1.dubbo-demo-api

这里面主要是定义所有的接口，demo工程里就定义了一个测试接口，看一下该层的代码结构

DemoApi.java代码

package com.example.dubbo.demo.api;

import java.util.List;

import dubbo.demo.model.entity.Student;

/**
 * Demo 接口定义
 * @author 
 *
 */
public interface DemoApi {
    String sayHello(String name);
    void add(Student student);
    List<Student> getAll();
}

2.dubbo-demo-service

该层主要实现api的接口，因此该层依赖api层，pom文件的依赖如下

<dependency>
            <groupId>com.example.dubbo</groupId>
            <artifactId>dubbo-demo-api</artifactId>
            <version>0.0.1-SNAPSHOT</version>
        </dependency>

说明：需要在api层执行install的maven命令，把api的jar包生打包到本地.m2仓库。

该层代码结构如下:

aop包主要是记录每一个service方法调用时的入参，返回值，执行时间、接口的全名称等信息。
impl包实现api的接口逻辑
mapper包是mybatis与数据库交互的方法，与mapper.xml对应
mapping文件夹下保存所有mapper.xml文件
dubbo-config.xml 是dubbo暴露服务的配置文件

impl/DemoApiImpl.java代码

package com.example.dubbo.demo.service.impl;

import com.example.dubbo.demo.api.DemoApi;
import com.example.dubbo.demo.service.mapper.StudentMapper;

import dubbo.demo.model.entity.Student;

import java.util.List;

import org.apache.dubbo.config.annotation.Service;
import org.springframework.beans.factory.annotation.Autowired;

/**
 * 
 * @author chenlong12
 *
 */
@Service
public class DemoApiImpl implements DemoApi {
  
  @Autowired
  private StudentMapper studentMapper;
  /**
   * 实现 sayHello 接口
   *
   * @param name
   * @return
   */
  @Override
  public String sayHello(String name) {
    return "Hello, " + name + " (from Spring Boot with dubbo-2.7.1)";
  }

  @Override
  public void add(Student student) {
    // TODO Auto-generated method stub
    studentMapper.add(student);
  }

  @Override
  public List<Student> getAll() {
    // TODO Auto-generated method stub
    return studentMapper.getAll();
  }
}

mapper/StudentMapper.java代码

package com.example.dubbo.demo.service.mapper;

import java.util.List;

import dubbo.demo.model.entity.Student;

public interface StudentMapper {

  void add(Student student);
  List<Student> getAll();
}

mapping/StudentMapper.xml代码

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.example.dubbo.demo.service.mapper.StudentMapper">
  <resultMap id="StudentResultMap" type="dubbo.demo.model.entity.Student">
    <result column="id" jdbcType="INTEGER" property="id" />
    <result column="num" jdbcType="VARCHAR" property="num" />
    <result column="name" jdbcType="VARCHAR" property="name" />
    <result column="age" jdbcType="INTEGER" property="age" />
    <result column="sex" jdbcType="VARCHAR" property="sex" />
  </resultMap>
  <insert id="add" parameterType="dubbo.demo.model.entity.Student">
    insert into student (num, name, age,sex)
    values (#{num},#{name},#{age},#{sex})
  </insert>
  
  <!--我自己加的方法-->
  <select id="getAll" resultType="dubbo.demo.model.entity.Student">
    select * from student
  </select>
</mapper>

application.properties

dubbo-config.xml会引用该配置文件里的内容

spring.config.name=application

# spring 的环境配置
spring.profiles.active=dev
# 服务启动端口，即内置 tomcat 启动时占用的端口
server.port=8087

spring.aop.auto=true

spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://127.0.0.1:3306/school?useSSL=false&useUnicode=true&characterEncoding=UTF-8
spring.datasource.username=
spring.datasource.password=

mybatis.mapper-locations=classpath:mapping/*.xml
mybatis.type-aliases-package=dubbo.demo.model.entity
# dubbo config
# 应用定义了提供方应用信息，用于计算依赖关系；在 dubbo-admin 或 dubbo-monitor 会显示这个名字，方便辨识
my.dubbo.application.name=dubbo-demo-service
# 应用所属者
my.dubbo.application.owner=ll
# 应用所属组织
my.dubbo.application.organization=ll

# 使用 zookeeper 注册中心暴露服务，注意要先开启 zookeeper
# 注册中心id
my.dubbo.registry.id=zookeeper-registry
# 注册中心协议
my.dubbo.registry.protocol=zookeeper
# 注册中心地址
my.dubbo.registry.address=127.0.0.1:2181

# dubbo协议在20880端口暴露服务
# 协议名称
my.dubbo.protocol.name=dubbo
# 协议端口
my.dubbo.protocol.port=20880
# 协议访问log
my.dubbo.protocol.accesslog=dubbo-access.log
# 重试次数
my.dubbo.provider.retries=0
# 超时时间
my.dubbo.provider.timeout=3000
# 注册监控中心
my.dubbo.monitor.protocol=registry

dubbo-config.xml

这dubbo的配置文件，所有的服务都是通过这个配置文件发布出去

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
       xsi:schemaLocation="
        http://code.alibabatech.com/schema/dubbo
        http://code.alibabatech.com/schema/dubbo/dubbo.xsd
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">

    <!-- 定义了提供方应用信息，用于计算依赖关系；在 dubbo-admin 或 dubbo-monitor 会显示这个名字 -->
    <dubbo:application name="${my.dubbo.application.name}" owner="ll" organization="ll"  />

    <!-- 使用 zookeeper 注册中心暴露服务，注意要先开启 zookeeper-->
    <dubbo:registry id="zookeeper-registry" protocol="${my.dubbo.registry.protocol}" address="${my.dubbo.registry.address}"  />

    <!-- dubbo协议在20880端口暴露服务 -->
    <dubbo:protocol name="${my.dubbo.protocol.name}" port="${my.dubbo.protocol.port}" accesslog="dubbo-access.log"/>
    <dubbo:provider retries="0" timeout="30000"/>
    <dubbo:monitor protocol="registry"/>

  <bean id="demoApiImpl" class="com.example.dubbo.demo.service.impl.DemoApiImpl"></bean>
    <!-- 使用 dubbo 协议实现定义好的 Service Api 接口-->
    <dubbo:service interface="com.example.dubbo.demo.api.DemoApi" ref="demoApiImpl" retries="0" timeout="60000">
      <dubbo:method name="add" timeout="10000" retries="0" loadbalance="leastactive" actives="5" />
    </dubbo:service>
</beans>

详细的配置说明请参见dubbo官方文档

http://dubbo.apache.org/zh-cn/docs/user/references/xml/dubbo-service.html

DubboDemoServiceApplication.java

项目启动main方法，项目启动前需要先把zookeeper启动

package com.example.dubbo.demo.service;

import org.apache.dubbo.config.spring.context.annotation.DubboComponentScan;
import org.apache.dubbo.config.spring.context.annotation.EnableDubboConfig;
import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.ImportResource;

//@EnableDubboConfig
//@DubboComponentScan("com.example.dubbo.demo.service.impl")
@MapperScan("com.example.dubbo.demo.service.mapper")
@SpringBootApplication
@ImportResource(locations="classpath:dubbo-config.xml")
public class DubboDemoServiceApplication {

  public static void main(String[] args) {
    SpringApplication.run(DubboDemoServiceApplication.class, args);
  }

}