Dubbo 简易教程

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。
本博客只说明简单的远程方法调用。

准备工作

官网下载 zookeeper ：
3.5 版本下载 apache-zookeeper-3.5.5-bin.tar.gz 压缩包，之前的版本下载不带 bin 的压缩包。
解压之后首先进入 conf 目录把 zoo_sample.cfg 改成 zoo.cfg，并把数据存储目录改成自己的目录，然后进入 bin 目录 cmd 运行 zkServer.cmd 启动 zookeeper

dataDir=../data

quickstart

公共接口工程
在这里插入图片描述

实体类 Student.java

public class Student implements Serializable {
    
    
	
	private static final long serialVersionUID = 1L;
	
	private String sid;
	private String sname;
	private int age;
	
	public Student(String sid, String sname, int age) {
    
    
		super();
		this.sid = sid;
		this.sname = sname;
		this.age = age;
	}
	......
}

提供端接口

public interface ProviderService {
    
    
	
	List<Student> getStuList(String sname);
}

消费端接口

public interface ConsumerService {
    
    

	List<Student> useStuInfo(String sname);
}

服务提供工程

pom.xml

<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>4.0.0</modelVersion>
  <groupId>com.xiao</groupId>
  <artifactId>dubboDemo-provider</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  
  <properties>
  	<java.version>1.8</java.version>
  </properties>
  
  <dependencies>
  	<dependency>
  		<groupId>com.xiao</groupId>
  		<artifactId>dubboDemo-interface</artifactId>
  		<version>0.0.1-SNAPSHOT</version>
  	</dependency>
  	
  	<!-- https://mvnrepository.com/artifact/com.alibaba/dubbo -->
	<dependency>
	    <groupId>com.alibaba</groupId>
	    <artifactId>dubbo</artifactId>
	    <version>2.6.5</version>
	</dependency>
  	
  	<!-- https://mvnrepository.com/artifact/org.apache.curator/curator-framework -->
	<dependency>
	    <groupId>org.apache.curator</groupId>
	    <artifactId>curator-framework</artifactId>
	    <version>4.1.0</version>
	</dependency>
  	
  </dependencies>
</project>

服务提供接口实现类

public class ProviderServiceImpl implements ProviderService {
    
    

	public List<Student> getStuList(String sname) {
    
    
		Student stu1 = new Student("01", "张三", 20);
		Student stu2 = new Student("05", "张三", 18);
		return Arrays.asList(stu1, stu2);
	}

}

提供端 dubbo 配置 provider.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:dubbo="http://dubbo.apache.org/schema/dubbo"
       xmlns="http://www.springframework.org/schema/beans"
       xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
       http://dubbo.apache.org/schema/dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd">

    <!-- 当前应用（服务）的名称 -->
    <dubbo:application name="provider-getStuList"/>
    
    <!-- 注册中心地址 -->
    <dubbo:registry address="zookeeper://127.0.0.1:2181"/>
    
    <!-- 用dubbo协议在20880端口暴露服务 -->
    <dubbo:protocol name="dubbo" port="20880"/>
    
    <!-- 声明需要暴露的服务  -->
    <dubbo:service interface="com.xiao.service.ProviderService" ref="provService"/> <!-- 接口 -->
    
    <bean id="provService" class="com.xiao.service.impl.ProviderServiceImpl"/>  <!-- 实现 -->
    
</beans>

测试类

public class MainTest {
    
    

	@SuppressWarnings("resource")
	public static void main(String[] args) throws IOException {
    
    
		ClassPathXmlApplicationContext ac = new ClassPathXmlApplicationContext("provider.xml");
		ac.start();
		
		System.in.read(); 
	}
}

ac.start(); System.in.read(); 确保该服务不被关闭
运行该测试类即可把该服务注册到 zookeeper 注册中心，以供其他接口调用

服务消费工程

pom 依赖同上
服务消费接口实现

@Service
public class ConsumerServiceImpl implements ConsumerService {
    
    
	@Autowired
	ProviderService providerService;
	
	public List<Student> useStuInfo(String sname) {
    
    
		
		List<Student> stuList = providerService.getStuList(sname);
		System.err.println("------------------获取到 provider查询的学生信息----------------------");
		System.err.println(stuList);
		return stuList;
	}
	
}

消费端 dubbo 配置 consumer.xml

<?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://dubbo.apache.org/schema/dubbo"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd
                    http://dubbo.apache.org/schema/dubbo  http://dubbo.apache.org/schema/dubbo/dubbo.xsd">
 
    <!-- 消费方应用名，不要与提供方一样 -->
    <dubbo:application name="consumer-service"  />
 
    <!-- 注册中心暴露发现服务地址 -->
    <dubbo:registry address="zookeeper://127.0.0.1:2181" />
 
    <!-- 生成远程服务代理，应用暴露的 provider 端接口 -->
    <dubbo:reference id="proService" interface="com.xiao.service.ProviderService" />
    
</beans>

测试类

public class MainTest {
    
    

	public static void main(String[] args) {
    
    
		ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("consumer.xml");
        context.start();
        ProviderService proService = (ProviderService)context.getBean("proService"); // 获取远程服务代理
        List<Student> stuList = proService.getStuList("张三"); // 执行远程方法
        System.out.println("------------------获取到 provider查询的学生信息----------------------");
		System.out.println(stuList); // 显示调用结果
	}
}

这里的消费端接口和实现其实在本测试中都没有用到，当使用 IoC 注入方式测试时可以用到该接口与实现

先启动服务提供工程的测试类，把服务暴露到注册中心；再启动服务消费端的测试类，即可调用服务提供方的接口
在这里插入图片描述

dubbo与springboot整合

服务提供工程

pom.xml

<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>4.0.0</modelVersion>
  <groupId>com.xiao</groupId>
  <artifactId>dubboBoot-provider</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  
  <parent>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-parent</artifactId>
	<version>2.1.4.RELEASE</version>
	<relativePath/> <!-- lookup parent from repository -->
  </parent>
  
	<properties>
		<java.version>1.8</java.version>
	</properties>

	<dependencies>
		<dependency>
	  		<groupId>org.springframework.boot</groupId>
	  		<artifactId>spring-boot-starter</artifactId>
	  	</dependency>
	  	
		<dependency>
	  		<groupId>com.xiao</groupId>
	  		<artifactId>dubboDemo-interface</artifactId>
	  		<version>0.0.1-SNAPSHOT</version>
	  	</dependency>
  	
		<!-- Dubbo Spring Boot Starter -->
	    <dependency>
			<groupId>com.alibaba.boot</groupId>
			<artifactId>dubbo-spring-boot-starter</artifactId>
			<version>0.2.0</version>
		</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>

application.properties

server.port=8081

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

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

服务提供类接口实现

import java.util.Arrays;
import java.util.List;

import org.springframework.stereotype.Component;

import com.alibaba.dubbo.config.annotation.Service;
import com.xiao.entity.Student;
import com.xiao.service.ProviderService;

@Service(timeout = 30000)
@Component
public class ProviderServiceImpl implements ProviderService {
    
    

	public List<Student> getStuList(String sname) {
    
    
		Student stu1 = new Student("01", "张三", 20);
		Student stu2 = new Student("05", "张三", 18);
		return Arrays.asList(stu1, stu2);
	}

}

注意：该类的 @Service 注解是 dubbo 包里的

启动类加入 @EnableDubbo 注解，启动程序，即可把服务暴露到注册中心

服务消费工程

pom.xml

	<dependencies>
		<dependency>
	  		<groupId>org.springframework.boot</groupId>
	  		<artifactId>spring-boot-starter-web</artifactId>
	  	</dependency>
	
		<dependency>
	  		<groupId>com.xiao</groupId>
	  		<artifactId>dubboDemo-interface</artifactId>
	  		<version>0.0.1-SNAPSHOT</version>
	  	</dependency>
	  	
		<!-- Dubbo Spring Boot Starter -->
	    <dependency>
			<groupId>com.alibaba.boot</groupId>
			<artifactId>dubbo-spring-boot-starter</artifactId>
			<version>0.2.0</version>
		</dependency>
	
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-test</artifactId>
			<scope>test</scope>
		</dependency>
	</dependencies>

application.properties

server.port=8082

dubbo.application.name=dobbo-boot-consumer
dubbo.registry.address=zookeeper://127.0.0.1:2181

服务消费类接口实现

@Service
public class ConsumerServiceImpl implements ConsumerService {
    
    

	@Reference(timeout = 30000)
	ProviderService providerService;
	
	public List<Student> useStuInfo(String sname) {
    
    
		
		List<Student> stuList = providerService.getStuList(sname);
		System.out.println("------------------调用provider方法完成----------------------");
		return stuList;
	}

}

该类的 @Service 注解是 spring 的，@Reference 是 dubbo 包里的，表示引用的是外部接口

controller

@RestController
public class ConsumerController {
    
    

	@Autowired
	ConsumerService consumerService;
	
	@RequestMapping("/getStus")
	public List<Student> getStus(@RequestParam("sname") String sname) {
    
    
		System.out.println("---------获取信息的学生姓名：" + sname);
		List<Student> stuInfo = consumerService.useStuInfo(sname);
		return stuInfo;
	}
}

同样，在启动类加上 @EnableDubbo 注解，启动，在网页上发送请求，即可获取服务提供类暴露的方法

准备工作

quickstart

服务提供工程

服务消费工程

dubbo与springboot整合

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