Dubbo专栏:Dubbo分布式系统入门

Posted 2021-04-05 园码生活

了解Dubbo就得先了解分布式的基本理论，那什么是分布式系统？

        分布式系统就是若干个独立计算机的集合，这些计算机就像独立的单个相关的系统。分布式系统就是建立网络之上的系统。

Dubbo的发展演变

什么是RPC？

Dubbo核心概念

       Dubbo是一款高性能，轻量级的开源RPC框架，它提供了三大核心能力，面向接口的远程方法调用，智能容错和均衡负载，以及服务自动注册和发现。

想了解详细的技术文档可以上中英文网

http://dubbo.apache.org/zh-cn/  中文网

http://dubbo.apache.org/en-us/   英文网

搭建管理控制台

工程目录如下

公共的接口

package com.dubbo.common.bean;
import java.io.Serializable;
/**
 * 用户地址
 * @author lfy
 *
 */
public class UserAddress implements Serializable {
   
   private Integer id;
    private String userAddress; //用户地址
    private String userId; //用户id
    private String consignee; //收货人
    private String phoneNum; //电话号码
    private String isDefault; //是否为默认地址    Y-是     N-否
    
    public UserAddress() {
      super();
      // TODO Auto-generated constructor stub
   }
    
   public UserAddress(Integer id, String userAddress, String userId, String consignee, String phoneNum,
                       String isDefault) {
      super();
      this.id = id;
      this.userAddress = userAddress;
      this.userId = userId;
      this.consignee = consignee;
      this.phoneNum = phoneNum;
      this.isDefault = isDefault;
   }
   
   public Integer getId() {
      return id;
   }
   public void setId(Integer id) {
      this.id = id;
   }
   public String getUserAddress() {
      return userAddress;
   }
   public void setUserAddress(String userAddress) {
      this.userAddress = userAddress;
   }
   public String getUserId() {
      return userId;
   }
   public void setUserId(String userId) {
      this.userId = userId;
   }
   public String getConsignee() {
      return consignee;
   }
   public void setConsignee(String consignee) {
      this.consignee = consignee;
   }
   public String getPhoneNum() {
      return phoneNum;
   }
   public void setPhoneNum(String phoneNum) {
      this.phoneNum = phoneNum;
   }
   public String getIsDefault() {
      return isDefault;
   }
   public void setIsDefault(String isDefault) {
      this.isDefault = isDefault;
   }
    
    


}

package com.dubbo.common.service;
public interface OrderService {
    public void initOrder(String userId);
}

package com.dubbo.common.service;
import com.dubbo.common.bean.UserAddress;
import java.util.List;
/**
 * 用户服务
 * @author lfy
 *
 */
public interface UserService {
   
   /**
    * 按照用户id返回所有的收货地址
    * @param userId
    * @return
    */
   public List<UserAddress> getUserAddressList(String userId);
}

提供服务者

package com.dubbo.service.impl;
import com.dubbo.common.bean.UserAddress;
import com.dubbo.common.service.UserService;
import java.util.Arrays;
import java.util.List;
public class UserServiceImpl implements UserService {


   public List<UserAddress> getUserAddressList(String userId) {
      System.out.println("UserServiceImpl.....old...");
      // TODO Auto-generated method stub
      UserAddress address1 = new UserAddress(1, "北京市昌平区宏福科技园综合楼3层", "1", "李老师", "010-56253825", "Y");
      UserAddress address2 = new UserAddress(2, "深圳市宝安区西部硅谷大厦B座3层（深圳分校）", "1", "王老师", "010-56253825", "N");
      /*try {
         Thread.sleep(4000);
      } catch (InterruptedException e) {
         // TODO Auto-generated catch block         e.printStackTrace();
      }*/
      return Arrays.asList(address1,address2);
   }
}

创建一个提供消费者

package com.dubbo.service.impl;
import com.dubbo.common.bean.UserAddress;
import com.dubbo.common.service.OrderService;
import com.dubbo.common.service.UserService;
import java.util.List;
public class OrderServiceImpl implements OrderService {

    UserService userService;
    @Override
    public void initOrder(String userId) {
        List<UserAddress>addressList=userService.getUserAddressList(userId);
        System.out.println(addressList);
    }
}

提供者工程项目引入架包

<!-- 引入dubbo -->
<!-- https://mvnrepository.com/artifact/com.alibaba/dubbo -->
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>dubbo</artifactId>
    <version>2.6.2</version>
</dependency>
<!-- 注册中心使用的是zookeeper，引入操作zookeeper的客户端端 -->
<dependency>
    <groupId>org.apache.curator</groupId>
    <artifactId>curator-framework</artifactId>
    <version>2.12.0</version>
</dependency>

提供者的配置文件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://code.alibabatech.com/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
      http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
   <!-- 1、指定当前服务/应用的名字（同样的服务名字相同，不要和别的服务同名） -->
   <dubbo:application name="user-service-provider"></dubbo:application>
   
   <!-- 2、指定注册中心的位置 -->
   <!-- <dubbo:registry address="zookeeper://127.0.0.1:2181"></dubbo:registry> -->
   <dubbo:registry protocol="zookeeper" address="127.0.0.1:2181"></dubbo:registry>
   
   <!-- 3、指定通信规则（通信协议？通信端口） -->
   <dubbo:protocol name="dubbo" port="20880"></dubbo:protocol>
   
   <!-- 4、暴露服务   ref：指向服务的真正的实现对象 -->
   <dubbo:service interface="com.dubbo.common.service.UserService"
      ref="userService" timeout="1000" version="1.0.0">
      <dubbo:method name="getUserAddressList" timeout="1000"></dubbo:method>
   </dubbo:service>
   <bean id="userService" class="com.dubbo.service.impl.UserServiceImpl"></bean>
   <!--统一设置服务提供方的规则  -->
   <dubbo:provider timeout="1000"></dubbo:provider>
<!--   -->
<!--   -->
   <!-- 连接监控中心 -->
   <dubbo:monitor protocol="registry"></dubbo:monitor>
   
</beans>

测试服务提供者

package com.dubbo.service.impl;
import java.io.IOException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class MainApplication {
   
   public static void main(String[] args) throws IOException {
      ClassPathXmlApplicationContext ioc = new ClassPathXmlApplicationContext("provider.xml");
      ioc.start();
      
      System.in.read();
   }

消费者配置文件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:dubbo="http://dubbo.apache.org/schema/dubbo"
   xmlns:context="http://www.springframework.org/schema/context"
   xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.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
      http://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
   <context:component-scan base-package="com.dubbo.service.impl"></context:component-scan>
   <dubbo:application name="order-service-consumer"></dubbo:application>
   
   <dubbo:registry address="zookeeper://127.0.0.1:2181"></dubbo:registry>
   
   <!--  配置本地存根-->
   
   <!--声明需要调用的远程服务的接口；生成远程服务代理  -->
   <!-- 
      1）、精确优先 (方法级优先，接口级次之，全局配置再次之)
      2）、消费者设置优先(如果级别一样，则消费方优先，提供方次之)
   -->
   <!-- timeout="0" 默认是1000ms-->
   <!-- retries="":重试次数，不包含第一次调用，0代表不重试-->
   <!-- 幂等（设置重试次数）【查询、删除、修改】、非幂等（不能设置重试次数）【新增】 -->
   <dubbo:reference interface="com.dubbo.common.service.UserService"
      id="userService" timeout="5000" retries="3" version="*">
      <!-- <dubbo:method name="getUserAddressList" timeout="1000"></dubbo:method> -->
   </dubbo:reference>
      
   <!-- 配置当前消费者的统一规则：所有的服务都不检查 -->
   <dubbo:consumer check="false" timeout="5000"></dubbo:consumer>
   <dubbo:monitor protocol="registry"></dubbo:monitor>
   <!-- <dubbo:monitor address="127.0.0.1:7070"></dubbo:monitor> -->
   
</beans>

修改serviceimpl类目

package com.dubbo.service.impl;
import com.dubbo.common.bean.UserAddress;
import com.dubbo.common.service.OrderService;
import com.dubbo.common.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import java.util.List;
@Service
public class OrderServiceImpl implements OrderService {

    @Autowired
    UserService userService;
    @Override
    public void initOrder(String userId) {
        List<UserAddress>addressList=userService.getUserAddressList(userId);
        System.out.println(addressList);
    }
}

消费者的测试类

package com.dubbo.service.impl;
import java.io.IOException;
import com.dubbo.common.service.OrderService;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class MainApplication {
   
   @SuppressWarnings("resource")
   public static void main(String[] args) throws IOException {
      ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("consumer.xml");
      
      OrderService orderService = applicationContext.getBean(OrderService.class);
      
      orderService.initOrder("1");
      System.out.println("调用完成....");
      System.in.read();
   }

}

   祝大家能有所收获！！本人是一路自学过来