Spring Cloud Alibaba微服务开发(三) - Dubbo(中)[Dubbo整合SpringBoot]

0. 背景

说起Dubbo为什么要和SpringBoot进行整合，一句话：大势所趋。

SpringBoot毕竟是当前统治Java开发的生态圈核心框架。
它的自动装配，健康检查，简易快速开发等功能能够让Dubbo发挥其更大的价值。

1. 创建项目骨架

我们创建一个pom项目，命名为: dubbo-springboot-demo。
在它下面我们创建两个模块，分别为springboot-provider, pom类型; springboot-consumer, jar类型。
springboot-provider下面创建2个模块，分别为sample-api和sample-provider，都是jar类型。
创建完毕后，项目结构见下图:

hierarchy

在主项目中加入lombok依赖

<dependencies>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <optional>true</optional>
    </dependency>
</dependencies>

2. 服务提供者

我们先来构建服务提供者的接口声明

在sample-api项目下添加一个接口
HelloService

package org.genesis.javacollector.dubbo.provider.api;

public interface HelloService {
    String sayHello(String name);
}

在sample-provider项目中添加dubbo和springboot所需要的必要的依赖

<dependencies>
    <dependency>
        <groupId>org.genesis</groupId>
        <artifactId>sample-api</artifactId>
        <version>1.0-SNAPSHOT</version>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <dependency>
        <groupId>org.apache.dubbo</groupId>
        <artifactId>dubbo-spring-boot-starter</artifactId>
        <version>2.7.5</version>
    </dependency>
    <dependency>
        <groupId>org.apache.zookeeper</groupId>
        <artifactId>zookeeper</artifactId>
        <version>3.4.9</version>
    </dependency>
    <dependency>
        <groupId>org.apache.curator</groupId>
        <artifactId>curator-framework</artifactId>
        <version>4.0.1</version>
    </dependency>
    <dependency>
        <groupId>org.apache.curator</groupId>
        <artifactId>curator-recipes</artifactId>
        <version>4.0.1</version>
    </dependency>
    <dependency>
        <groupId>com.101tec</groupId>
        <artifactId>zkclient</artifactId>
        <version>0.10</version>
    </dependency>
</dependencies>

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

添加接口的实现
HelloServiceImpl

package org.genesis.javacollector.dubbo.provider.impl.service;

import org.apache.dubbo.config.annotation.Service;
import org.genesis.javacollector.dubbo.provider.api.HelloService;
import org.springframework.beans.factory.annotation.Value;

@Service(version = "1.0-SNAPSHOT", interfaceClass = HelloService.class)
public class HelloServiceImpl implements HelloService {
    @Value("${dubbo.application.name}")
    private String serviceName;

    @Override
    public String sayHello(String name) {
        return String.format("[%s]: Hello, %s", serviceName, name);
    }
}

配置dubbo
application.properties

spring.application.name=springboot-provider

dubbo.application.name=sample-provider
dubbo.registry.protocol=zookeeper
dubbo.registry.address=zookeeper://127.0.0.1:2181
dubbo.protocol.name=dubbo
dubbo.protocol.port=20880

程序主入口添加Dubbo组件扫描 @DubboComponentScan
(注: 这个步骤很容易忘记)
ProviderApplication

package org.genesis.javacollector.dubbo.provider.impl;

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

@DubboComponentScan
@SpringBootApplication
public class ProviderApplication {
    public static void main(String[] args) {
        SpringApplication.run(ProviderApplication.class, args);
    }
}

3. 服务消费者

在sample-consumer项目中添加dubbo和springboot所需要的必要的依赖
同sample-provider

添加一个controller
ConsumerController

package org.genesis.javacollector.dubbo.consumer.controller;

import lombok.extern.slf4j.Slf4j;
import org.apache.dubbo.config.annotation.Reference;
import org.genesis.javacollector.dubbo.provider.api.HelloService;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/consumer")
@Slf4j
public class ConsumerController {
    @Reference(version = "1.0-SNAPSHOT")
    private HelloService helloService;

    @GetMapping(value = "/test")
    public void test() {
        String hello = helloService.sayHello("KG");
        log.info(hello);
    }
}

添加Dubbo配置
application.properties

#dubbo configuration
dubbo.application.name=dubbo-consumer
dubbo.registry.protocol=zookeeper
dubbo.registry.address=zookeeper://127.0.0.1:2181

#避免端口冲突
server.port=8085

ConsumerApplication入口程序无变化，不需要添加任何额外的dubbo注解。

运行程序:

启动Zookeeper
启动sample-provider
启动springboot-consumer
浏览器输入: http://localhost:8085/consumer/test
客户端输出结果:
[sample-provider]: Hello, KG