1、zookeeper 下载、运行
zookeeper是dobbo推荐使用的注册中心，zookeeper为我们的分布式项目提供：配置维护、域名服务、节点存储、获取数据等等。
下载地址：https://www-eu.apache.org/dist/zookeeper/
选择相应版本，我这里用的是3.5.6版本：apache-zookeeper-3.5.6-bin.tar.gz
解压后，在conf目录下，复制zoo_sample.cfg粘贴重命名为zoo.cfg
配置如下内容：
tickTime=2000
initLimit=10
syncLimit=5
dataDir=/Users/zm/Downloads/zookeeper/data
dataLogDir=/Users/zm/Downloads/zookeeper/logs
clientPort=2181
运行zookeeper
在bin目录下，有运行的脚本，我用的是Mac，在cmd输入，即可运行zookeeper
./bin/zkServer.sh start
启动完成后，zookeeper://127.0.0.1:2181就是注册中心的地址。
2、创建springboot工程
首先创建一个springboot工程作为父模块。
2.1 创建一个api子模块
api子模块用于定义接口，不需要启动类，可以删除Application启动类， 我们这里定义一个获取服务器信息的接口，为负载均衡服务器信息。
package com.duboo.api;
import java.util.Map;
public interface DubboService {
Map<String, Object> getServiceInfo();
}
2.2 创建一个provider子模块
首先application.properties中添加
server.port=8090
dubbo.application.id=dubbo-provider
dubbo.application.name=dubbo-provider
dubbo.monitor.protocol=dubbo-registry
dubbo.registry.address=zookeeper://127.0.0.1:2181
dubbo.protocol.name=dubbo
dubbo.protocol.port=20880
然后pom.xml中添加
<dependencies>
<!-- 引用api子模块 -->
<dependency>
<groupId>com.dubbo</groupId>
<artifactId>api</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
<!-- apache的springboot dubbo依赖 -->
<dependency>
<groupId>org.apache.dubbo</groupId>
<artifactId>dubbo-spring-boot-starter</artifactId>
<version>2.7.3</version>
</dependency>
<!-- zookeeper -->
<dependency>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
<version>3.5.6</version>
<exclusions>
<exclusion>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
</exclusion>
<exclusion>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
</exclusion>
<exclusion>
<groupId>io.netty</groupId>
<artifactId>netty</artifactId>
</exclusion>
</exclusions>
</dependency>
<!-- Zookeeper客户端，封装了大量ZooKeeper常用API操作 -->
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-recipes</artifactId>
<version>4.2.0</version>
</dependency>
</dependencies>
然后，实现api子模块DubboService接口
import com.duboo.api.DubboService;
import org.apache.dubbo.config.annotation.Service;
import org.apache.dubbo.rpc.RpcContext;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.util.HashMap;
import java.util.Map;
@Service
public class DubboServiceImpl implements DubboService {
private Logger logger = LoggerFactory.getLogger(DubboServiceImpl.class);
@Override
public Map<String, Object> getServiceInfo() {
String fullURL = RpcContext.getContext().getUrl().toFullString();
Map<String, Object> map = new HashMap<>();
map.put("FullURL", fullURL);
logger.info("-----fullURL = {}", fullURL);
return map;
}
}
这里注意是@Service引用org.apache.dubbo.config.annotation.Service。
最后，在springboot启动中添加@EnableDubbo，启动服务即可。
@EnableDubbo
@SpringBootApplication
public class ProviderApplication {
public static void main(String[] args) {
SpringApplication.run(ProviderApplication.class, args);
}
}
2.3 创建一个consumer子模块
首先application.properties中添加
server.port=8091
dubbo.application.id=dubbo-consumer
dubbo.application.name=dubbo-consumer
dubbo.monitor.protocol=dubbo-registry
dubbo.registry.address=zookeeper://127.0.0.1:2181
dubbo.protocol.name=dubbo
dubbo.protocol.port=20880
然后pom.xml中添加
<dependencies>
<!-- 引用api子模块 -->
<dependency>
<groupId>com.dubbo</groupId>
<artifactId>api</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
<!-- apache的springboot dubbo依赖 -->
<dependency>
<groupId>org.apache.dubbo</groupId>
<artifactId>dubbo-spring-boot-starter</artifactId>
<version>2.7.3</version>
</dependency>
<!-- zookeeper -->
<dependency>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
<version>3.5.6</version>
<exclusions>
<exclusion>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-log4j12</artifactId>
</exclusion>
<exclusion>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
</exclusion>
<exclusion>
<groupId>io.netty</groupId>
<artifactId>netty</artifactId>
</exclusion>
</exclusions>
</dependency>
<!-- Zookeeper客户端，封装了大量ZooKeeper常用API操作 -->
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-recipes</artifactId>
<version>4.2.0</version>
</dependency>
<!-- web依赖 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
<version>2.1.6.RELEASE</version>
</dependency>
</dependencies>
然后，创建ConsumerController类
import com.duboo.api.DubboService;
import org.apache.dubbo.config.annotation.Reference;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
@RequestMapping("/api/")
public class ConsumerController {
// random 随机，默认的
// roundrobin 轮询
// leastactive //最少活跃
// consistenthash //一致性Hash
@Reference(loadbalance = "roundrobin")
private DubboService dubboService;
@GetMapping("getInfo")
public Object getServiceInfo() {
return dubboService.getServiceInfo();
}
}
这里注意是调用DubboService服务用到的负载均衡策略是轮询访问，默认是随机
最后，在springboot启动中添加@EnableDubbo，启动consumer服务即可。
@EnableDubbo
@SpringBootApplication
public class ConsumerApplication {
public static void main(String[] args) {
SpringApplication.run(ConsumerApplication.class, args);
}
}
2.4 创建多个provider子模块
这一步是用于测试负载均衡策略，不需要测试的话可以略，复制一个provider子模块重命名provider2
修改application.properties中的端口，启动服务即可
server.port=8091
dubbo.application.id=dubbo-provider
dubbo.application.name=dubbo-provider
dubbo.monitor.protocol=dubbo-registry
dubbo.registry.address=zookeeper://127.0.0.1:2181
dubbo.protocol.name=dubbo
dubbo.protocol.port=20881
测试访问：http://localhost:8091/api/getInfo 可以看见
dubbo://192.168.43.55:20880/com.duboo.api.DubboService
dubbo://192.168.43.55:20881/com.duboo.api.DubboService
两个服务轮询打印。
最后源码github地址
https://github.com/zss945/dubbo-master
