# example_study

**Repository Path**: zlfmm/example_study

## Basic Information

- **Project Name**: example_study
- **Description**: Spring Cloud框架学习demo代码。
包含了eureka、zuul、ribbon、feign、admin、config server组件及其配置方法
- **Primary Language**: Java
- **License**: Not specified
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2020-07-18
- **Last Updated**: 2021-04-27

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

学习springcloud笔记：


一. 父pom文件的引入<p>
    
    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
        <spring-cloud.version>Edgware.SR3</spring-cloud.version>
        <spring-boot.version>1.5.10.RELEASE</spring-boot.version>
      </properties>
    <dependencyManagement>
        <dependencies>
          <!-- 定义 spring cloud 版本 -->
          <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-dependencies</artifactId>
            <version>${spring-cloud.version}</version>
            <type>pom</type>
            <scope>import</scope>
          </dependency>
          <!-- 定义 springboot 版本 -->
          <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-dependencies</artifactId>
            <version>${spring-boot.version}</version>
            <type>pom</type>
            <scope>import</scope>
          </dependency>
        </dependencies>
      </dependencyManagement>
      
      
二. erueka注册中心<p>

    1. pom引入；
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka-server</artifactId>
        </dependency>
        
    2. 主函数注解；
        @EnableEurekaServer
        
    3. application.yml文件；
        eureka:
          instance:
            hostname: localhost
            ip-address: localhost
          client:
            serviceUrl:
              defaultZone: http://localhost:7001/eureka/
            register-with-eureka: false
            fetch-registry: false

三. eureka集群<p>

    修改application.yml文件（**spring.application.name可不相同**）
    eureka:
      instance:
        hostname: localhost
        ip-address: localhost
      client:
        serviceUrl:
          defaultZone: http://localhost:7002/eureka/,http://localhost:7003/eureka/
        register-with-eureka: false
        fetch-registry: false
        
四. ribbon负载均衡<p>（客户端配置）

    1. pom文件引入
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-ribbon</artifactId>
        </dependency>
        
    2. 主函数配置restTemplate（@SpringBootApplication包含了@Configuration注解）
        @Bean
        @LoadBalanced // 开启rebbon的负载均衡（客户端的软负载均衡）
        public RestTemplate restTemplate(){
            return new RestTemplate();
        }
        
    3.自定义负载均衡规则
        3.1 主函数添加：
            @RibbonClient(name = "study-provider", configuration = RibbonRoleConfig.class)
        
        3.2 新建类RibbonRoleConfig：
            @Configuration
            public class RibbonRoleConfig {
                @Bean
                public IRule ribbonRule(){
                    return new RandomRule();
                }
            }

五. feign负载均衡<p>（客户端配置）

    1. pom文件引入
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-feign</artifactId>
        </dependency>
    
    2. 主函数添加：
        @EnableFeignClients(basePackages = {"com.customer.feign"})
        
    3. 配置接口
        @FeignClient(value = "${feign.provider}")

    4. 自定义负载均衡规则
        @Bean
        @LoadBalanced
        public IRule getRule(){
            return new RandomRule();
        }

六. 服务熔断<p>（服务端配置）
    
    1. pom引入
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-hystrix</artifactId>
        </dependency>
        
    2. 主函数添加：
        @EnableCircuitBreaker
    
    3. 接口类方法添加
        @HystrixCommand(fallbackMethod = "hystrix_demo")
    
    4. 同接口新建hystrix_demo方法
        public String hystrix_demo(){
            return "服务出异常了，这是熔断返回值";
        }
        
    5. 访问 http://localhost:8081/feign.stream
    
七. 服务降级<p>（客户端配置）在feign基础上
    
    1. yml文件修改配置
       feign:
         hystrix:
           enabled: true

    2. 接口类修改
        @FeignClient(value = "${feign.provider}", fallbackFactory = MyFallBackFactory.class)
    
    3. 新建类MyFallBackFactory
        @Component
        public class MyFallBackFactory implements FallbackFactory<TestFeignService> {
            @Override
            public TestFeignService create(Throwable cause) {
                return new TestFeignService() {
                    @Override
                    public String getDemo() {
                        return "这里是服务降级~~生产者挂掉了！！！";
                    }
                };
            }
        }
        
八. 熔断服务监控<p>

    1. pom引入
        <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>
       
    2. 主函数添加
        @EnableHystrixDashboard
        
    3. 访问 http://localhost:9001/hystrix
    
九. zuul网关<p>

    1. pom引入
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-zuul</artifactId>
        </dependency>
    
    2. 主函数添加
        @EnableZuulProxy
        
    3. yml文件添加
        zuul:
          routes:
            my.serviceId: study-provider
            my.path: /my/**
          ignored-services: "*" #屏蔽原路由 http://localhost:9527/study-provider/demo, 使用 http://localhost:9527/my/demo
          prefix: /api    # 统一添加前缀 http://localhost:9527/api/my/demo

十. 配置中心服务端<p>连接远程仓库
    
    1. pom文件引入
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-config-server</artifactId>
        </dependency>
        <!--解决git插件报的异常-->
        <dependency>
            <groupId>org.eclipse.jgit</groupId>
            <artifactId>org.eclipse.jgit</artifactId>
            <version>4.8.0.201706111038-r</version>
        </dependency>
        
    2. 主函数添加
        @EnableConfigServer
    
    3. yml文件添加
        spring:
          application:
            name: study-config
          cloud:
            config:
              server:
                git:
                  uri: git@gitee.com:zlfmm/example_study_config.git
    
    4. gitee创建example_study_config远程仓库
        4.1 提交文件application.yml文件
            spring:
              profiles: 
                active: 
                - dev
            ---
            spring:
              profiles: dev
              application: 
                name: study-config-dev
            ---
            spring:
              profiles: test
              application: 
                name: study-config-test
        4.2 访问 http://localhost:9999/application-dev.yml

十一. 配置中心客户端<p>配置服务地址，从而从远程仓库取配置数据
    
    1. pom文件引入
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-config</artifactId>
        </dependency>
        
    2. 主函数添加
        @EnableEurekaClient
    
    3. 新建bootstrap.yml文件
        spring:
          cloud:
            config:
              name: study-config-client #需要从gitee上读取的资源名称，注意没有yml后缀名
              profile: test  #本次访问的配置项
              label: master
              uri: http://localhost:9999  # 本微服务启动后先去找9999号服务，通过SpringCloudConfig获取Gitee的服务地址
    
    4. 新建application.yml文件
        spring:
          application:
            name: study-config-client