tags: [dubbo, 分布式]
categories: [dubbo]

前言

关于分布式是什么我们为什么要弄分布式这里不赘述，这里只总结一下分布式项目从0搭建的方法和注意事项，本项目各个模块之间调用是基于Dubbo+Zookeeper来实现的

一般情况下我们都是按照服务来切分的，用以各个服务之间的解耦和切分部署，父项目为普通的Maven项目，删掉了源代码文件夹和资源文件夹，只留下光秃秃的pom.xml，来对各个服务依赖进行统筹管理

这里不使用SpringBoot作为父项项目的原因是因为SpringBoot总会继承自父项SpringBoot，子模块必然会继承相关依赖，建立空的Maven项目更加合适

代码地址

https://github.com/bwensun/Embryo/tree/master/BLOG

项目搭建

项目结构

  1. BLOG
  2. ├─ .gitignore
  3. ├─ BLOG_API
  4. │    ├─ BLOG_API.iml
  5. │    ├─ pom.xml
  6. │    ├─ src
  7. │    │    └─ main
  8. │    │           └─ java
  9. ├─ BLOG_USER_SERVICE
  10. │    ├─ BLOG_USER_SERVICE.iml
  11. │    ├─ pom.xml
  12. │    ├─ src
  13. │    │    ├─ main
  14. │    │    │    ├─ java
  15. │    │    │    └─ resources
  16. │    │    └─ test
  17. │    │           └─ java
  18. ├─ BLOG_WEB
  19. │    ├─ BLOG_WEB.iml
  20. │    ├─ pom.xml
  21. │    ├─ src
  22. │    │    └─ main
  23. │    │           ├─ java
  24. │    │           └─ resources
  25. └─ pom.xml

项目建立

建立Maven项目父工程BLOG
正常输入GAV，groupId为项目名，artifactId为倒置的域名，版本号随意，我一般填入1.0，选择默认1.0快照版本也可以的
image.png

这里对项目的依赖做了统筹管理，在父pom中规定了依赖的版本，而子模块中只需写入GA信息即可，这样整个工程的依赖版本更迭时只需要修改父工程的依赖版本即可，另外父pom中也规定了整个项目共用了的依赖，通过依赖传递让子模块自动继承

  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.     <packaging>pom</packaging>
  6.     <modules>
  7.         <module>BLOG_API</module>
  8.         <module>BLOG_USER_SERVICE</module>
  9.         <module>BLOG_WEB</module>
  10.     </modules>
  11.     <parent>
  12.         <groupId>org.springframework.boot</groupId>
  13.         <artifactId>spring-boot-starter-parent</artifactId>
  14.         <version>2.2.2.RELEASE</version>
  15.         <relativePath/> <!-- lookup parent from repository -->
  16.     </parent>
  17.     <groupId>com.bwensun</groupId>
  18.     <artifactId>blog</artifactId>
  19.     <version>0.0.1-SNAPSHOT</version>
  20.     <name>blog</name>
  21.     <description>个人博客项目</description>
  23.     <properties>
  24.         <java.version>1.8</java.version>
  25.         <main.class>com.bwensun.blog.BlogApplication</main.class>
  27.         <!--maven依赖版本控制-->
  28.         <mybatis-spring-boot-starter>1.3.0</mybatis-spring-boot-starter>
  29.         <dubbo-spring-boot-starter>0.2.0</dubbo-spring-boot-starter>
  30.         <mybatis-generator-core>1.3.7</mybatis-generator-core>
  31.         <druid-spring-boot-starter>1.1.10</druid-spring-boot-starter>
  32.         <mysql-connector-java>5.1.44</mysql-connector-java>
  33.         <lombok>1.16.18</lombok>
  34.         <pagehelper>5.1.10</pagehelper>
  35.         <springfox-swagger2>2.6.1</springfox-swagger2>
  36.     </properties>
  38.     <dependencyManagement>
  39.         <dependencies>
  40.             <dependency>
  41.                 <groupId>com.bwensun</groupId>
  42.                 <artifactId>BLOG_API</artifactId>
  43.                 <version>${project.version}</version>
  44.             </dependency>
  45.             <dependency>
  46.                 <groupId>org.mybatis.spring.boot</groupId>
  47.                 <artifactId>mybatis-spring-boot-starter</artifactId>
  48.                 <version>${mybatis-spring-boot-starter}</version>
  49.             </dependency>
  50.             <dependency>
  51.                 <groupId>com.alibaba.boot</groupId>
  52.                 <artifactId>dubbo-spring-boot-starter</artifactId>
  53.                 <version>${dubbo-spring-boot-starter}</version>
  54.             </dependency>
  55.             <dependency>
  56.                 <groupId>org.mybatis.generator</groupId>
  57.                 <artifactId>mybatis-generator-core</artifactId>
  58.                 <version>${mybatis-generator-core}</version>
  59.             </dependency>
  60.             <dependency>
  61.                 <groupId>com.alibaba</groupId>
  62.                 <artifactId>druid-spring-boot-starter</artifactId>
  63.                 <version>${druid-spring-boot-starter}</version>
  64.             </dependency>
  65.             <dependency>
  66.                 <groupId>mysql</groupId>
  67.                 <artifactId>mysql-connector-java</artifactId>
  68.                 <version>${mysql-connector-java}</version>
  69.             </dependency>
  70.         </dependencies>
  71.     </dependencyManagement>
  73.     <!--公有依赖-->
  74.     <dependencies>
  75.         <dependency>
  76.             <groupId>org.springframework.boot</groupId>
  77.             <artifactId>spring-boot-starter</artifactId>
  78.         </dependency>
  79.         <dependency>
  80.             <groupId>org.springframework.boot</groupId>
  81.             <artifactId>spring-boot-starter-test</artifactId>
  82.             <scope>test</scope>
  83.             <exclusions>
  84.                 <exclusion>
  85.                     <groupId>org.junit.vintage</groupId>
  86.                     <artifactId>junit-vintage-engine</artifactId>
  87.                 </exclusion>
  88.             </exclusions>
  89.         </dependency>
  90.         <!--lombok-->
  91.         <dependency>
  92.             <groupId>org.projectlombok</groupId>
  93.             <artifactId>lombok</artifactId>
  94.             <version>${lombok}</version>
  95.         </dependency>
  96.         <dependency>
  97.             <groupId>com.github.pagehelper</groupId>
  98.             <artifactId>pagehelper</artifactId>
  99.             <version>${pagehelper}</version>
  100.         </dependency>
  101.         <!-- swagger2 -->
  102.         <dependency>
  103.             <groupId>io.springfox</groupId>
  104.             <artifactId>springfox-swagger-ui</artifactId>
  105.             <version>${springfox-swagger2}</version>
  106.         </dependency>
  107.         <dependency>
  108.             <groupId>io.springfox</groupId>
  109.             <artifactId>springfox-swagger2</artifactId>
  110.             <version>${springfox-swagger2}</version>
  111.         </dependency>
  112.     </dependencies>
  114.     <build>
  115.         <plugins>
  116.             <plugin>
  117.                 <groupId>org.springframework.boot</groupId>
  118.                 <artifactId>spring-boot-maven-plugin</artifactId>
  119.                 <configuration>
  120.                     <mainClass>${main.class}</mainClass>
  121.                 </configuration>
  122.                 <executions>
  123.                     <execution>
  124.                         <goals>
  125.                             <goal>repackage</goal>
  126.                         </goals>
  127.                     </execution>
  128.                 </executions>
  129.             </plugin>
  130.         </plugins>
  131.     </build>
  132. </project>


建立BLOG_API模块**
在Dubbo官网服务化最佳实践中有提及，建议将服务接口、服务模型、服务异常等均放在 API 包中，我们也遵循其规范，右键项目New Module -> 名为BLOG_API和父项目类似，注意设置Maven Repository设置，版本号和父项目一致，可以从pom.xml中看到继承自父项目
API模块用于定义一些公有的实体类、工具类、异常类和服务接口，调用方引入该模块，通过接口调用服务而不用关心到底是哪一个Service是实现了该功能
建立完毕后注意执行mvn clean install 安装到本地仓库

  1. <?xml version="1.0" encoding="UTF-8"?>
  2. <project xmlns="http://maven.apache.org/POM/4.0.0"
  3.          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  4.          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  5.     <parent>
  6.         <artifactId>blog</artifactId>
  7.         <groupId>com.bwensun</groupId>
  8.         <version>0.0.1-SNAPSHOT</version>
  9.     </parent>
  10.     <modelVersion>4.0.0</modelVersion>
  12.     <artifactId>BLOG_API</artifactId>
  14. </project>


建立BLOG_USER_SERVICE模块和BLOG_Web模块
建立模块过程和之前方法一致
这里需要注意的是这两个项目我重新引入了SpringBoot相关的依赖，标记文件夹，并添加启动类，和配置文件使之成为一个单独的SpringBoot项目，用以启动和调用服务
Zookeeper的安装和启动连接：略
以下是pom.xml和application.yaml配置，启动类略
BLOG_USER_SERVICE模块**
pom.xml

  1. <?xml version="1.0" encoding="UTF-8"?>
  2. <project xmlns="http://maven.apache.org/POM/4.0.0"
  3.          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  4.          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  5.     <parent>
  6.         <artifactId>blog</artifactId>
  7.         <groupId>com.bwensun</groupId>
  8.         <version>0.0.1-SNAPSHOT</version>
  9.     </parent>
  10.     <modelVersion>4.0.0</modelVersion>
  12.     <artifactId>BLOG_USER_SERVICE</artifactId>
  14.     <dependencies>
  15.         <dependency>
  16.             <groupId>com.bwensun</groupId>
  17.             <artifactId>BLOG_API</artifactId>
  18.         </dependency>
  19.         <dependency>
  20.             <groupId>com.alibaba.boot</groupId>
  21.             <artifactId>dubbo-spring-boot-starter</artifactId>
  22.         </dependency>
  23.         <!--mybatis-->
  24.         <dependency>
  25.             <groupId>org.mybatis.spring.boot</groupId>
  26.             <artifactId>mybatis-spring-boot-starter</artifactId>
  27.         </dependency>
  28.         <dependency>
  29.             <groupId>org.mybatis.generator</groupId>
  30.             <artifactId>mybatis-generator-core</artifactId>
  31.         </dependency>
  32.         <!--druid连接池-->
  33.         <dependency>
  34.             <groupId>com.alibaba</groupId>
  35.             <artifactId>druid-spring-boot-starter</artifactId>
  36.         </dependency>
  37.         <!--mysql-->
  38.         <dependency>
  39.         <groupId>mysql</groupId>
  40.         <artifactId>mysql-connector-java</artifactId>
  41.         <scope>runtime</scope>
  42.     </dependency>
  43.     </dependencies>
  45.     <build>
  46.         <plugins>
  47.             <plugin>
  48.                 <groupId>org.mybatis.generator</groupId>
  49.                 <artifactId>mybatis-generator-maven-plugin</artifactId>
  50.                 <version>1.3.7</version>
  51.                 <configuration>
  52.                     <!--自定义路径,否则会自动识别GeneratorConfig.xml文件-->
  53.                     <!-- <configurationFiile>${basedir}/src/main/resources/generatorConfig.xml</configurationFile>-->
  54.                     <!--是为了运行mvn mybatis-generator:generate -e时显示具体过程-->
  55.                     <verbose>true</verbose>
  56.                     <!--为了生成文件时后一次生成的文件覆盖前一次生成的同名文件-->
  57.                     <overwrite>true</overwrite>
  58.                 </configuration>
  59.                 <dependencies>
  60.                     <dependency>
  61.                         <groupId>mysql</groupId>
  62.                         <artifactId>mysql-connector-java</artifactId>
  63.                         <version>5.1.44</version>
  64.                     </dependency>
  65.                 </dependencies>
  66.             </plugin>
  67.         </plugins>
  68.     </build>
  69. </project>

yaml

  1. dubbo:
  2.   application:
  3.     name: boot-order-service-consumer
  4.   registry:
  5.     #address: zookeeper://localhost:2181ip
  6.     address: zookeeper://ip:2181?backup=47.103.215.103:2182,47.103.215.103:2183
  7.     file: dubbo-registry/dubbo-registry.properties
  9. #  monitor:
  10. #    protocol: registry
  11. server:
  12.   port: 8081
  13. spring:
  14.   profiles:
  15.     include: druid
  16. mybatis:
  17.   mapper-locations: classpath:mapper/*.xml

启动类
注意@EnableDubbo这个注解要加上

  1. @SpringBootApplication
  2. @EnableDubbo
  3. public class BlogUserServiceApplication {
  4.     public static void main(String[] args) {
  5.         SpringApplication.run(BlogUserServiceApplication.class, args);
  6.     }
  7. }

BLOG_WEB模块
pom.xml

  1. <?xml version="1.0" encoding="UTF-8"?>
  2. <project xmlns="http://maven.apache.org/POM/4.0.0"
  3.          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  4.          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  5.     <parent>
  6.         <artifactId>blog</artifactId>
  7.         <groupId>com.bwensun</groupId>
  8.         <version>0.0.1-SNAPSHOT</version>
  9.     </parent>
  10.     <modelVersion>4.0.0</modelVersion>
  12.     <artifactId>BLOG_WEB</artifactId>
  14.     <dependencies>
  15.         <dependency>
  16.             <groupId>org.springframework.boot</groupId>
  17.             <artifactId>spring-boot-starter-web</artifactId>
  18.         </dependency>
  19.         <dependency>
  20.             <groupId>com.alibaba.boot</groupId>
  21.             <artifactId>dubbo-spring-boot-starter</artifactId>
  22.         </dependency>
  23.         <dependency>
  24.             <groupId>com.bwensun</groupId>
  25.             <artifactId>BLOG_API</artifactId>
  26.         </dependency>
  27.     </dependencies>
  28. </project>

yaml

  1. dubbo:
  2.   application:
  3.     name: boot-order-service-consumer
  4.   registry:
  5.     address: zookeeper://IP:2181?backup=47.103.215.103:2182,47.103.215.103:2183
  6.     file: dubbo-registry/dubbo-registry.properties
  8. #  monitor:
  9. #    protocol: registry
  10. server:
  11.   port: 8081

启动类

注意@EnableDubbo这个注解要加上

  1. @SpringBootApplication
  2. @EnableDubbo
  3. public class BlogWebApplication {
  4.     public static void main(String[] args) {
  5.         SpringApplication.run(BlogWebApplication.class, args);
  6.     }
  7. }

**

写个Demo

BLOG_API添加实体类、接口

  • 添加实体类
  1. @Getter
  2. @Setter
  3. @ToString
  4. public class User implements Serializable {
  5.     /**
  6.      * 主键
  7.      */
  8.     private Integer id;
  10.     /**
  11.      * 用户名
  12.      */
  13.     private String userName;
  15.     /**
  16.      * 密码
  17.      */
  18.     private String password;
  20.     private static final long serialVersionUID = 1L;
  21. }

  • 添加服务接口

    1. @Component
    2. public interface UserService {
    4.   /**
    5.    * 用户信息分页查询
    6.    * @return 分页用户对象
    7.    */
    8.   PageInfo<User> getUserList();
    9. }

BLOG_USER_SERVICE实现该接口

  • 实现该服务接口

注意：
Service为import ``com.alibaba.dubbo.config.annotation.``Service

  1. @Component
  2. @Service
  3. public class UserServiceImpl implements UserService {
  5.     @Resource
  6.     UserMapper userMapper;
  8.     @Override
  9.     public PageInfo<User> getUserList() {
  10.         PageHelper.startPage(1, 10);
  11.         List<User> users = userMapper.selectAll();
  12.         return new PageInfo<>(users);
  13.     }
  • 具体Dao层略

**

BLOG_WEB添加控制器

  1. @RestController
  2. @RequestMapping("user")
  3. public class UserController {
  5.     @Reference
  6.     UserService userService;
  8.     @RequestMapping("userList")
  9.     public PageInfo<User> getUserList(){
  10.         return userService.getUserList();
  11.     }
  12. }

测试

  1. 启动BLOG_USER_SERVICE项目来注册到ZK之中，控制台打印如下

image.png

  1. 启动BLOG_WEB项目，用于接受客户端的请求，同样他会连接ZK来获取服务image.png
  2. 访问localhost:8081/user/userList可以发现已经接受了返回的查询结果image.png

问题和解决

事实上，在实际测试中遇到了非常多问题，我把这些都记录下来，放到了

相关

  1. Dubbo官方文档
  2. Spring Boot-整合Dubbo