dubbo的学习使用（一）

Dubbo相关的说明性内容已经有很多了，这边就不再做说明了，具体还是参考官方的说明和示例
Dubbo中文官网
下面就仅说明个人的实践。
注册中心使用的是zookeeper，IDE使用的是Idea。

首先是原生Dubbo

1、api

在Idea中创建Maven工程，pom文件如下：

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

    <groupId>com.test</groupId>
    <artifactId>dubbo-api</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.10</version>
        </dependency>
    </dependencies>

</project>

使用lombok时Idea需要加载相应插件，否则会报错
类文件User.java：

package pojo;
import lombok.Data;
import java.io.Serializable;
@Data
public class User implements Serializable {
    private String id;
    private String name;
}

接口文件UserService.java：

package service;
import pojo.User;
public interface UserService {
    User selectByID(String id);
}

2、provider

在Idea中创建Maven工程，pom文件如下：

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

    <groupId>com.test</groupId>
    <artifactId>dubbo-provider</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <dependency>
            <groupId>org.apache.dubbo</groupId>
            <artifactId>dubbo</artifactId>
            <version>2.7.4.1</version>
        </dependency>
        <dependency>
            <groupId>org.apache.dubbo</groupId>
            <artifactId>dubbo-dependencies-zookeeper</artifactId>
            <version>2.7.4.1</version>
            <type>pom</type>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.10</version>
        </dependency>
        <dependency>
            <groupId>com.test</groupId>
            <artifactId>dubbo-api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
    </dependencies>
</project>

接口实现文件UserServiceImpl.java：

package Impl;
import pojo.User;
import service.UserService;
public class UserServiceImpl implements UserService {
    public User selectByID(String id) {
        User user = new User();
        user.setId(id);
        user.setName(id + ":name");
        return user;
    }
}

启动文件Provider.java：

import org.springframework.context.support.ClassPathXmlApplicationContext;
public class Provider {
    public static void main(String[] args) throws Exception {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(new String[]{"classpath:provider.xml"});
        context.start();
        System.in.read(); // 按任意键退出
    }
}

配置文件privider.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"
>

    <!-- 提供方应用信息，用于计算依赖关系 -->
    <dubbo:application name="hello-world-app"/>

    <!-- 使用zookeeper集群注册中心暴露服务地址 -->
    <!-- 连接zookeeper时，在连接串中添加timeout参数可以解决连接超时问题 -->
    <dubbo:registry protocol="zookeeper" address="192.168.42.128:2181,192.168.42.128:3181,192.168.42.128:4181&amp;timeout=15000"/>

    <!-- 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接口 -->
    <dubbo:service interface="service.UserService" ref="userService"/>

    <!-- 和本地bean一样实现服务 -->
    <bean id="userService" class="Impl.UserServiceImpl"/>
</beans>

3、consumer

在Idea中创建Maven工程，pom文件如下：

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

    <groupId>com.test</groupId>
    <artifactId>dubbo-consumer</artifactId>
    <version>1.0-SNAPSHOT</version>

    <dependencies>
        <dependency>
            <groupId>org.apache.dubbo</groupId>
            <artifactId>dubbo</artifactId>
            <version>2.7.4.1</version>
        </dependency>
        <dependency>
            <groupId>org.apache.dubbo</groupId>
            <artifactId>dubbo-dependencies-zookeeper</artifactId>
            <version>2.7.4.1</version>
            <type>pom</type>
        </dependency>
        <dependency>
            <groupId>com.test</groupId>
            <artifactId>dubbo-api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
    </dependencies>
</project>

启动文件consumer.java：

import org.springframework.context.support.ClassPathXmlApplicationContext;
import pojo.Action;
import pojo.User;
import service.ActionService;
import service.UserService;

public class Consumer {
    public static void main(String[] args) throws Exception {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(new String[]{"classpath:consumer.xml"});
        context.start();
        UserService demoService = (UserService)context.getBean("userService"); // 获取远程服务代理
        User user=demoService.selectByID("1"); // 执行远程方法
        System.out.println(user);
        System.in.read();
    }
}

配置文件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:context="http://www.springframework.org/schema/context"
       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://www.springframework.org/schema/context
       http://www.springframework.org/schema/context/spring-context-4.3.xsd
       http://dubbo.apache.org/schema/dubbo
       http://dubbo.apache.org/schema/dubbo/dubbo.xsd"
>

    <context:component-scan base-package="service">
        <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
    </context:component-scan>


    <!-- 消费方应用名，用于计算依赖关系，不是匹配条件，不要与提供方一样 -->
    <dubbo:application name="consumer-of-helloworld-app"/>

    <!-- 使用zookeeper集群注册中心暴露服务地址 -->
    <!-- 连接zookeeper时，在连接串中添加timeout参数可以解决连接超时问题 -->
    <dubbo:registry protocol="zookeeper" address="192.168.42.128:2181,192.168.42.128:3181,192.168.42.128:4181&amp;timeout=15000" />

    <!-- 生成远程服务代理，可以和本地bean一样使用demoService -->
    <dubbo:reference id="userService" interface="service.UserService"/>
</beans>

---

顺序启动provider、consumer即可

spring boot+Dubbo

1、spring boot provider

在Idea中创建spring boot工程，pom文件如下：

<?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>2.2.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.test</groupId>
    <artifactId>dubboprovider</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>dubboprovider</name>
    <description>Spring Boot+dubbo的provider示例</description>

    <properties>
        <java.version>1.8</java.version>
        <spring-boot.version>2.2.0.RELEASE</spring-boot.version>
        <dubbo.version>2.7.4.1</dubbo.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</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>

        <!-- Dubbo引用start -->
        <dependency>
            <groupId>org.apache.dubbo</groupId>
            <artifactId>dubbo-spring-boot-starter</artifactId>
            <version>2.7.4.1</version>
        </dependency>
        <!-- Dubbo引用end -->


        <!-- API引用start -->
        <dependency>
            <groupId>com.test</groupId>
            <artifactId>dubbo-api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <!-- API引用end -->

        <!-- Zookeeper dependencies start -->
        <dependency>
            <groupId>org.apache.dubbo</groupId>
            <artifactId>dubbo-dependencies-zookeeper</artifactId>
            <version>${dubbo.version}</version>
            <type>pom</type>
            <exclusions>
                <exclusion>
                    <groupId>org.slf4j</groupId>
                    <artifactId>slf4j-log4j12</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <!-- Zookeeper dependencies start -->
    </dependencies>

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

接口实现文件DefaultUserService.java：

package com.test.dubboprovider.Impl;

import org.apache.dubbo.config.annotation.Service;
import pojo.User;
import service.UserService;

@Service
public class DefaultUserService implements UserService {
    @Override
    public User selectByID(String id) {
        User user = new User();
        user.setId(id);
        user.setName(id + ":name");
        return user;
    }
}

applicatio.properties：

spring.application.name=hello-world-app
dubbo.scan.base-packages=com.test.dubboprovider.Impl
dubbo.registry.address=zookeeper://192.168.42.128:2181?backup=192.168.42.128:3181,192.168.42.128:4181&timeout=15000
dubbo.protocol.name=dubbo
#-1表示任意端口
dubbo.protocol.port=-1

主函数DubboProviderApplication.java：

package com.test.dubboprovider;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;

// 开启基于注解的dubbo功能（主要是包扫描@DubboComponentScan）
// 也可以在配置文件中使用dubbo.scan.base-package来替代   @EnableDubbo
@EnableAutoConfiguration
//@SpringBootApplication
public class DubboProviderApplication {
    public static void main(String[] args) {
        SpringApplication.run(DubboProviderApplication.class, args);
    }
}

2、spring boot consumer

在Idea中创建spring boot工程，pom文件如下：

<?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>2.2.2.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.test</groupId>
    <artifactId>dubboconsumer</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>dubboconsumer</name>
    <description>Spring Boot+dubbo的consumer示例</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</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>

        <!-- Dubbo引用start -->
        <dependency>
            <groupId>org.apache.dubbo</groupId>
            <artifactId>dubbo-spring-boot-starter</artifactId>
            <version>2.7.4.1</version>
        </dependency>
        <!-- Dubbo引用end -->

        <!-- API引用start -->
        <dependency>
            <groupId>com.test</groupId>
            <artifactId>dubbo-api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <!-- API引用end -->

        <!-- Zookeeper dependencies start -->
        <dependency>
            <groupId>org.apache.dubbo</groupId>
            <artifactId>dubbo-dependencies-zookeeper</artifactId>
            <version>2.7.4.1</version>
            <type>pom</type>
            <exclusions>
                <exclusion>
                    <groupId>org.slf4j</groupId>
                    <artifactId>slf4j-log4j12</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <!-- Zookeeper dependencies start -->
    </dependencies>

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

</project>

applicatio.properties：

dubbo.registry.address=zookeeper://192.168.42.128:2181?backup=192.168.42.128:3181,192.168.42.128:4181&timeout=15000
spring.application.name=consumer-of-helloworld-app
server.port=8090

主函数DubboProviderApplication.java：

package com.test.dubboconsumer;
import org.apache.dubbo.config.annotation.Reference;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.ApplicationRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.EnableAutoConfiguration;
import org.springframework.context.annotation.Bean;
import service.UserService;

@EnableAutoConfiguration
public class DubboconsumerApplication {
    @Reference
    private UserService userService;
    private final Logger logger = LoggerFactory.getLogger(getClass());
    public static void main(String[] args) {
        SpringApplication.run(DubboconsumerApplication.class, args);
    }

    @Bean
    public ApplicationRunner runner() {
        return args -> System.out.println(userService.selectByID("mercyblitz"));
    }

}

---

相继启动spring boot provider、spring boot consumer即可

以上就是dubbo的简单示例