Dubbo介绍
Dubbo是一款高性能、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。
核心部件功能
Remoting: 网络通信框架,实现了 sync-over-async 和
request-response 消息机制.
RPC: 一个远程过程调用的抽象,支持负载均衡、容灾和集群功能
Registry: 服务目录框架用于服务的注册和服务事件发布和订阅
工作原理
特性
- 面向接口代理的高性能RPC调用提供高性能的基于代理的远程调用能力,服务以接口为粒度,为开发者屏蔽远程调用底层细节。
- 智能负载均衡内置多种负载均衡策略,智能感知下游节点健康状况,显著减少调用延迟,提高系统吞吐量。
- 服务自动注册与发现支持多种注册中心服务,服务实例上下线实时感知。
- 高度可扩展能力遵循微内核+插件的设计原则,所有核心能力如Protocol、Transport、Serialization被设计为扩展点,平等对待内置实现和第三方实现。
- 运行期流量调度内置条件、脚本等路由策略,通过配置不同的路由规则,轻松实现灰度发布,同机房优先等功能。
- 可视化的服务治理与运维提供丰富服务治理、运维工具:随时查询服务元数据、服务健康状态及调用统计,实时下发路由策略、调整配置参数。
案例:
首先下载zookeeper(下载地址https://mirrors.tuna.tsinghua.edu.cn/apache/zookeeper/)解压到本地。启动Zookeeper注册中心,在解压后zookeeper-3.4.11文件夹bin下启动cmd,输入zkServer.cmd
若启动注册中心失败,则需要修改conf目录下zoo.cfg文件,如图。
启动dubbo控制台,通过java -jar jar包名命令启动。jar包下载地址:链接:https://pan.baidu.com/s/1m_4ktW19muxPKWpdKbufVQ 提取码:xy35
通过浏览器访问控制台,访问时要输入用户名:root与密码:root:
1.新建maven项目user-service-gmall,该项目包含了bean类、与接口(OrderService、UserService)
UserAddress类:
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;
}
}
OrderService接口:
public interface OrderService {
/**
* 初始化订单
* @param userId
*/
public List<UserAddress> initOrder(String userId);
}
UserService接口:
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);
}
2.创建user-service-provider01项目
pom文件中添加maven依赖:添加user-service-gmall项目依赖
<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.moon</groupId>
<artifactId>user-service-provider01</artifactId>
<version>0.0.1-SNAPSHOT</version>
<dependencies>
<dependency>
<groupId>com.moon</groupId>
<artifactId>user-service-gmall</artifactId>
<version>0.0.1-SNAPSHOT</version>
</dependency>
<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>
</dependencies>
</project>
UserServiceImpl类
public class UserServiceImpl implements UserService {
@Override
public List<UserAddress> getUserAddressList(String userId) {
// TODO Auto-generated method stub
System.out.println("UserServiceImpl..3.....");
UserAddress address1 = new UserAddress(1, "陕西省西安市", "1", "dd", "010-56253825", "Y");
UserAddress address2 = new UserAddress(2, "陕西省咸阳市", "1", "dd", "010-56253825", "N");
return Arrays.asList(address1,address2);
}
}
RunClass类
public class MainClass {
public static void main(String[] args) throws Exception{
System.out.println("开启服务");
ClassPathXmlApplicationContext ioc = new ClassPathXmlApplicationContext("provider.xml");
ioc.start();
System.in.read();
}
}
provider.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-provider01"></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="20882"></dubbo:protocol>
<bean id="userServiceImpl" class="com.moon.service.UserServiceImpl"></bean>
<!-- 4、暴露服务 ref:指向服务的真正的实现对象 -->
<dubbo:service interface="com.moon.user_service_gmall.service.UserService"
ref="userServiceImpl" timeout="1000" version="2.0.0">
<dubbo:method name="getUserAddressList" timeout="1000"></dubbo:method>
</dubbo:service>
</beans>
3.创建user-service-consumer项目
OrderServiceImpl类
@Service
public class OrderServiceImpl implements OrderService{
@Autowired
UserService userService;
public List<UserAddress> initOrder(String userId) {
// TODO Auto-generated method stub
List<UserAddress> addressList = userService.getUserAddressList(userId);
for (UserAddress userAddress : addressList) {
System.out.println(userAddress.getUserAddress()+"---"+userAddress.getId());
}
return addressList;
}
}
启动类MainClass
@SuppressWarnings("resource")
public class MainClass {
public static void main(String[] args) {
ClassPathXmlApplicationContext c = new ClassPathXmlApplicationContext("consumer.xml");
c.start();
OrderService orderService = (OrderService) c.getBean(OrderService.class);
orderService.initOrder("1");
System.out.println("调用完成....");
try {
System.in.read();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
consumer.xml配置文件
<?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.moon.service"></context:component-scan>
<dubbo:application name="order-service-consumer"></dubbo:application>
<dubbo:registry address="zookeeper://127.0.0.1:2181"></dubbo:registry>
<!-- 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.moon.user_service_gmall.service.UserService" <!--在user-service-provider中暴露的接口服务 -->
id="userService" timeout="5000" retries="3" version="*">
<!-- <dubbo:method name="getUserAddressList" timeout="1000"></dubbo:method> -->
</dubbo:reference>
</beans>
4.启动服务提供者与消费者,即启动user-service-provider01与user-service-consumer中MainClass中的main方法(先启动服务提供者)。
访问Dubbo后台监控系统,如图。