PancrasL的博客

dubbo 的原理和使用(完善中)

2021-04-14

1. 基础知识

1.1 什么是RPC

远程过程调用，简单的理解是一个节点请求另一个节点提供的服务

2. dubbo配置

2.1 安装ZooKeeper（Windows10环境）

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# windows
$ cd bin
$ zkServer.cmd
...
some info
...

# linux
$ cd bin
$ ./zkServer.sh start
... 
some info
...
  • zookeeper会占用8080端口，通过在 zoo.cfg 中添加 admin.serverPort=8888 解除8080端口的占用

2.2 安装监控中心（可选）

  • 克隆项目
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$ git clonegit clone https://github.com/apache/dubbo-admin.git
$ cd dubbo-admin
$ mvn clean package
  • 前端
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$ cd dubbo-admin-ui
npm install
npm run dev
  • 后端
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$ cd dubbo-admin-server
$ mvn clean package
$ cd target
$ java -jar dubbo-admin-server-0.3.0-SNAPSHOT.jar

2.3 Spring Demo

2.3.1 Provider

  • pom.xml
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<?xml version="1.0" encoding="UTF-8"?>
<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns="http://maven.apache.org/POM/4.0.0"
         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>indi.pancras</groupId>
    <artifactId>provider</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.apache.dubbo</groupId>
            <artifactId>dubbo</artifactId>
            <version>2.7.3</version>
        </dependency>
        <dependency>
            <groupId>org.apache.curator</groupId>
            <artifactId>curator-framework</artifactId>
            <version>2.12.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.curator</groupId>
            <artifactId>curator-recipes</artifactId>
            <version>2.12.0</version>
        </dependency>
    </dependencies>

</project>
  • provider.xml
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<?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.xsd
       http://dubbo.apache.org/schema/dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd">

    <!-- 1. 指定当前服务/应用的名字（不要和其他服务同名） -->
    <dubbo:application name="provider"/>

    <!-- 2. 指定注册中心的位置 -->
    <dubbo:registry address="zookeeper://localhost:2181"/>

    <!-- 3. 指定通信规则（通信协议、通信端口）  -->
    <dubbo:protocol name="dubbo" port="31111"/>

    <!-- 4. 暴露服务 -->
    <dubbo:service interface="provider.interfaces.ComputationalStorageService" ref="css"/>
    <bean id="css" class="provider.interfaces.impl.ComputationalStorageServiceImpl"/>
</beans>
  • MainApplication.java
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package provider;

import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.io.IOException;

import provider.interfaces.ComputationalStorageService;

/**
 * @author pancras
 * @create 2021/5/19 17:26
 */
public class MainApplication {
    public static void main(String[] args) throws IOException {
        ClassPathXmlApplicationContext ioc = new ClassPathXmlApplicationContext("provider.xml");
        ioc.start();
        ComputationalStorageService bean = ioc.getBean(ComputationalStorageService.class);
        System.out.println(bean);
        System.in.read();
    }
}
  • ComputationalStorageService.java
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package provider.interfaces;

/**
 * @author pancras
 * @create 2021/5/19 17:26
 */
public interface ComputationalStorageService {
    public String sayHello(String msg);

    public Integer wordCount(String filename);
}
  • ComputationalStorageServiceImpl.java
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package provider.interfaces.impl;

import provider.interfaces.ComputationalStorageService;

/**
 * 1. 将服务提供者注册到注册中心
 *    1.1 导入dubbo依赖
 *    1.2 配置服务提供者
 * 2. 让服务消费者去注册中心订阅服务提供者的服务地址
 *
 * @author pancras
 * @create 2021/5/19 17:26
 *
 */
public class ComputationalStorageServiceImpl implements ComputationalStorageService {
    public String sayHello(String msg) {
        return "Hello: " + msg;
    }

    @Override
    public Integer wordCount(String filename) {
        return null;
    }
}

2.3.2 Consumer

  • pom.xml
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<?xml version="1.0" encoding="UTF-8"?>
<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns="http://maven.apache.org/POM/4.0.0"
         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>indi.pancras</groupId>
    <artifactId>consumer</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>1.8</maven.compiler.source>
        <maven.compiler.target>1.8</maven.compiler.target>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.apache.dubbo</groupId>
            <artifactId>dubbo</artifactId>
            <version>2.7.3</version>
        </dependency>
        <dependency>
            <groupId>org.apache.curator</groupId>
            <artifactId>curator-framework</artifactId>
            <version>2.12.0</version>
        </dependency>
        <dependency>
            <groupId>org.apache.curator</groupId>
            <artifactId>curator-recipes</artifactId>
            <version>2.12.0</version>
        </dependency>
    </dependencies>

</project>
  • consumer.xml
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<?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.xsd
       http://dubbo.apache.org/schema/dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd">

    <!-- 1. 指定当前服务/应用的名字（不要和其他服务同名） -->
    <dubbo:application name="consumer"/>

    <!-- 2. 指定注册中心的位置 -->
    <dubbo:registry address="zookeeper://localhost:2181"/>

    <dubbo:reference interface="provider.interfaces.ComputationalStorageService"
                     id="demoService" timeout="5000" retries="3" version="*">
<!--         <dubbo:method name="sayHello" timeout="1000"></dubbo:method>-->
    </dubbo:reference>

</beans>
  • MainApplication.java
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package consumer;

import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.io.IOException;

import provider.interfaces.ComputationalStorageService;

/**
 * @author pancras
 * @create 2021/5/19 17:36
 */
public class MainApplication {
    public static void main(String[] args) throws IOException {
        ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("consumer.xml");

        ComputationalStorageService bean = applicationContext.getBean(ComputationalStorageService.class);
        String hello = bean.sayHello("Mike");
        System.out.println(hello);
    }
}

  • ComputationalStorageService.java
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package provider.interfaces;

/**
 * @author pancras
 * @create 2021/5/19 17:26
 */
public interface ComputationalStorageService {
    public String sayHello(String msg);

    public Integer wordCount(String filename);
}
Tags: all dubbo java rpc
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