SpringCloud基礎+基本框架

• 2019 年 12 月 27 日
• 筆記

SpringCloud極大的簡化了分散式系統的開發，實現了微服務的快速部署和靈活應用

SpringCloud主要框架

* 服務發現–Netfix Eureka

* 服務調用–Netfix Feign

* 熔斷器–Netfix Hystrix

* 服務網關–Netfix Zuul

* 分散式配置–Spring Cloud Config

* 消息匯流排–Spring Cloud Bus

注意SpringCloud和SpringBoot版本要一一對應，不然會報錯

一。Eureka服務發現

外部的pom.xml

<?xml version="1.0" encoding="UTF-8"?>  <project xmlns="http://maven.apache.org/POM/4.0.0"           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"           xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">      <modelVersion>4.0.0</modelVersion>      <packaging>pom</packaging>      <modules>          <module>tensquare_eureka</module>      </modules>        <parent>          <groupId>org.springframework.boot</groupId>          <artifactId>spring-boot-starter-parent</artifactId>          <version>2.0.3.RELEASE</version>      </parent>        <groupId>com.jinke</groupId>      <artifactId>springboot</artifactId>      <version>1.0-SNAPSHOT</version>        <dependencyManagement>          <dependencies>              <dependency>                  <groupId>org.springframework.cloud</groupId>                  <artifactId>spring-cloud-dependencies</artifactId>                  <version>Finchley.RELEASE</version>                  <type>pom</type>                  <scope>import</scope>              </dependency>          </dependencies>      </dependencyManagement>      <dependencies>          <dependency>              <groupId>org.springframework.boot</groupId>              <artifactId>spring-boot-starter-web</artifactId>              <version>2.0.3.RELEASE</version>          </dependency>            <dependency>              <groupId>org.springframework.boot</groupId>              <artifactId>spring-boot-devtools</artifactId>          </dependency>      </dependencies>    </project>

內部的pom.xml

<?xml version="1.0" encoding="UTF-8"?>  <project xmlns="http://maven.apache.org/POM/4.0.0"           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"           xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">      <parent>          <artifactId>springboot</artifactId>          <groupId>com.jinke</groupId>          <version>1.0-SNAPSHOT</version>      </parent>      <modelVersion>4.0.0</modelVersion>        <artifactId>tensquare_eureka</artifactId>        <dependencies>          <dependency>              <groupId>org.springframework.cloud</groupId>              <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>              <version>2.1.2.RELEASE</version>          </dependency>      </dependencies>    </project>

application.yml

server:    port: 6868  eureka:    client:      register-with-eureka: false      fetch-registery: false      service-url:        defaultZone: http://127.0.0.1:${server.port}/eureka/

EurekaServer.java

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

直接啟動看

二。Eureka服務註冊

新建一個module

在pom.xml中增加

<dependency>      <groupId>org.springframework.cloud</groupId>      <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>      <version>2.1.2.RELEASE</version>  </dependency>

application.yml

server:    port: 9004  spring:    application:      name: register  eureka:    client:      service-url:        defaultZone: http://127.0.0.1:6868/eureka/    instance:      prefer-ip-address: true

RegisterApplication.java

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

applicaiton跑起來，看結果已經註冊成功了

三。服務調用

被調register的LabelController

package com.example.register.controller;    import org.springframework.web.bind.annotation.*;    @RestController  @RequestMapping("/label")  @CrossOrigin  public class LabelController {        @RequestMapping(value = "/{labelId}", method = RequestMethod.GET)      public String findById(@PathVariable("labelId") String id) {          System.out.println("調用成功");          return "success";      }    }

主調register2的ProblerController

package com.example.register2.controller;    import com.example.register2.client.BaseClient;  import org.springframework.beans.factory.annotation.Autowired;  import org.springframework.web.bind.annotation.*;    @RestController  @CrossOrigin  @RequestMapping("/problem")  public class ProblemController {      @Autowired      private BaseClient baseClient;        @RequestMapping(value = "/label/{labelId}", method = RequestMethod.GET)      public String findByLabelId(@PathVariable String labelId) {          baseClient.findById(labelId);          return "success";      }  }

application

package com.example.register2;    import org.springframework.boot.SpringApplication;  import org.springframework.boot.autoconfigure.SpringBootApplication;  import org.springframework.cloud.client.discovery.EnableDiscoveryClient;  import org.springframework.cloud.netflix.eureka.EnableEurekaClient;  import org.springframework.cloud.openfeign.EnableFeignClients;    @SpringBootApplication  @EnableEurekaClient  @EnableDiscoveryClient  @EnableFeignClients  public class Register2Application {        public static void main(String[] args) {          SpringApplication.run(Register2Application.class, args);      }    }

BaseClient

package com.example.register2.client;    import org.springframework.cloud.openfeign.FeignClient;  import org.springframework.web.bind.annotation.PathVariable;  import org.springframework.web.bind.annotation.RequestMapping;  import org.springframework.web.bind.annotation.RequestMethod;    @FeignClient("register")  public interface BaseClient {        @RequestMapping(value = "/label/{labelId}", method = RequestMethod.GET)      public String findById(@PathVariable("labelId") String labelId);  }

eureka和register、register2服務都分別跑起來

同時可以看到register的控制台輸出了「調用成功」，即代表調用其他服務成功

Spring已經實現了負載均衡，即調用服務集群時，會公平的輪流調用其中的服務

四。熔斷器

熔斷器可以有效避免雪崩現象

當被調服務掛掉以後，會走熔斷器裡面的內容

調用的服務增加實現類

package com.example.register2.client.impl;    import com.example.register2.client.BaseClient;  import org.springframework.stereotype.Component;    @Component  public class BaseClientImpl implements BaseClient {      @Override      public String findById(String labelId) {          System.out.println("熔斷器觸發了");          return "success";      }  }

application.yml增加

feign:    hystrix:      enabled: true

五。網關

網關的作用就相當於一個中轉分發站，介面

新建一個網關

pom.xml

<?xml version="1.0" encoding="UTF-8"?>  <project xmlns="http://maven.apache.org/POM/4.0.0"           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"           xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">      <parent>          <artifactId>springboot</artifactId>          <groupId>com.jinke</groupId>          <version>1.0-SNAPSHOT</version>      </parent>      <modelVersion>4.0.0</modelVersion>        <artifactId>manager</artifactId>        <dependencies>          <dependency>              <groupId>org.springframework.cloud</groupId>              <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>              <version>2.1.2.RELEASE</version>          </dependency>          <dependency>              <groupId>org.springframework.cloud</groupId>              <artifactId>spring-cloud-starter-netflix-zuul</artifactId>              <version>2.1.2.RELEASE</version>          </dependency>      </dependencies>    </project>

application.yml

server:    port: 9011  spring:    application:      name: manager  eureka:    client:      service-url:        defaultZone: http://127.0.0.1:6868/eureka/    instance:      prefer-ip-address: true  zuul:    routes:      register:        path: /register/**        serviceId: register

application

package com.jinke.manager;    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;    @SpringBootApplication  @EnableEurekaClient  @EnableZuulProxy  public class ManagerApplication {      public static void main(String[] args) {          SpringApplication.run(ManagerApplication.class);      }  }

然後啟動服務即可

六。網關過濾

在網關模組新建一個過濾類即可

package com.jinke.manager.filter;    import com.netflix.zuul.ZuulFilter;  import com.netflix.zuul.exception.ZuulException;  import org.springframework.stereotype.Component;    @Component  public class ManagerFilter extends ZuulFilter {      @Override      public String filterType() {          //過濾器類型：之前或之後          return "pre";      }        @Override      public int filterOrder() {          //多個過濾器的執行順序          return 0;      }        @Override      public boolean shouldFilter() {          //是否開啟該過濾器          return true;      }        @Override      public Object run() throws ZuulException {          //如果設置setsendzullResponse(false)表示不再繼續執行          System.out.println("已經執行到最後了");          return null;      }  }

七。SpringCloudConfig配置

新建config的module

pom.xml

<?xml version="1.0" encoding="UTF-8"?>  <project xmlns="http://maven.apache.org/POM/4.0.0"           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"           xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">      <parent>          <artifactId>springboot</artifactId>          <groupId>com.jinke</groupId>          <version>1.0-SNAPSHOT</version>      </parent>      <modelVersion>4.0.0</modelVersion>        <artifactId>config</artifactId>      <dependencies>          <dependency>              <groupId>org.springframework.cloud</groupId>              <artifactId>spring-cloud-config-server</artifactId>              <version>2.1.3.RELEASE</version>          </dependency>      </dependencies>  </project>

application.xml

server:    port: 12000  spring:    application:      name: config    cloud:      config:        server:          git:            uri: https://gitee.com/king1039/springcloud-config.git            username: [email protected]            password: xxxxxx

application

package com.jinke.config;    import org.springframework.boot.SpringApplication;  import org.springframework.boot.autoconfigure.SpringBootApplication;  import org.springframework.cloud.config.server.EnableConfigServer;    @SpringBootApplication  @EnableConfigServer  public class ConfigApplication {      public static void main(String[] args) {          SpringApplication.run(ConfigApplication.class);      }  }

服務跑起來，如果提示Authentication is required but no CredentialsProvider has been registered是因為要帳號密碼驗證，在配置文件填上

在git上修改以後，刷新會得到新的結果

下面通過配置來調用服務

新建一個base的module

bootstrap.myl

spring:    cloud:      config:        name: springcloud        profile: config        label: master        uri: http://127.0.0.1:12000

git上的配置文件springcloud-config.yml

server:    port: 9001  spring:    application:      name: base  eureka:    client:      service-url:          defaultZone: http://127.0.0.1:6868/eureka/    instance:      prefer-ip-address: true

開啟eureka、config、base三個服務，然後調用

流程就是先讀取Git上的配置，然後拉下來，再調用服務

下面來通過bus消息開啟監聽

config的配置文件application.yml

server:    port: 12000  spring:    application:      name: config    cloud:      config:        server:          git:            uri: https://gitee.com/king1039/springcloud-config.git            username: ********@qq.com            password: ******    rabbitmq:      host: ***.***.***.***  management:    endpoints:      web:        exposure:          include: bus-refresh

被調的服務配置文件

server:    port: 9001  spring:    application:      name: base    rabbitmq:      host: ***.***.***.***  eureka:    client:      service-url:          defaultZone: http://127.0.0.1:6868/eureka/    instance:      prefer-ip-address: true

修改了被調配置文件後，使用post請求發送一次bus-refresh即可實現消息傳遞

如果要監聽自定義的標籤需要增加註解@RefreshScope

程式碼地址：https://github.com/king1039/SpringCloud.git

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