微服务-注册中心、配置中心、网关

image.png

组件选择

参考：官方

注册中心：SpringCloud Alibaba Nacos
配置中心：SpringCloud Alibaba Nacos
负载均衡：SpringCloud Ribbon
声明式HTTP客户端：SpringCloud Feign ——调用远程服务
负载均衡：SpringCloud Ribbon —— feign中已经整合，无需显示引用
服务容错：SpringCloud Alibaba Sentinel ——限流、降级、熔断
API网关：SpringCloud Gateway ——webflux 编程模式
调用链路监控：SpringCloud Sleuth
分布式事务：SpringCloud Alibaba Seata ——原Fescar

下载 Nacos Server

下载地址：Github Release 由上面版本选择可知：当前对应 Nacos 版本为1.2.1

下载对应系统的tar包(Linux)或者zip包(Windows)，解压后运行bin目录下的可执行文件即可运行Nacos

引入Nacos作为注册中心

1. pom文件引入依赖

  • common模块 ```xml <?xml version=”1.0” encoding=”UTF-8”?> <project xmlns=”http://maven.apache.org/POM/4.0.0“

    1.    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    2.    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

    1.   <artifactId>mall</artifactId>
    2.   <groupId>groupId</groupId>
    3.   <version>1.0-SNAPSHOT</version>

    4.0.0

    mall-common

    每一个微服务公共的依赖，bean，工具类等 

    1.   <!--        mybatis-plus-->
    2.   <dependency>
    3.       <groupId>com.baomidou</groupId>
    4.       <artifactId>mybatis-plus-boot-starter</artifactId>
    5.       <version>3.2.0</version>
    6.   </dependency>
    8.   <dependency>
    9.       <groupId>org.projectlombok</groupId>
    10.       <artifactId>lombok</artifactId>
    11.       <version>1.18.8</version>
    12.   </dependency>
    14.   <!-- https://mvnrepository.com/artifact/org.apache.httpcomponents/httpcore -->
    15.   <dependency>
    16.       <groupId>org.apache.httpcomponents</groupId>
    17.       <artifactId>httpcore</artifactId>
    18.       <version>4.4.12</version>
    19.   </dependency>
  1.     <dependency>
  2.         <groupId>commons-lang</groupId>
  3.         <artifactId>commons-lang</artifactId>
  4.         <version>2.6</version>
  5.     </dependency>
  7.     <!--    导入mysql驱动    -->
  8.     <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
  9.     <dependency>
  10.         <groupId>mysql</groupId>
  11.         <artifactId>mysql-connector-java</artifactId>
  12.         <version>8.0.17</version>
  13.     </dependency>
  15.     <dependency>
  16.         <groupId>javax.servlet</groupId>
  17.         <artifactId>servlet-api</artifactId>
  18.         <version>2.5</version>
  19.         <scope>provided</scope>
  20.     </dependency>
  22.     <!--        服务注册/发现-->
  23.     <dependency>
  24.         <groupId>com.alibaba.cloud</groupId>
  25.         <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
  26.     </dependency>
  28.     <dependency>
  29.         <groupId>javax.validation</groupId>
  30.         <artifactId>validation-api</artifactId>
  31.         <version>2.0.1.Final</version>
  32.     </dependency>
  34.     <dependency>
  35.         <groupId>org.slf4j</groupId>
  36.         <artifactId>slf4j-api</artifactId>
  37.         <version>1.7.32</version>
  38.     </dependency>
  39.     <dependency>
  40.         <groupId>org.springframework.boot</groupId>
  41.         <artifactId>spring-boot-test</artifactId>
  42.         <version>2.1.8.RELEASE</version>
  43.         <scope>test</scope>
  44.     </dependency>
  45.     <dependency>
  46.         <groupId>junit</groupId>
  47.         <artifactId>junit</artifactId>
  48.         <version>4.13.2</version>
  49.         <scope>test</scope>
  50.     </dependency>
  51.     <dependency>
  52.         <groupId>org.junit.jupiter</groupId>
  53.         <artifactId>junit-jupiter-api</artifactId>
  54.         <version>5.8.0-M1</version>
  55.         <scope>test</scope>
  56.     </dependency>
  57.     <!--        配置中心来做配置管理-->
  58.     <dependency>
  59.         <groupId>com.alibaba.cloud</groupId>
  60.         <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
  61.     </dependency>
  62. </dependencies>
  64. <dependencyManagement>
  65.     <dependencies>
  66.         <dependency>
  67.             <groupId>com.alibaba.cloud</groupId>
  68.             <artifactId>spring-cloud-alibaba-dependencies</artifactId>
  69.             <version>2.1.0.RELEASE</version>
  70.             <type>pom</type>
  71.             <scope>import</scope>
  72.         </dependency>
  74.     </dependencies>
  75. </dependencyManagement>

  2. - coupon模块
  3. ```xml
  4. <?xml version="1.0" encoding="UTF-8"?>
  5. <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  6.          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
  7.     <modelVersion>4.0.0</modelVersion>
  8.     <parent>
  9.         <groupId>org.springframework.boot</groupId>
  10.         <artifactId>spring-boot-starter-parent</artifactId>
  11.         <version>2.1.8.RELEASE</version>
  12.         <relativePath/> <!-- lookup parent from repository -->
  13.     </parent>
  14.     <groupId>com.ht.mall</groupId>
  15.     <artifactId>gulimall-coupon</artifactId>
  16.     <version>0.0.1-SNAPSHOT</version>
  17.     <name>mall-coupon</name>
  18.     <description>商城-优惠卷服务</description>
  20.     <properties>
  21.         <java.version>1.8</java.version>
  22.         <spring-cloud.version>Greenwich.SR3</spring-cloud.version>
  23.     </properties>
  25.     <dependencies>
  26.         <dependency>
  27.             <groupId>groupId</groupId>
  28.             <artifactId>mall-common</artifactId>
  29.             <version>1.0-SNAPSHOT</version>
  30.         </dependency>
  31.         <dependency>
  32.             <groupId>org.springframework.boot</groupId>
  33.             <artifactId>spring-boot-starter-web</artifactId>
  34.         </dependency>
  35.         <dependency>
  36.             <groupId>org.springframework.cloud</groupId>
  37.             <artifactId>spring-cloud-starter-openfeign</artifactId>
  38.         </dependency>
  40.         <dependency>
  41.             <groupId>org.springframework.boot</groupId>
  42.             <artifactId>spring-boot-starter-test</artifactId>
  43.             <scope>test</scope>
  44.         </dependency>
  45.         <dependency>
  46.             <groupId>org.junit.jupiter</groupId>
  47.             <artifactId>junit-jupiter-api</artifactId>
  48.             <version>5.8.0-M1</version>
  49.             <scope>test</scope>
  50.         </dependency>
  51.     </dependencies>
  53.     <dependencyManagement>
  54.         <dependencies>
  55.             <dependency>
  56.                 <groupId>org.springframework.cloud</groupId>
  57.                 <artifactId>spring-cloud-dependencies</artifactId>
  58.                 <version>${spring-cloud.version}</version>
  59.                 <type>pom</type>
  60.                 <scope>import</scope>
  61.             </dependency>
  62.         </dependencies>
  63.     </dependencyManagement>
  65.     <build>
  66.         <plugins>
  67.             <plugin>
  68.                 <groupId>org.springframework.boot</groupId>
  69.                 <artifactId>spring-boot-maven-plugin</artifactId>
  70.             </plugin>
  71.         </plugins>
  72.     </build>
  74. </project>

2. yaml文件增加配置

在 coupon 中的application.yml 配置文件中配置 Nacos Server 地址和微服务名称

  1. spring:
  2.   application:
  3.     name: mall-coupon
  4.   datasource:
  5.     driver-class-name: com.mysql.cj.jdbc.Driver
  6.     url: jdbc:mysql://192.168.1.103:3306/mall_sms?useUnicode=true&characterEncoding=UTF-8&useSSL=false&serverTimezone=Asia/Shanghai
  7.     username: root
  8.     password: root
  9.   cloud:
  10.     nacos:
  11.       discovery:
  12.         server-addr: localhost:8848
  14. mybatis-plus:
  15.   mapper-locations: classpath:/mapper/**/*.xml
  16.   global-config:
  17.     db-config:
  18.       id-type: auto
  20. server:
  21.   port: 7000

3. 主启动类增加注解

使用 @EnableDiscoveryClient 注解开启服务注册与发现功能

  1. @MapperScan("com.ht.mall.product.dao")
  2. @SpringBootApplication
  3. @EnableDiscoveryClient
  4. public class MallCouponApplication {
  5.     public static void main(String[] args) {
  6.         SpringApplication.run(MallCouponApplication.class, args);
  7.     }
  8. }

此时，启动Nacos，运行主启动类启动服务后，在浏览器打开配置文件中的地址：localhost:8848/nacos (账号密码：nacos/nacos)中就可以看到当前服务已经注册到 Nacos 服务列表中

其他服务以同样方式配置即可

引入Feign远程服务调用

测试member和coupon的远程调用

想要获取当前会员领取到的所有优惠券。先去注册中心找优惠券服务， 注册中心调一台优惠券服务器给会员，会员服务器发送请求给这台优 惠券服务器，然后对方响应。

Feign与注册中心
spring cloud feign

声明式远程调用

feign是一个声明式的HTTP客户端，他的目的就是让远程调用更加简单。
给远程服务发的是HTTP请求。

  1. 会员服务想要远程调用优惠券服务，只需要给会员服务里引入openfeign依赖，他就有了远程调用其他服务的能力。

    1. <dependency>
    2.  <groupId>org.springframework.cloud</groupId>
    3.  <artifactId>spring-cloud-starter-openfeign</artifactId>
    4. </dependency>

  2. 在coupon中修改如下的内容

    1. @RequestMapping("coupon/coupon")
    2. public class CouponController {
    3.  @Autowired
    4.  private CouponService couponService;
    6.  @RequestMapping("/member/list")
    7.  public R membercoupons(){    //全系统的所有返回都返回R
    8.      // 应该去数据库查用户对于的优惠券，但这个我们简化了，不去数据库查了，构造了一个优惠券给他返回
    9.      CouponEntity couponEntity = new CouponEntity();
    10.      couponEntity.setCouponName("满100减10");//优惠券的名字
    11.      return R.ok().put("coupons",Arrays.asList(couponEntity));
    12.  }

  3. 这样我们准备好了优惠券的调用内容 在member的配置类上加注解@EnableFeignClients(basePackages=”com.ht.mall.member.feign”)， 告诉spring这里面是一个远程调用客户端，member要调用的接口

    1. @SpringBootApplication
    2. @EnableDiscoveryClient
    3. @EnableFeignClients(basePackages="com.ht.mall.member.feign")
    4. public class MallMemberApplication {
    6.  public static void main(String[] args) {
    7.      SpringApplication.run(MallMemberApplication    .class, args);
    8.  }
    9. }

  4. 调用刚才写的优惠券的功能

复制函数部分，在member的com.ht.mall.member.feign包下新建接口：

  1. /**
  2.  * 告诉spring cloud这个接口是一个远程客户端
  3.  */
  4. @FeignClient("mall-coupon")
  5. public interface CouponFeignService {
  6.     /**
  7.      * 调用coupon服务，再去调用coupon服务/coupon/coupon/member/list对应的方法
  8.      * @return 得到一个R对象
  9.      */
  10.     @RequestMapping("/coupon/coupon/member/list")
  11.     public R memberCoupons();
  12. }

  1. 然后我们在member的控制层写一个测试请求

    1. @RestController
    2. @RequestMapping("member/member")
    3. public class MemberController {
    4.  @Autowired
    5.  private MemberService memberService;
    7.  @Autowired
    8.  CouponFeignService couponFeignService;
    10.     @RequestMapping("/coupons")
    11.  public R test() {
    12.      MemberEntity memberEntity = new MemberEntity();
    13.      memberEntity.setNickname("张三");
    14.      // 假设张三去数据库查了后返回了张三的优惠券信息
    15.      R memberCoupons = couponFeignService.memberCoupons();
    16.      // 打印会员和优惠券信息
    17.      return R.ok().put("member", memberEntity).put("coupons", memberCoupons.get("coupons"));
    18.  }
    20.     ......
    21. }

  2. 重新启动服务

http://localhost:8000/member/member/coupons

  1. {"msg":"success","code":0,"coupons":[{"id":null,"couponType":null,"couponImg":null,"couponName":"满100减10","num":null,"amount":null,"perLimit":null,"minPoint":null,"startTime":null,"endTime":null,"useType":null,"note":null,"publishCount":null,"useCount":null,"receiveCount":null,"enableStartTime":null,"enableEndTime":null,"code":null,"memberLevel":null,"publish":null}],"member":{"id":null,"levelId":null,"username":null,"password":null,"nickname":"张三","mobile":null,"email":null,"header":null,"gender":null,"birth":null,"city":null,"job":null,"sign":null,"sourceType":null,"integration":null,"growth":null,"status":null,"createTime":null}}

引入Nacos作为配置中心

参考：官方介绍

1. common模块引入nacos-config依赖

  1. <dependency>
  2.      <groupId>com.alibaba.cloud</groupId>
  3.      <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
  4.  </dependency>

2. 配置 Nacos Config 元数据

在服务模块新建bootstrap.properties
此处以coupon服务为例：

  1. spring.application.name=mall-coupon
  2. spring.cloud.nacos.config.server-addr=localhost:8848

3. 测试读取配置中心配置

给配置中心新增一个配置
image.png
读取配置
application.properties

  1. coupon.user.name=zhangsan2
  2. coupon.user.age=20

CouponController.java
@RefreseScope：动态刷新，修改配置中心配置不需要重新启动项目

  1. @RefreshScope
  2. @RestController
  3. @RequestMapping("coupon/coupon")
  4. public class CouponController {
  5.     @Autowired
  6.     private CouponService couponService;
  8.     @Value("${coupon.user.name}")
  9.     private String name;
  10.     @Value("${coupon.user.age}")
  11.     private Integer age;
  13.     @RequestMapping("/test")
  14.     public R test() {
  15.         return R.ok().put("name", name).put("age", age);
  16.     }
  17. }

请求 /coupon/coupon/test 可以看到配置中心的数据，修改配置中心的配置，刷新可自动更新，nacos的配置内容优先于项目本地的配置内容。

4. Nacos 命名空间

为了对不同服务之间进行配置隔离，这里为每个微服务创建自己的命名空间。
image.png
后端代码中在 bootstrap.properties 配置属于自己服务的命名空间

  1. spring.application.name=mall-coupon
  2. spring.cloud.nacos.config.server-addr=localhost:8848
  3. spring.cloud.nacos.config.namespace=eed1d158-6019-487f-b38a-cf79430eba44

5. 加载多配置集

  • 配置集：一组相关或不相关配置项的集合。
  • 配置集ID：类似于配置文件名，即Data ID
  • 配置分组：默认所有的配置集都属于DEFAULT_GROUP。自己可以创建分组，比如双十一，618，双十二

spring.cloud.nacos.config.group=DEFAULT_GROUP # 更改配置分组
最终方案：每个微服务创建自己的命名空间，然后使用配置分组区分环境（dev/test/prod）


把原来application.yml里的内容都分文件抽离出去，在nacos里创建好后，指定coupons要导入的配置即可。
image.png

  • datasource.yml

    1. spring:
    2. datasource:
    3.   driver-class-name: com.mysql.cj.jdbc.Driver
    4.   url: jdbc:mysql://192.168.1.103:3306/mall_sms?useUnicode=true&characterEncoding=UTF-8&useSSL=false&serverTimezone=Asia/Shanghai
    5.   username: root
    6.   password: root

  • mybatis.yml

    1. mybatis-plus:
    2. mapper-locations: classpath:/mapper/**/*.xml
    3. global-config:
    4.   db-config:
    5.     id-type: auto

  • other.yml ```yaml spring: application: name: mall-coupon cloud: nacos:

    1. discovery:
    2.   server-addr: localhost:8848

server: port: 7000

  1. 注释application.yml的内容<br />修改coupon里的bootstrap.properties
  2. ```yaml
  3. # 改名字，对应nacos里的配置文件名
  4. spring.application.name=mall-coupon
  5. spring.cloud.nacos.config.server-addr=localhost:8848
  6. # 可以选择对应的命名空间 ，即写上对应环境的命名空间ID
  7. spring.cloud.nacos.config.namespace=eed1d158-6019-487f-b38a-cf79430eba44
  8. # 配置文件所在的组
  9. spring.cloud.nacos.config.group=dev
  11. # 加载多配置集
  12. spring.cloud.nacos.config.ext-config[0].data-id=datasource.yml
  13. spring.cloud.nacos.config.ext-config[0].group=dev
  14. spring.cloud.nacos.config.ext-config[0].refresh=true
  16. spring.cloud.nacos.config.ext-config[1].data-id=mybatis.yml
  17. spring.cloud.nacos.config.ext-config[1].group=dev
  18. spring.cloud.nacos.config.ext-config[1].refresh=true
  20. spring.cloud.nacos.config.ext-config[2].data-id=other.yml
  21. spring.cloud.nacos.config.ext-config[2].group=dev
  22. spring.cloud.nacos.config.ext-config[2].refresh=true

引入Gateway作为API网关

参考：官网

创建网关子模块mall-gateway

pom.xml

  1. <?xml version="1.0" encoding="UTF-8"?>
  2. <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  3.          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
  4.     <modelVersion>4.0.0</modelVersion>
  5.     <parent>
  6.         <groupId>org.springframework.boot</groupId>
  7.         <artifactId>spring-boot-starter-parent</artifactId>
  8.         <version>2.1.8.RELEASE</version>
  9.         <relativePath/> <!-- lookup parent from repository -->
  10.     </parent>
  11.     <groupId>com.ht.mall</groupId>
  12.     <artifactId>mall-gateway</artifactId>
  13.     <version>0.0.1-SNAPSHOT</version>
  14.     <name>mall-gateway</name>
  15.     <description>API网关</description>
  16.     <properties>
  17.         <java.version>1.8</java.version>
  18.         <spring-cloud.version>Greenwich.SR3</spring-cloud.version>
  19.     </properties>
  20.     <dependencies>
  21.         <dependency>
  22.             <groupId>groupId</groupId>
  23.             <artifactId>mall-common</artifactId>
  24.             <version>1.0-SNAPSHOT</version>
  25.         </dependency>
  26.         <dependency>
  27.             <groupId>org.springframework.cloud</groupId>
  28.             <artifactId>spring-cloud-starter-gateway</artifactId>
  29.             <version>2.1.0.RELEASE</version>
  30.         </dependency>
  31.         <dependency>
  32.             <groupId>org.springframework.boot</groupId>
  33.             <artifactId>spring-boot-starter</artifactId>
  34.         </dependency>
  36.         <dependency>
  37.             <groupId>org.springframework.boot</groupId>
  38.             <artifactId>spring-boot-starter-test</artifactId>
  39.             <scope>test</scope>
  40.         </dependency>
  41.     </dependencies>
  43.     <build>
  44.         <plugins>
  45.             <plugin>
  46.                 <groupId>org.springframework.boot</groupId>
  47.                 <artifactId>spring-boot-maven-plugin</artifactId>
  48.             </plugin>
  49.         </plugins>
  50.     </build>
  52. </project>

主启动类

  1. @EnableDiscoveryClient
  2. @SpringBootApplication(exclude = {DataSourceAutoConfiguration.class})
  3. public class MallGatewayApplication {
  4.     public static void main(String[] args) {
  5.         SpringApplication.run(MallGatewayApplication.class, args);
  6.     }
  7. }

配置nacos注册中心地址applicaion.properties

  1. spring.application.name=mall-gateway
  2. spring.cloud.nacos.discovery.server-addr=localhost:8848
  3. server.port=88

bootstrap.properties 填写配置中心地址

  1. spring.application.name=mall-gateway
  2. spring.cloud.nacos.config.server-addr=localhost:8848
  4. spring.cloud.nacos.config.namespace=cfc9231c-e4d3-4f2e-ad7a-c12faffbf7dc

在gateway命名空间里创建文件mall-gateway.yml

  1. spring:
  2.     application:
  3.         name: mall-gateway

在项目里创建application.yml

  1. spring:
  2.   cloud:
  3.     gateway:
  4.       routes:
  5.         #Query A 参数有A就行，Query B,C 参数B的值为C即可
  6.         #实现针对于“http://localhost:88/hello?url=baidu”，转发到“https://www.baidu.com/hello”，
  7.         #针对于“http://localhost:88/hello?url=qq”的请求，转发到“https://www.qq.com/hello”
  8.         - id: baidu_route
  9.           uri: http://www.baidu.com
  10.           predicates:
  11.             - Query=url,baidu
  13.         - id: test_route
  14.           uri: http://www.qq.com
  15.           predicates:
  16.             - Query=url,qq

测试：

启动项目分别请求：
localhost:88?url=baidu
localhost:88?url=qq
会分别跳转到百度和github 表示成功。