社区电商系统架构之服务治理篇：dubbo的实验

本篇实验dubbo的去中心化服务治理能力

dubbo介绍

服务治理开源项目，具备服务自动伸缩能力。当有部分dubbo服务实例不可用时，其通过注册中心（本实验是zookeeper注册中心），将不可用的服务在客户端调用层删除。

 

实验主机

 

localhostdubbo 服务实例

localhost casdemo web示例，允当dubbo服务消费者

localhost zookeeper实例

zookeeper启动

./zkServer.sh start

 

可以配置多个zookeeper实例

服务端

发布demoService.sayHello()服务

</pre></div><div>DubboProviderMain</div><div><pre name="code" class="java">package casdemo;

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class DubboProviderMain {
	 /** 
     * @Title main 
     * @Description TODO 
     * @Author weizhi2018 
     * @param args 
     * @throws 
     */  
  
    public static void main(String[] args) throws Exception {  
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(  
                new String[]{"remote-provider.xml"});  
        context.start();  
  
        System.out.println("Press any key to exit.");  
        System.in.read();  
    }  
}

运行JAVA main函数

 

remote-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://code.alibabatech.com/schema/dubbo        http://code.alibabatech.com/schema/dubbo/dubbo.xsd">
 
    <!-- 提供方应用信息，用于计算依赖关系 -->
    <dubbo:application name="casdemo"  />
 
    <!-- 使用multicast广播注册中心暴露服务地址 
    <dubbo:registry address="multicast://224.5.6.7:1234" />-->
 
    <!-- 用dubbo协议在20880端口暴露服务 -->
    <dubbo:protocol name="dubbo" port="20880" />
 
 	<dubbo:registry protocol="zookeeper" address="192.168.161.73:21818"/>
 
    <!-- 声明需要暴露的服务接口 -->
    <dubbo:service interface="casdemo.DemoService" ref="demoService" />
 
    <!-- 和本地bean一样实现服务 -->
    <bean id="demoService" class="casdemo.DemoServiceImpl" />
 
</beans>

 

客户端

客户端为web工程

 

webconsumer.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://code.alibabatech.com/schema/dubbo
		http://code.alibabatech.com/schema/dubbo/dubbo.xsd">

	<!--注册中心地址配置-->
	<bean id="propertyConfigurer"
		class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
		<property name="locations">
			<list>
				<value>classpath:dubbo.properties</value>
			</list>
		</property>
	</bean>

	<!-- 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 -->
	<!-- 应用配置，用于配置当前应用信息，不管该应用是提供者还是消费者。 -->
	<dubbo:application name="consumer-of-casdemo"/>

	<!-- 使用zookeeper注册中心暴露发现服务地址 -->
	<dubbo:registry protocol="zookeeper" address="192.168.161.73:21818" />
	
	
	 <!-- 使用multicast广播注册中心暴露发现服务地址
    <dubbo:registry address="multicast://224.5.6.7:1234" /> -->
 
    <!-- 生成远程服务代理，可以和本地bean一样使用demoService -->
    <dubbo:reference id="demoService" interface="casdemo.DemoService" /> 

</beans>

Login

调用dubbo服务

demoService.sayHello()

</pre></div><div><pre name="code" class="java">package casdemo;

import java.io.IOException;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
import org.springframework.web.context.support.WebApplicationContextUtils;

/**
 * Servlet implementation class Login
 */
public class Login extends HttpServlet {
	private static final long serialVersionUID = 1L;
     
	//@Autowired
	DemoService demoService;
    /**
     * @see HttpServlet#HttpServlet()
     */
    public Login() {
    	
        super();
        // TODO Auto-generated constructor stub
    }
    private ApplicationContext applicationContext; 
	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		HttpSession session=request.getSession();
		session.invalidate();
		response.sendRedirect("login.jsp");
	}
	public void init(ServletConfig config) throws ServletException { 
	       // TODO Auto-generatedmethod stub 
	    super.init(config); 
	    applicationContext=WebApplicationContextUtils.getRequiredWebApplicationContext(this.getServletContext());
	    demoService=(DemoService)applicationContext.getBean("demoService");
	} 
	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		HttpSession session=request.getSession();
		String username=request.getParameter("username");
		System.out.println(demoService.sayHello("testman"));
		session.setAttribute("user",username);
		response.sendRedirect("usr/index.jsp");
	}

}

WEB-INF\web.xml

 

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
  <display-name>casdemo</display-name>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.htm</welcome-file>
    <welcome-file>index.jsp</welcome-file>
    <welcome-file>default.html</welcome-file>
    <welcome-file>default.htm</welcome-file>
    <welcome-file>default.jsp</welcome-file>
  </welcome-file-list>
  
  <context-param>
 		<param-name>contextConfigLocation</param-name>
		<param-value>
		  WEB-INF/spring-servlet.xml,classpath*:webconsumer.xml
		</param-value>
  </context-param>
  <listener>
		<listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
  </listener>
  
  <filter>
    <filter-name>CheckLoginFilter</filter-name>
    <filter-class>casdemo.CheckLoginFilter</filter-class>
  </filter>
  <listener>
    <listener-class>casdemo.DebugSessionListener</listener-class>
  </listener>
  <servlet>
		<servlet-name>spring</servlet-name>
		<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
		<load-on-startup>1</load-on-startup>
	</servlet>
	<servlet-mapping>
		<servlet-name>spring</servlet-name>
		<url-pattern>*.do</url-pattern>
	</servlet-mapping>
  <servlet>
    	<servlet-name>login</servlet-name>
    	<servlet-class>casdemo.Login</servlet-class>
	</servlet>
  	<servlet-mapping>
    	<servlet-name>login</servlet-name>
    	<url-pattern>/login</url-pattern>
	</servlet-mapping>
  <filter-mapping>
    <filter-name>CheckLoginFilter</filter-name>
    <url-pattern>/usr/*</url-pattern>
  </filter-mapping>
</web-app>

WEB-INF\spring-servlet.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:mvc="http://www.springframework.org/schema/mvc" 
	   xmlns:aop="http://www.springframework.org/schema/aop" 
	   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/mvc
                           http://www.springframework.org/schema/mvc/spring-mvc.xsd
						   http://www.springframework.org/schema/aop
						   http://www.springframework.org/schema/aop/spring-aop.xsd
						   http://www.springframework.org/schema/context
						   http://www.springframework.org/schema/context/spring-context.xsd"
       default-lazy-init="true">
    <context:component-scan base-package="casdemo">
    	<context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
    </context:component-scan>
    
	
	<bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">
		<property name="maxUploadSize" value="20971520" />
	</bean>
	
	<bean class="org.springframework.http.converter.ByteArrayHttpMessageConverter">
		<property name="supportedMediaTypes">
			<list>
				<value>image/jpeg</value>
				<value>image/png</value>
				<value>image/svg+xml</value>
				<value>application/pdf</value>
			</list>
		</property>
	</bean>
		
</beans> 

测试

工程地址 ：https://code.csdn.net/wh0426/msmdemo/tree/master

访问 http://localhost:8080/casdemo/login.jsp 登录成功后，会在控制台日志中打印Hellotestman 。

 

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