dubbo 入门

1、入门案例

1.1、服务提供者

• 服务提供者（包括服务实现类和接口）需要将自己的“服务接口类”暴露出来
• 需要配置引入 jar 包的依赖
• 可以将服务提供者和消费者之间公共的 bean 和 service 接口暴露出来
• 在 IDEA 中配置时，只需要在“父项目”中配置 pom.xml 即可

依赖

<dependencies>
		
		<dependency>
			<groupId>com.alibabagroupId>
			<artifactId>dubboartifactId>
			<version>2.6.2version>
		dependency>

		<dependency>
			<groupId>org.springframeworkgroupId>
			<artifactId>spring-webmvcartifactId>
			<version>4.3.16.RELEASEversion>
		dependency>

		<dependency>
			<groupId>org.apache.curatorgroupId>
			<artifactId>curator-frameworkartifactId>
			<version>2.8.0version>
		dependency>
		<dependency>
			<groupId>org.apache.curatorgroupId>
			<artifactId>curator-recipesartifactId>
			<version>2.8.0version>
		dependency>

		<dependency>
			<groupId>com.101tecgroupId>
			<artifactId>zkclientartifactId>
			<version>0.10version>
		dependency>
		
		<dependency>
			<groupId>org.apache.curatorgroupId>
			<artifactId>curator-frameworkartifactId>
			<version>2.12.0version>
		dependency>

		<dependency>
			<groupId>com.bigguy.servicegroupId>
			<artifactId>service-interfaceartifactId>
			<version>0.0.1-SNAPSHOTversion>
		dependency>
	dependencies>

接口

public interface UserService {
    public String sayHello();
}

接口实现类

public class UserServiceImpl implements UserService {
    @Override
    public String sayHello() {
        return "hello , bigguy!";
    }
}

配置文件

    
    <dubbo:application name="service-app"  />

    
    <dubbo:registry address="zookeeper://127.0.0.1:2181" />

    
    <dubbo:protocol name="dubbo" port="20880" />

    
    <dubbo:service interface="com.bigguy.service.UserService" ref="demoService" />

    
    <bean id="demoService" class="com.bigguy.service.UserServiceImpl" />
beans>

测试方法

public class MainApp {
    public static void main(String args[]) throws IOException {
        String xmlPath = "classpath:context.xml";
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(xmlPath);
        context.start();
        System.in.read(); // 按任意键退出
    }
}

1.2、服务消费者

• 只需要编写接口类（UserService，这个接口类和服务提供者一致），实现从 zookeeper 中获取

配置文件

    
    <dubbo:application name="consumer-of-helloworld-app"  />

    
    <dubbo:registry address="zookeeper://127.0.0.1:2181" />

    
    <dubbo:reference id="demoService" interface="com.bigguy.service.UserService" />

beans>

测试方法

public class ConsumerMainApp {

    public static void main(String args[]) throws IOException {

        String xmlPath = "classpath:context.xml";
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(xmlPath);

        UserService service = context.getBean(UserService.class);
//        UserService service = (UserService)context.getBean("demoService");
        String str = service.sayHello();

        System.out.println(str);

        System.in.read();

    }
}

2、整合SpringBoot(使用 zookeeper注册中心)

2.1、服务端

a. pom

在 github 中搜索可以得到

https://github.com/apache/incubator-dubbo-spring-boot-project

<dependency>
    <groupId>com.alibaba.bootgroupId>
    <artifactId>dubbo-spring-boot-starterartifactId>
    <version>0.1.1version>
dependency>

b. 配置文件（application.properties )

dubbo.application.name=service-provider
dubbo.registry.address=127.0.0.1:2181
dubbo.registry.protocol=zookeeper

dubbo.protocol.name=dubbo
dubbo.protocol.port=20880

c. 暴露接口

@Service   	// 使用的是 dubbo 的 service 注解
@Component
public class UserServiceImpl implements UserService {

    public User getUserById(Integer id) {
        return new User(1,"jeck");
    }
}

d. 开启基于注解的 dubbo

@EnableDubbo   	// 开启基于注解的dubbo
@SpringBootApplication
public class ServiceConsumerApplication {

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

2.2、服务消费者

a. 配置文件

server.port=8081

dubbo.application.name=service-consumer

dubbo.registry.address=127.0.0.1:2181
dubbo.registry.protocol=zookeeper

b. 引用 service

@Reference 引用 service

@Controller
public class UserController {

    @Reference    // 使用 dubbo 的reference
    UserService service;  

    @ResponseBody
    @GetMapping("user")
    public User getUser(){
        User user = service.getUserById(1);
        return user;
    }

c. 开启基于主机的配置

@EnableDubbo    // 开启基于注解的 dubbo
@SpringBootApplication
public class ServiceConsumerApplication {

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

3、SpringBoot 使用Dubbo(不通过zookeeper)

**参考地址：**https://github.com/alibaba/dubbo-spring-boot-starter

3.1、服务提供者

a、pom.xml

• 不用继承父springboot 方式

<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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0modelVersion>

    <groupId>com.bigguy.framegroupId>
    <artifactId>frame-client-providerartifactId>
    <version>1.0-SNAPSHOTversion>

    <properties>
        <project.build.sourceEncoding>UTF-8project.build.sourceEncoding>
        <maven.compiler.source>1.8maven.compiler.source>
        <maven.compiler.target>1.8maven.compiler.target>
    properties>


    <dependencyManagement>
        <dependencies>
            <dependency>
                
                <groupId>org.springframework.bootgroupId>
                <artifactId>spring-boot-dependenciesartifactId>
                <version>1.4.3.RELEASEversion>
                <type>pomtype>
                <scope>importscope>
            dependency>
        dependencies>
    dependencyManagement>

    <dependencies>
        
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>
 
        <dependency>
            <groupId>com.alibaba.spring.bootgroupId>
            <artifactId>dubbo-spring-boot-starterartifactId>
            <version>2.0.0version>
        dependency>

        <dependency>
            <groupId>com.101tecgroupId>
            <artifactId>zkclientartifactId>
            <version>0.10version>
            <exclusions>
                <exclusion>
                    <groupId>org.slf4jgroupId>
                    <artifactId>slf4j-log4j12artifactId>
                exclusion>
                <exclusion>
                    <groupId>log4jgroupId>
                    <artifactId>log4jartifactId>
                exclusion>
            exclusions>
        dependency>
    dependencies>

project>

b、服务提供者配置

spring.application.name=dubbo-spring-boot-starter
spring.dubbo.server=true

# 表示不使用 zookeeper 等服务中心
spring.dubbo.registry=N/A

c、服务提供者的服务实例

使用 Dubbo 的注解 Service

@Service(interfaceClass = IHelloService.class)
@Component
public class HelloServiceImpl implements IHelloService {
  //...
}

d、启动类

• 启动Dubbo

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

3.2、服务消费者

a、pom.xml

• 和服务提供者的pom一致

b、消费者使用服务提供者的服务

@Reference(url = “dubbo://127.0.0.1:20880”) ，在 Reference 中指定连接的 url

@Component
public class HelloConsumer {
  @Reference(url = "dubbo://127.0.0.1:20880")
  private IHelloService iHelloService;

}

c、消费者启动类

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

4、使用注册中心

参考地址：https://www.cnblogs.com/Alandre/p/6490142.html

4-1、服务提供者配置

server.port=8081
server.context-path=/
spring.application.name=dubbo-spring-boot-starter
spring.dubbo.protocol.name=dubbo
spring.dubbo.protocol.port=20880
spring.dubbo.server=true
spring.dubbo.registry=zookeeper://172.30.0.177:2181

4-2、服务消费者

server.port=8080
spring.application.name=dubbo-spring-boot-starter-consumer
spring.dubbo.registry.address=zookeeper://172.30.0.177:2181
spring.dubbo.scan=org.spring.springboot.dubbo