA)
4.Spring Boot 1.4.1
5.Spring Cloud Camden SR1


04 服务提供者与服务消费者

生成项目，把项目导入eclipse下面

项目microservice-simple-provider-user是服务提供者，

知识点:

1.RestTemplate

org.springframework.web.client.RestTemplate

return restTemplate.getForObject("http://localhost:7900/simple/" + id, User.class);//调用服务提供者提供的链接,此处的链接可以优化 

2.eureka server,eureka client

eureka server项目

pom.xml

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

Application.java

package com.itmuch.cloud;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

security:  basic:    enabled: true #验证  user:    name: user #用户名    password: password123 #密码server:  port: 8761 #端口号eureka:  client:    register-with-eureka: false #表示是否将自己注册到Eureka Server,默认为true    fetch-registry: false #表示是否从eureka服务器获取注册信息    service-url:      defaultZone: http://user:password123@localhost:8761/eureka #配置eureka服务地址

eureka client项目

pom.xml

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

application.yml

server:  port: 7900spring:  jpa:    generate-ddl: false    show-sql: true    hibernate:      ddl-auto: none  datasource:    platform: h2    schema: classpath:schema.sql    data: classpath:data.sql  application:    name: microservice-provider-user # 指定应用的名称logging:  level:    root: INFO    org.hibernate: INFO    org.hibernate.type.descriptor.sql.BasicBinder: TRACE    org.hibernate.type.descriptor.sql.BasicExtractor: TRACE    com.itmuch: DEBUGeureka:  client:    healthcheck:      enabled: true #健康检查    serviceUrl:      defaultZone: http://user:password123@localhost:8761/eureka  instance:    prefer-ip-address: true #表示使用IP进行配置    instance-id: ${spring.application.name}:${spring.cloud.client.ipAddress}:${spring.application.instance_id:${server.port}}    metadata-map:      zone: ABC      # eureka可以理解的元数据      lilizhou: BBC  # 不会影响客户端行为    lease-renewal-interval-in-seconds: 5

Application.java

@EnableEurekaClient

3.ribbon的基本使用

ribbon 客户端的负载均衡

pom包 group org.springframework.cloud and artifact id spring-cloud-starter-netflix-ribbon，如果引入了eureka包，这个包就不用再引入了。

4.ribbon自定义负载均衡

ribbon调用默认是轮询算法。可以自定义

微博说明http://blog.csdn.net/qwlzxx/article/details/77118634

运行效果

访问地址

http://localhost:8010/test

111:microservice-provider-user:192.168.32.134:7900222:microservice-provider-user2:192.168.32.134:7801111:microservice-provider-user:192.168.32.134:7900222:microservice-provider-user2:192.168.32.134:7800111:microservice-provider-user:192.168.32.134:7900222:microservice-provider-user2:192.168.32.134:7801111:microservice-provider-user:192.168.32.134:7900222:microservice-provider-user2:192.168.32.134:7800111:microservice-provider-user:192.168.32.134:7900222:microservice-provider-user2:192.168.32.134:7801111:microservice-provider-user:192.168.32.134:7901222:microservice-provider-user2:192.168.32.134:7800111:microservice-provider-user:192.168.32.134:7900222:microservice-provider-user2:192.168.32.134:7801111:microservice-provider-user:192.168.32.134:7901222:microservice-provider-user2:192.168.32.134:7800111:microservice-provider-user:192.168.32.134:7901222:microservice-provider-user2:192.168.32.134:7801111:microservice-provider-user:192.168.32.134:7900222:microservice-provider-user2:192.168.32.134:7800111:microservice-provider-user:192.168.32.134:7900222:microservice-provider-user2:192.168.32.134:7801

得出结果，

microservice-provider-user端口号是随机的，所以负载均衡算法是随机的

microservice-provider-user2端口号是轮询的，所以负载均衡算法是轮询的。

5. 使用配置文件自定义 Ribbon Client

Customizing the Ribbon Client using properties

application.yml

users:  ribbon:    NIWSServerListClassName: com.netflix.loadbalancer.ConfigurationBasedServerList    NFLoadBalancerRuleClassName: com.netflix.loadbalancer.WeightedResponseTimeRule

6.Ribbon脱离Eureka使用

application.yml

spring:  application:    name: microservice-consumer-movie-ribbonmicroservice-provider-user:  ribbon:    listOfServers: localhost:7900

ribbon调用方: http://localhost:8010/movie/1

===:microservice-provider-user:localhost:7900===:microservice-provider-user:localhost:7900===:microservice-provider-user:localhost:7900===:microservice-provider-user:localhost:7900===:microservice-provider-user:localhost:7900

结果发现全部都是7900

7.Feign的简介及基础使用

Declarative REST Client:Feign

声明试的RestClient

pom.xml

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

feign接口

package com.itmuch.cloud.feign;import org.springframework.cloud.netflix.feign.FeignClient;import org.springframework.web.bind.annotation.PathVariable;import org.springframework.web.bind.annotation.RequestBody;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RequestMethod;import com.itmuch.cloud.entity.User;@FeignClient("microservice-provider-user")public interface UserFeignClient {  @RequestMapping(value = "/simple/{id}", method = RequestMethod.GET)  public User findById(@PathVariable("id") Long id); // 两个坑：1. @GetMapping不支持   2. @PathVariable得设置value  @RequestMapping(value = "/user", method = RequestMethod.POST)  public User postUser(@RequestBody User user);  // 该请求不会成功，只要参数是复杂对象，即使指定了是GET方法，feign依然会以POST方法进行发送请求。可能是我没找到相应的注解或使用方法错误。  // 如勘误，请@lilizhou2008  [e-mail]  @RequestMapping(value = "/get-user", method = RequestMethod.GET)  public User getUser(User user);}