Dubbo实践-526互联

Dubbo是阿里巴巴公司开源的一个高性能优秀的服务框架，使得应用可通过高性能的 RPC 实现服务的输出和输入功能，可以和Spring框架无缝集成。
Dubbo是一款高性能、轻量级的开源Java RPC框架，它提供了三大核心能力：面向接口的远程方法调用，智能容错和负载均衡，以及服务自动注册和发现。
--(摘自《百度百科》)

演示远程调用和服务自动注册和和发现。首先demo结构如图所示：

dubbo-api module提供接口服务，dubbo-consumer module是消费者，dubbo-provider module是服务提供者，dubbo-consumer和dubbo-provider同时依赖于dubbo-appi.

dubbo-api module仅仅提供接口，没有其他逻辑。

dubbo-api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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.7.12</version>
    <relativePath/> <!-- lookup parent from repository -->
  </parent>

  <groupId>com.mike.study</groupId>
  <artifactId>dubbo-api</artifactId>
  <version>0.0.1</version>
  <name>dubbo-api</name>
  <description>Demo project for Spring Boot</description>
  <properties>
    <java.version>8</java.version>
  </properties>

  <dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter</artifactId>
    </dependency>

    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-test</artifactId>
      <scope>test</scope>
    </dependency>
  </dependencies>

  <build>
    <plugins>
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
      </plugin>
    </plugins>
  </build>

</project>

接口类UserService，设定一个login的方法。

import com.mike.study.domain.UserInfo;

public interface UserService {
  UserInfo login(UserInfo userInfo);
}

同时，方便统一管理对象，设定demain.UserInfo类, 由于实体类是要在网上传输，所以实体类是需要继承Serializable接口，否则会报错。

import java.io.Serializable;

public class UserInfo implements Serializable {
  private String account;
  private String password;

  public String getAccount() {
    return account;
  }

  public void setAccount(String account) {
    this.account = account;
  }

  public String getPassword() {
    return password;
  }

  public void setPassword(String password) {
    this.password = password;
  }
}

至此，api module已经准备完毕。接下来创建provider，提供服务并且注册到zookeeper上。所以要事先准备好zookeeper，参考网上资料，这里不展开介绍安装教程。

dubbo-provider的pom.xml需要引入zookeeper和dubbo相关依赖。

<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
  <modelVersion>4.0.0</modelVersion>
  <parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.7.12</version>
    <relativePath/> <!-- lookup parent from repository -->
  </parent>
  <groupId>com.mike.study</groupId>
  <artifactId>dubbo-provider</artifactId>
  <version>0.0.1</version>
  <name>dubbo-provider</name>
  <description>Demo project for Spring Boot</description>
  <properties>
    <java.version>8</java.version>
  </properties>
  <dependencies>
    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-web</artifactId>
    </dependency>

    <dependency>
      <groupId>com.mike.study</groupId>
      <artifactId>dubbo-api</artifactId>
      <version>0.0.1</version>
    </dependency>

    <dependency>
      <groupId>com.alibaba.spring.boot</groupId>
      <artifactId>dubbo-spring-boot-starter</artifactId>
      <version>2.0.0</version>
    </dependency>

    <dependency>
      <groupId>com.101tec</groupId>
      <artifactId>zkclient</artifactId>
      <version>0.10</version>
    </dependency>

    <dependency>
      <groupId>org.apache.zookeeper</groupId>
      <artifactId>zookeeper</artifactId>
      <version>3.4.10</version>
      <exclusions>
        <exclusion>
          <groupId>org.slf4j</groupId>
          <artifactId>slf4j-log4j12</artifactId>
        </exclusion>
        <exclusion>
          <groupId>log4j</groupId>
          <artifactId>log4j</artifactId>
        </exclusion>
      </exclusions>
    </dependency>

    <dependency>
      <groupId>org.springframework.boot</groupId>
      <artifactId>spring-boot-starter-test</artifactId>
      <scope>test</scope>
    </dependency>
  </dependencies>

  <build>
    <plugins>
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
      </plugin>
    </plugins>
  </build>

</project>

配置application.yml文件，设置好zookeeper的地址，dubbo框架会把服务自动注册到zookeeper上，避免同时启动会和consumer的端口有冲突，需要设定provider的端口为8081。

 1 spring:
 2   dubbo:
 3     application:
 4       name: dubbo-provider
 5     protocol:
 6       name: dubbo
 7       port: 20880
 8     registry:
 9       address: zookeeper://127.0.0.1:2181
10 server:
11   port: 8081

接下来，实现服务的逻辑，这里简单修改下user信息后直接返回出去。

 1 import com.alibaba.dubbo.config.annotation.Service;
 2 import com.mike.study.api.UserService;
 3 import com.mike.study.domain.UserInfo;
 4 import org.springframework.stereotype.Component;
 5 
 6 @Component
 7 @Service
 8 public class UserServiceImpl implements UserService {
 9   @Override
10   public UserInfo login(UserInfo userInfo) {
11     UserInfo reUser = new UserInfo();
12     reUser.setAccount("账号:"+ userInfo.getAccount());
13     reUser.setPassword("密码:"+ userInfo.getPassword());
14 
15     return reUser;
16   }
17 }

这里用到了2个注解，@Component将当前类交给springboot容器管理，@Service是dubbo的注解，将接口注册到zookeeper上供订阅者使用。

注意，上面注解外，还需要在启动类添加注解来启动dubbo自动配置。

 1 import com.alibaba.dubbo.spring.boot.annotation.EnableDubboConfiguration;
 2 import org.springframework.boot.SpringApplication;
 3 import org.springframework.boot.autoconfigure.SpringBootApplication;
 4 import org.springframework.context.ConfigurableApplicationContext;
 5 
 6 @SpringBootApplication
 7 @EnableDubboConfiguration // 启用dubbo自动配置
 8 public class DubboProviderApplication {
 9 
10   public static void main(String[] args) {
11     ConfigurableApplicationContext
12             context = SpringApplication.run(DubboProviderApplication.class, args);
13   }
14 
15 }

自此，provider也准备好，最后看consumer如何消费服务。

dubbo-consumer由于是要冲zookeeper上拿到接口，所以也要引入zookeeper等相关依赖。

 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>2.7.12</version>
 9     <relativePath/> <!-- lookup parent from repository -->
10   </parent>
11   <groupId>com.mike.study</groupId>
12   <artifactId>dubbo-consumer</artifactId>
13   <version>0.0.1-SNAPSHOT</version>
14   <name>dubbo-consumer</name>
15   <description>Demo project for Spring Boot</description>
16   <properties>
17     <java.version>8</java.version>
18   </properties>
19   <dependencies>
20     <dependency>
21       <groupId>org.springframework.boot</groupId>
22       <artifactId>spring-boot-starter-web</artifactId>
23     </dependency>
24 
25     <dependency>
26       <groupId>com.mike.study</groupId>
27       <artifactId>dubbo-api</artifactId>
28       <version>0.0.1</version>
29     </dependency>
30 
31     <dependency>
32       <groupId>com.alibaba.spring.boot</groupId>
33       <artifactId>dubbo-spring-boot-starter</artifactId>
34       <version>2.0.0</version>
35     </dependency>
36 
37     <dependency>
38       <groupId>com.101tec</groupId>
39       <artifactId>zkclient</artifactId>
40       <version>0.10</version>
41     </dependency>
42 
43     <dependency>
44       <groupId>org.apache.zookeeper</groupId>
45       <artifactId>zookeeper</artifactId>
46       <version>3.4.10</version>
47       <exclusions>
48         <exclusion>
49           <groupId>org.slf4j</groupId>
50           <artifactId>slf4j-log4j12</artifactId>
51         </exclusion>
52         <exclusion>
53           <groupId>log4j</groupId>
54           <artifactId>log4j</artifactId>
55         </exclusion>
56       </exclusions>
57     </dependency>
58 
59     <dependency>
60       <groupId>org.springframework.boot</groupId>
61       <artifactId>spring-boot-starter-test</artifactId>
62       <scope>test</scope>
63     </dependency>
64   </dependencies>
65 
66   <build>
67     <plugins>
68       <plugin>
69         <groupId>org.springframework.boot</groupId>
70         <artifactId>spring-boot-maven-plugin</artifactId>
71       </plugin>
72     </plugins>
73   </build>
74 
75 </project>

同样配置application.yml，指定zookeeper和服务端口。

 1 spring:
 2   dubbo:
 3     application:
 4       name: dubbo-consumer
 5     protocol:
 6       name: dubbo
 7       port: 20880
 8     registry:
 9       address: zookeeper://127.0.0.1:2181
10 server:
11   port: 8082

添加一个controller层用来调用UserService服务，添加 @Reference注解拿到provider的远程接口。

 1 import com.alibaba.dubbo.config.annotation.Reference;
 2 import com.mike.study.api.UserService;
 3 import com.mike.study.domain.UserInfo;
 4 import org.springframework.web.bind.annotation.GetMapping;
 5 import org.springframework.web.bind.annotation.RestController;
 6 
 7 
 8 @RestController
 9 public class UserController {
10   @Reference
11   UserService userService;
12 
13   @GetMapping("/login")
14   public UserInfo login(UserInfo userInfo){
15     UserInfo result = userService.login(userInfo);
16     return  result;
17   }
18 }

同样，consumer也要启动dubbo的自动配置。

 1 import com.alibaba.dubbo.spring.boot.annotation.EnableDubboConfiguration;
 2 import org.springframework.boot.SpringApplication;
 3 import org.springframework.boot.autoconfigure.SpringBootApplication;
 4 
 5 @SpringBootApplication
 6 @EnableDubboConfiguration
 7 public class DubboConsumerApplication {
 8 
 9   public static void main(String[] args) {
10     SpringApplication.run(DubboConsumerApplication.class, args);
11   }
12 
13 }

依次跑起zookeeper，provider服务，consumer服务。查看zookeeper的节点，可以看到，consumer和provider节点。

在浏览器上访问consumer：http://localhost:8082/login?account=test&password=123，效果如下