SpringBoot入门，Dubbo+Zookeeper简单入门案例_java中dubbo和zk使用的简单案例基于springboot

简介：

1、Dubbo：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。架构如下图所示（摘自官网）

 

 

 

2.Zookeeper：Apacahe Hadoop 的子项目，是一个树型的目录服务，支持变更推送，适合作为 Dubbo 服务的注册中心，工业强度较高，可用于生产环境，Dubbo官方推荐使用。执行流程如下图所示（摘自网站）

 

 

Dubbo与Zookeeper就简单介绍到这，详细请参考官方文档，下面开始进入实战练习。

1.安装Zookeeper

• 下载地址：https://mirrors.tuna.tsinghua.edu.cn/apache/zookeeper/，我下载是的3.5.5版本，选择3.5.5，之后下载

  apache-zookeeper-3.5.5-bin.tar.gz 
  

• 下载完后解压，目录结构如下：

• 修改配置文件，进入conf文件夹下，将zoo_sample.cfg重命名为zoo.cfg，zookeeper启动会默认加载这个配置文件，之后修改配置文件内容，设置数据及日志存储路径，并修改启动端口，避免与其他冲突，完整配置文件如下，主要配置的是dataDir数据存储路径、dataLogDir日志存储路径以及admin.serverPort服务启动端口（避免与其他端口冲突）。

# The number of milliseconds of each tick
tickTime=2000
# The number of ticks that the initial 
# synchronization phase can take
initLimit=10
# The number of ticks that can pass between 
# sending a request and getting an acknowledgement
syncLimit=5
# the directory where the snapshot is stored.
# do not use /tmp for storage, /tmp here is just 
# example sakes.
 
 
dataDir=D:\\Zookeeper-3.5.5\\data
dataLogDir=D:\\Zookeeper-3.5.5\\logs
 
 
# the port at which the clients will connect
 
 
clientPort=2181
admin.serverPort=8082
 
 
# the maximum number of client connections.
# increase this if you need to handle more clients
#maxClientCnxns=60
#
# Be sure to read the maintenance section of the 
# administrator guide before turning on autopurge.
#
# http://zookeeper.apache.org/doc/current/zookeeperAdmin.html#sc_maintenance
#
# The number of snapshots to retain in dataDir
#autopurge.snapRetainCount=3
# Purge task interval in hours
# Set to "0" to disable auto purge feature
#autopurge.purgeInterval=1

• 启动zookeeper，修改完配置文件后，进入到bin文件夹下，由于我是在window下，所以双击zkServer.cmd启动，启动成功如下图所示

启动后不要关闭窗口，最小化就行。

2.项目准备

新建一个SpringBoot项目dubbo-demo，包含三个子模块，分别为dubbo-demo-api、demo-demo-consumer及dubbo-demo-provider，目录结构如下：

  

其中dubbo-demo-consumer和dubbo-demo-provider都引入dubbo-demo-api，依赖关如下：

（1）dubbo-demo-api

• pom文件内容如下：就是新建一个springboot模块，没有引入其他依赖的默认状态

<?xml version="1.0" encoding="UTF-8"?>
<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.1.RELEASE</version>
        <relativePath/>
    </parent>
    <groupId>dubbo.demo.api</groupId>
    <artifactId>dubbo-demo-api</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>dubbo-demo-api</name>
    <description>Demo project for Spring Boot</description>
 
    <properties>
        <java.version>1.8</java.version>
        <project.bulid.sourceEncoding>UTF-8</project.bulid.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    </properties>
 
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter</artifactId>
        </dependency>
 
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>
 
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
 
</project>

• IDeviceService内容如下：简单定义了一个借口，包含一个sayHello()的方法

package dubbo.demo.api;
 
import java.io.Serializable;
 
public interface IDemoService {
    Serializable sayHello();
}

（2）dubbo-demo-consumer

• pom文件内容如下：引入dubbo-demo-api，dubbo，zookeeper依赖，顺便复习了下整合swagger，参考我的上一篇博客。

<?xml version="1.0" encoding="UTF-8"?>
<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.1.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>dubbo.demo.consumer</groupId>
    <artifactId>dubbo-demo-consumer</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>dubbo-demo-consumer</name>
    <description>Demo project for Spring Boot</description>
 
    <properties>
        <java.version>1.8</java.version>
        <project.bulid.sourceEncoding>UTF-8</project.bulid.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
 
        <!-- 引入dubbo-demo-api依赖 -->
        <dependency>
            <groupId>dubbo.demo.api</groupId>
            <artifactId>dubbo-demo-api</artifactId>
            <version>0.0.1-SNAPSHOT</version>
        </dependency>
 
        <!-- 引入swagger2依赖 -->
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
            <version>2.9.2</version>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger-ui</artifactId>
            <version>2.9.2</version>
        </dependency>
 
        <!-- 引入dubbo zookeeper依赖-->
        <dependency>
            <groupId>com.alibaba.boot</groupId>
            <artifactId>dubbo-spring-boot-starter</artifactId>
            <version>0.2.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.zookeeper</groupId>
            <artifactId>zookeeper</artifactId>
            <version>3.5.5</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>
 
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
 
</project>

• Swagger2Config内容如下：

package dubbo.demo.consumer.config;
 
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import springfox.documentation.builders.ApiInfoBuilder;
import springfox.documentation.builders.PathSelectors;
import springfox.documentation.builders.RequestHandlerSelectors;
import springfox.documentation.service.ApiInfo;
import springfox.documentation.service.Contact;
import springfox.documentation.spi.DocumentationType;
import springfox.documentation.spring.web.plugins.Docket;
import springfox.documentation.swagger2.annotations.EnableSwagger2;
 
@EnableSwagger2
@Configuration
public class Swagger2Config {
    @Bean
    public Docket swaggerPluginConfig(){
        return new Docket(DocumentationType.SWAGGER_2)
                .apiInfo(apiInfo())                     //Api文档描述
                .select()                               //选择哪些路径和Api会生成文档
                .apis(RequestHandlerSelectors.basePackage("dubbo.demo.consumer.controller"))    //对指定路径下Api进行监控
                .paths(PathSelectors.any())             //对所有路径进行监控
                .build();
    }
 
    private ApiInfo apiInfo(){
        return new ApiInfoBuilder()
                .title("Dubbo Demo接口文档")
                .description("API 接口文档")
                .termsOfServiceUrl("http://localhost")
                .version("1.0.0")
                .contact(new Contact("takano","","xxxxxx@qq.com"))
                .build();
    }
}

• DemoController内容如下：简单定义了一个请求方法sayHello()，通过@Reference来标记IDemoSerice接口的成员变量 demoService 是一个 dubbo 服务的引用，在sayHello()方法内的通过该接口向远端的服务提供者发起调用，客户端并没有实现IDemoService接口。其中参数version指定了服务的版本号，要与提供者提供的服务版本号一致。除此之外，@Reference还有许多其他的参数，请参考文档。

package dubbo.demo.consumer.controller;
 
import com.alibaba.dubbo.config.annotation.Reference;
import dubbo.demo.api.IDemoService;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
 
import java.io.Serializable;
 
@Api(value = "DemoController",tags = "dubbo-demo控制器")
@RestController
public class DemoController {
 
    @Reference(version = "1.0.0")
    private IDemoService demoService;
 
    @ApiOperation(value = "测试方法",tags = "dubbo-demo控制器")
    @GetMapping("/sayHello")
    public Serializable sayHello(){
        return demoService.sayHello();
    }
}

• 启动文件内容如下：使用@EnableDubbo注解启用dubbo，它是@EnableDubboConfig和@DubboComponentScan的组合形式，用来扫描服务消费者，即用@Reference注解标注，对其进行组装初始化操作，最终完成服务引用工作。

package dubbo.demo.consumer;
 
import com.alibaba.dubbo.config.spring.context.annotation.EnableDubbo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
 
@EnableDubbo
@SpringBootApplication
public class DubboDemoConsumerApplication {
 
    public static void main(String[] args) {
        SpringApplication.run(DubboDemoConsumerApplication.class, args);
    }
 
}

• 配置文件内容如下：

#服务启动端口
server.port=9001
 
#dubbo
#当前服务名
dubbo.application.name=dubbo-demo-consumer
#注册中心的协议和地址
dubbo.registry.protocol=zookeeper
dubbo.registry.address=localhost:2181
#连接监控中心
dubbo.monitor.protocol=registry
 

（3）dubbo-demo-provider

• pom文件内容如下：引入dubbo-demo-api，dubbo，zookeeper依赖。

<?xml version="1.0" encoding="UTF-8"?>
<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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.1.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>dubbo.demo.provider</groupId>
    <artifactId>dubbo-demo-provider</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>dubbo-demo-provider</name>
    <description>Demo project for Spring Boot</description>
 
    <properties>
        <java.version>1.8</java.version>
        <project.bulid.sourceEncoding>UTF-8</project.bulid.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    </properties>
 
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
 
        <!-- 引入dubbo-demo-api依赖 -->
        <dependency>
            <groupId>dubbo.demo.api</groupId>
            <artifactId>dubbo-demo-api</artifactId>
            <version>0.0.1-SNAPSHOT</version>
        </dependency>
 
        <!-- 引入dubbo zookeeper依赖 -->
        <dependency>
            <groupId>com.alibaba.boot</groupId>
            <artifactId>dubbo-spring-boot-starter</artifactId>
            <version>0.2.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.zookeeper</groupId>
            <artifactId>zookeeper</artifactId>
            <version>3.5.5</version>
        </dependency>
 
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>
 
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
 
</project>

• DemoService内容如下：实现了demo-service-api的IDemoService接口，并实现了具体方法，使用“dubbo的@Service”注解配置服务提供者，暴露该服务。version指定了服务的版本号，interfaceClass指定了服务提供者实现的接口类，其他相关参数请查看文档。@Component声明该类是一个组件。

package dubbo.demo.provider.service;
 
import com.alibaba.dubbo.config.annotation.Service;
import dubbo.demo.api.IDemoService;
import org.springframework.stereotype.Component;
 
import java.io.Serializable;
 
@Service(version = "1.0.0",interfaceClass = IDemoService.class)
@Component
public class DemoService implements IDemoService {
    @Override
    public Serializable sayHello() {
        return "Hello World";
    }
}

• 启动文件内容如下：同样使用@EnableDubbo注解启动dubbo。

package dubbo.demo.provider;
 
import com.alibaba.dubbo.config.spring.context.annotation.EnableDubbo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
 
@EnableDubbo
@SpringBootApplication
public class DubboDemoProviderApplication {
 
    public static void main(String[] args) {
        SpringApplication.run(DubboDemoProviderApplication.class, args);
    }
 
}

• 配置文件内容如下：

#服务启动端口
server.port=9002
 
#dubbo
#当前服务名
dubbo.application.name=dubbo-demo-provider
#注册中心的协议和地址
dubbo.registry.protocol=zookeeper
dubbo.registry.address=localhost:2181
#通信规则
dubbo.protocol.name=dubbo
dubbo.protocol.port=8365
#连接监控中心
dubbo.monitor.protocol=registry

3.测试

• 先启动服务提者dubbo-demo-provider，启动成功后，可以在zookeeper窗口下看到如下信息，说明在zookeeper中注册成功。

• 启动服务消费者dubbo-demo-consumer：同样，可以再zookeeper窗口下看到一条输出信息，说明在zookeeper中订阅成功。

• 由于我再服务消费者中整合了swagger，所以在浏览器中输入localhost:9001/swagger-ui.html，即可进入到api文档界面，测试暴露的api，也可以直接在浏览器输入localhost:9001/sayHello测试，结果如下图所示：

可以看到我们成功的远程调用了服务提供者，并返回结果。至此一个简单的dubbo+zookeeper入门案例就完成了。

如有错误请批评指正，我会及时修改，欢迎大佬指点，让我更快进步。