05、品优购——Demo案例配置演示

水深无声 2022-05-12 21:14 269阅读 0赞

废话唠叨的不少了，接下来我们写个小demo实现一下吧！

一、项目创建步骤

1、创建工程（选择maven中的web工程）

![70][]

注意先提前配置好自己的maven仓库哦！

因为是两个服务间的调用，所以我们需要来创建两个服务，与第一个服务创建流程一样大家快动手创建一下吧！

2、创建子文件夹

![70 1][]

分别存放java文件以及相关配置文件。

3、配置pom文件

<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>cn.itcast.dubboxdemo</groupId>
      <artifactId>dubboxdemo-service</artifactId>
      <version>0.0.1-SNAPSHOT</version>
      <packaging>war</packaging>  
       <properties>		
    		<spring.version>4.2.4.RELEASE</spring.version>
       </properties>    
    	<dependencies>
    		
    		<dependency>
    			<groupId>org.springframework</groupId>
    			<artifactId>spring-context</artifactId>
    			<version>${spring.version}</version>
    		</dependency>
    		<dependency>
    			<groupId>org.springframework</groupId>
    			<artifactId>spring-beans</artifactId>
    			<version>${spring.version}</version>
    		</dependency>
    		<dependency>
    			<groupId>org.springframework</groupId>
    			<artifactId>spring-webmvc</artifactId>
    			<version>${spring.version}</version>
    		</dependency>
    		<dependency>
    			<groupId>org.springframework</groupId>
    			<artifactId>spring-jdbc</artifactId>
    			<version>${spring.version}</version>
    		</dependency>
    		<dependency>
    			<groupId>org.springframework</groupId>
    			<artifactId>spring-aspects</artifactId>
    			<version>${spring.version}</version>
    		</dependency>
    		<dependency>
    			<groupId>org.springframework</groupId>
    			<artifactId>spring-jms</artifactId>
    			<version>${spring.version}</version>
    		</dependency>
    		<dependency>
    			<groupId>org.springframework</groupId>
    			<artifactId>spring-context-support</artifactId>
    			<version>${spring.version}</version>
    		</dependency>	
    		
    		<dependency>
    			<groupId>com.alibaba</groupId>
    			<artifactId>dubbo</artifactId>
    			<version>2.8.4</version>			
    		</dependency>
    		<dependency>
    			<groupId>org.apache.zookeeper</groupId>
    			<artifactId>zookeeper</artifactId>
    			<version>3.4.6</version>
    		</dependency>
    		<dependency>
    			<groupId>com.github.sgroschupf</groupId>
    			<artifactId>zkclient</artifactId>
    			<version>0.1</version>
    		</dependency>		
    		<dependency>
    			<groupId>javassist</groupId>
    			<artifactId>javassist</artifactId>
    			<version>3.11.0.GA</version>
    		</dependency>		
    	</dependencies>
       <build>  
    	  <plugins>
    	      <plugin>  
    	          <groupId>org.apache.maven.plugins</groupId>  
    	          <artifactId>maven-compiler-plugin</artifactId>  
    	          <version>2.3.2</version>  
    	          <configuration>  
    	              <source>1.7</source>  
    	              <target>1.7</target>  
    	          </configuration>  
    	      </plugin>  
    	      <plugin>
    				<groupId>org.apache.tomcat.maven</groupId>
    				<artifactId>tomcat7-maven-plugin</artifactId>
    				<configuration>
    					
    					<port>8081</port>
    					
    					<path>/</path>
    				</configuration>
    	  	  </plugin>
    	  </plugins>  
        </build>
    </project>

4、配置对应的tomcat

![70 2][]

5、配置服务提供者web.xml

**在工程的webapps下创建WEB-INF文件夹，创建web.xml**

6、服务提供者dubbo配置文件

在src/main/resources下创建applicationContext-service.xml ,内容如下：

<?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:p="http://www.springframework.org/schema/p"
    	xmlns:context="http://www.springframework.org/schema/context"
    	xmlns:dubbo="http://code.alibabatech.com/schema/dubbo" xmlns:mvc="http://www.springframework.org/schema/mvc"
    	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://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd
            http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
         
    	<dubbo:application name="dubboxdemo-service"/>  
    <dubbo:registry address="zookeeper://192.168.200.128:2181"/> 
    <dubbo:annotation package="cn.itcast.dubboxdemo.service" /> 
    </beans>

注意：dubbo:annotation用于扫描@Service注解。

7、服务提供者代码

**创建业务接口**

创建包cn.itcast.dubbodemo.service，用于存放业务接口，创建接口

package cn.itcast.dubbodemo.service;
    /**
     * 业务接口
     * @author Administrator
     *
     */
    public interface UserService {	
    	public String getName();	
    }

**创建业务实现类**

创建包cn.itcast.dubbodemo.service.impl ，用于存放业务实现类。创建业务实现类：

package cn.itcast.dubbodemo.service.impl;
    import com.alibaba.dubbo.config.annotation.Service;
    import cn.itcast.dubbodemo.service.UserService;
    @Service
    public class UserServiceImpl implements UserService {
    	public String getName() {		
    		return "itcast";
    	}
    }

注意：Service注解与原来不同，需要引入com.alibaba包下的

**测试运行**

tomcat7:run

8、服务消费者pom

**创建Maven工程（WAR）dubboxdemo-web, war项目** ，在pom.xml引入依赖 ，同“dubboxdemo-service”工程。区别就是把tomcat插件的运行端口改为8082 。

9、服务消费者web.xml

**在webapps目录下创建WEB-INF 目录**，并创建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">	
       
    	<filter>
    		<filter-name>CharacterEncodingFilter</filter-name>		<filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
    		<init-param>
    			<param-name>encoding</param-name>
    			<param-value>utf-8</param-value>
    		</init-param>
    		<init-param>  
                <param-name>forceEncoding</param-name>  
                <param-value>true</param-value>  
            </init-param>  
    	</filter>
    	<filter-mapping>
    		<filter-name>CharacterEncodingFilter</filter-name>
    		<url-pattern>/*</url-pattern>
    	</filter-mapping>		
      <servlet>
      	<servlet-name>springmvc</servlet-name>  	<servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
      	
      	<init-param>
      		<param-name>contextConfigLocation</param-name>
      		<param-value>classpath:applicationContext-web.xml</param-value>
      	</init-param>
      </servlet>  
      <servlet-mapping>
      	<servlet-name>springmvc</servlet-name>
      	<url-pattern>*.do</url-pattern>
      </servlet-mapping>
    </web-app>

10、服务消费者dubbo配置文件

**编写spring配置文件**

在src/main/resources下创建applicationContext-web.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:p="http://www.springframework.org/schema/p"
    	xmlns:context="http://www.springframework.org/schema/context"
    	xmlns:dubbo="http://code.alibabatech.com/schema/dubbo" xmlns:mvc="http://www.springframework.org/schema/mvc"
    	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://code.alibabatech.com/schema/dubbo http://code.alibabatech.com/schema/dubbo/dubbo.xsd
            http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
    
    	<mvc:annotation-driven >
    		<mvc:message-converters register-defaults="false">
    			<bean class="org.springframework.http.converter.StringHttpMessageConverter">  
    				<constructor-arg value="UTF-8" />
    			</bean>  
    		</mvc:message-converters>	
    	</mvc:annotation-driven>
    	
    	<dubbo:application name="dubboxdemo-web" />
    	<dubbo:registry address="zookeeper://192.168.200.128:2181"/>
         <dubbo:annotation package="cn.itcast.dubboxdemo.controller" />
    </beans>

11、服务消费者代码

**拷贝业务接口**

将“dubboxdemo-service”工程的cn.itcast.dubboxdemo.service 包以及下面的接口拷贝至此工程。

编写Controller

package cn.itcast.dubboxdemo.controller;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.stereotype.Controller;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.ResponseBody;
    import cn.itcast.dubbodemo.service.UserService;
    @Controller
    @RequestMapping("/user")
    public class UserController {
    	@Reference
    	private UserService userService;	
    	@RequestMapping("/showName")
    	@ResponseBody
    	public String showName(){
    		return userService.getName();
    	}		
    }

**测试运行**

tomcat7:run

在浏览器输入http://localhost:8082/user/showName.do，查看浏览器输出结果

12、常见错误

1、在注册中心找不到自己的服务

java.lang.IllegalStateException: Failed to check the status of the service com.pinyougou.sellergoods.service.BrandService. No provider available for the service com.pinyougou.sellergoods.service.BrandService from the url zookeeper://192.168.25.129:2181/com.alibaba.dubbo.registry.RegistryService?application=pinyougou-manager-web&dubbo=2.8.4&interface=com.pinyougou.sellergoods.service.BrandService&methods=update,get,delete,selectOptionList,add,getListByPage&pid=3980&revision=0.0.1-SNAPSHOT&side=consumer&timestamp=1501146823396 to the consumer 172.16.17.14 use dubbo version 2.8.4

这种错误是服务层代码没有成功注册到注册中心导致，请检查一下你的服务层代码是否添加了@service注解，并且该注解的包一定是com.alibaba.dubbo.config.annotation包，不是org.springframework.stereotype.Service，这个地方极容易出错。另外还有一个原因就是你的服务层工程由于某些原因没有正常启动，也无法注册到注册中心里。

2、无法连接到注册中心

org.I0Itec.zkclient.exception.ZkTimeoutException: Unable to connect to zookeeper server within timeout: 5000	org.I0Itec.zkclient.ZkClient.connect(ZkClient.java:876)	org.I0Itec.zkclient.ZkClient.<init>(ZkClient.java:98)	org.I0Itec.zkclient.ZkClient.<init>(ZkClient.java:92)	org.I0Itec.zkclient.ZkClient.<init>(ZkClient.java:80)
    	com.alibaba.dubbo.remoting.zookeeper.zkclient.ZkclientZookeeperClient.<init>(ZkclientZookeeperClient.java:26)

请检查IP与端口是否填写正确，检查注册中心是否正常启动

以上，就是我们的小demo的全部内容了，怎么样可以完整执行吗？

[70]: /images/20220513/6489ee23641b447594d5e0756d041539.png
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