Dubbo介绍及使用

1. Dubbo介绍

1.1 RPC

Remote Procedure Call

远程过程调用

9.2 Dubbo架构

9.3 Dubbo在Zookeeper中注册信息的结构

2 Dubbo使用

2.1 创建Common工程

• group id：com.atguigu.dubbo
• artifact id：Pro20-dubbo-common
• package：jar

public class Employee implements Serializable {
    private static final long serialVersionUID = 1L;
    private Integer empId;
    private String empName;
    private Double salary;
    ……
}

public interface EmployeeRemoteService {
    List<Employee> getEmployeeByConditionRemote(Employee employee);
}

2.2 创建Provider工程

• group id：com.atguigu.dubbo
• artifact id：Pro21-dubbo-provider
• package：war

<dependency>
    <groupId>cglib</groupId>
    <artifactId>cglib</artifactId>
    <version>2.2</version>
</dependency>
<dependency>
    <groupId>org.aspectj</groupId>
    <artifactId>aspectjweaver</artifactId>
    <version>1.6.8</version>
</dependency>
<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>dubbo</artifactId>
    <version>2.5.5</version>
</dependency>
<dependency>
    <groupId>com.github.sgroschupf</groupId>
    <artifactId>zkclient</artifactId>
    <version>0.1</version>
</dependency>
<dependency>
    <groupId>com.atguigu.dubbo</groupId>
    <artifactId>Pro20-dubbo-common</artifactId>
    <version>0.0.1-SNAPSHOT</version>
</dependency>

配置web.xml

<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath:spring-dubbo.xml</param-value>
</context-param>
<listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

Spring配置文件中Dubbo的配置

<?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://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
    <!-- 1.配置Dubbo应用名称 -->
    <dubbo:application name="atguigu-dubbo-provider"/>
    <!-- 2.指定注册中心位置 -->
    <dubbo:registry protocol="zookeeper" address="192.168.56.150" port="2181"/>
    <!-- 3.指定consumer访问provider时使用的端口号 -->
    <dubbo:protocol name="dubbo" port="20880"/>
    <!-- 4.配置接口的实现类 -->
    <bean id="employeeServiceImpl" class="com.atguigu.dubbo.service.impl.EmployeeServiceImpl"></bean>
    <!-- 5.将实现类关联到接口 -->
    <dubbo:service interface="com.atguigu.dubbo.api.EmployeeRemoteService" ref="employeeServiceImpl"></dubbo:service>
</beans>

EmployeeServiceImpl

public class EmployeeServiceImpl implements EmployeeRemoteService {
    @Override
    public List<Employee> getEmployeeByConditionRemote(Employee employee) {
        System.out.println(employee);
        List<Employee> empList = new ArrayList<>();
        empList.add(new Employee(111, "empName111", 111.11));
        empList.add(new Employee(222, "empName222", 222.22));
        empList.add(new Employee(333, "empName333", 333.33));
        return empList;
    }
}

2.3 创建Consumer工程

• group id：com.atguigu.dubbo
• artifact id：Pro22-dubbo-consumer
• package：war

配置web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xmlns="http://java.sun.com/xml/ns/javaee"
         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
         version="2.5">
    <servlet>
        <servlet-name>springDispatcherServlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>classpath:spring-mvc.xml</param-value>
        </init-param>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>springDispatcherServlet</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
</web-app>

配置Spring-mvc.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"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-4.3.xsd
                           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://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
    <!-- SpringMVC相关配置 -->
    <context:component-scan
                            base-package="com.atguigu.dubbo.handler" />
    <bean id="viewResolver"
          class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/" />
        <property name="suffix" value=".jsp" />
    </bean>
    <mvc:annotation-driven />
    <mvc:default-servlet-handler />
    <!-- Dubbo配置：指定应用名称 -->
    <dubbo:application name="atguigu-dubbo-consumer"/>
    <!-- Dubbo配置：指定Dubbo注册中心 -->
    <dubbo:registry protocol="zookeeper" address="192.168.56.150" port="2181"></dubbo:registry>
    <!-- Dubbo配置：引用接口代表的服务 -->
    <dubbo:reference id="employeeRemoteService" interface="com.atguigu.dubbo.api.EmployeeRemoteService"/>
</beans>

EmployeeHandler

@Controller
public class EmployeeHandler {
    @Autowired
    private EmployeeRemoteService employeeRemoteService;
    @RequestMapping("/get/emp/list")
    public String getEmpList() {
        Employee employee = new Employee(666, "empName666", 666.66);
        List<Employee> list = employeeRemoteService.getEmployeeByConditionRemote(employee);
        for (Employee employee2 : list) {
            System.out.println(employee2);
        }
        return "target";
    }
}