一、dubbo hello world入门示例
1、提出需求
某个电商系统，订单服务需要调用用户服务获取某个用户的所有地址；
我们现在需要创建两个服务模块进行测试：
| 模块 |
功能 |
| 订单服务web模块 |
创建订单等 |
| 用户服务service模块 |
查询用户地址等 |
测试预期结果：订单服务web模块在A服务器，用户服务模块在B服务器，A可以远程调用B的功能。
2、工程结构
根据 dubbo《服务化最佳实践》
a、分包
建议将服务接口，服务模型，服务异常等均放在 API 包中，因为服务模型及异常也是 API 的一部分，同时，这样做也符合分包原则：重用发布等价原则(REP)，共同重用原则(CRP)。
如果需要，也可以考虑在 API 包中放置一份 spring 的引用配置，这样使用方，只需在 spring 加载过程中引用此配置即可，配置建议放在模块的包目录下，以免冲突，如：com/alibaba/china/xxx/dubbo-reference.xml。
b、粒度
服务接口尽可能大粒度，每个服务方法应代表一个功能，而不是某功能的一个步骤，否则将面临分布式事务问题，Dubbo 暂未提供分布式事务支持。服务接口建议以业务场景为单位划分，并对相近业务做抽象，防止接口数量爆炸。
不建议使用过于抽象的通用接口，如：Map query(Map)，这样的接口没有明确语义，会给后期维护带来不便。
二、创建工程
1、创建project、module
本demo采用project以及多module的方式，project叫dubbo，module分别为gmall-interface、order-service-consumer、user-service-providor，如图：
a、父project
pom.xml
<?xml version="1.0" encoding="UTF-8"?> <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.ty</groupId> <artifactId>dubbo</artifactId> <packaging>pom</packaging> <version>1.0-SNAPSHOT</version> <modules> <module>gmall-interface</module> <module>order-service-consumer</module> <module>user-service-providor</module> </modules> <!--如果不指定可能会报一个错误，@Override is not allowed when implementing interface method--> <build> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>3.1</version> <configuration> <source>1.8</source> <target>1.8</target> </configuration> </plugin> </plugins> </build> </project>
b、公共接口层(gmall-interface)
结构如图：
pom.xml
<?xml version="1.0" encoding="UTF-8"?> <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"> <parent> <artifactId>dubbo</artifactId> <groupId>com.ty</groupId> <version>1.0-SNAPSHOT</version> </parent> <modelVersion>4.0.0</modelVersion> <artifactId>gmall-interface</artifactId> </project>
UserAddress
package com.ty.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; } }
OrderService
package com.ty.service; import com.ty.bean.UserAddress; import java.util.List; public interface OrderService { /** * 初始化订单 * @param userId */ public List<UserAddress> initOrder(String userId); }
UserService
package com.ty.service; import com.ty.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); }
c、user-service-providor
pom.xml
<?xml version="1.0" encoding="UTF-8"?> <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"> <parent> <artifactId>dubbo</artifactId> <groupId>com.ty</groupId> <version>1.0-SNAPSHOT</version> </parent> <modelVersion>4.0.0</modelVersion> <artifactId>user-service-providor</artifactId> <dependencies> <dependency> <groupId>com.ty</groupId> <artifactId>gmall-interface</artifactId> <version>1.0-SNAPSHOT</version> </dependency> <!-- 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> </dependencies> </project>
UserServiceImpl
package com.ty.service.impl; import com.ty.bean.UserAddress; import com.ty.service.UserService; import java.util.Arrays; import java.util.List; public class UserServiceImpl implements UserService { @Override 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); } }
UserServiceImpl2
package com.ty.service.impl; import com.ty.bean.UserAddress; import com.ty.service.UserService; import java.util.Arrays; import java.util.List; public class UserServiceImpl2 implements UserService { @Override public List<UserAddress> getUserAddressList(String userId) { System.out.println("UserServiceImpl.....new..."); // 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"); return Arrays.asList(address1,address2); } }
UserServiceStub
package com.ty.service.impl; import com.ty.bean.UserAddress; import com.ty.service.UserService; import org.springframework.util.StringUtils; import java.util.List; public class UserServiceStub implements UserService { private final UserService userService; /** * 传入的是userService远程的代理对象 * @param userService */ public UserServiceStub(UserService userService) { super(); this.userService = userService; } @Override public List<UserAddress> getUserAddressList(String userId) { // TODO Auto-generated method stub System.out.println("UserServiceStub....."); if(!StringUtils.isEmpty(userId)) { return userService.getUserAddressList(userId); } return null; } }
MainApplication
package com.ty; import org.springframework.context.support.ClassPathXmlApplicationContext; import java.io.IOException; public class MainApplication { public static void main(String[] args) throws IOException { ClassPathXmlApplicationContext ioc = new ClassPathXmlApplicationContext("provider.xml"); ioc.start(); System.in.read(); } }
providor.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="20882"></dubbo:protocol> <!-- 4、暴露服务 ref：指向服务的真正的实现对象 --> <dubbo:service interface="com.ty.service.UserService" ref="userServiceImpl01" timeout="1000" version="1.0.0"> <dubbo:method name="getUserAddressList" timeout="1000"></dubbo:method> </dubbo:service> <!--统一设置服务提供方的规则 --> <dubbo:provider timeout="1000"></dubbo:provider> <!-- 服务的实现 --> <bean id="userServiceImpl01" class="com.ty.service.impl.UserServiceImpl"></bean> <dubbo:service interface="com.ty.service.UserService" ref="userServiceImpl02" timeout="1000" version="2.0.0"> <dubbo:method name="getUserAddressList" timeout="1000"></dubbo:method> </dubbo:service> <bean id="userServiceImpl02" class="com.ty.service.impl.UserServiceImpl2"></bean> <!-- 连接监控中心 --> <dubbo:monitor protocol="registry"></dubbo:monitor> </beans>
d、order-service-consumer
pom.xml
<?xml version="1.0" encoding="UTF-8"?> <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"> <parent> <artifactId>dubbo</artifactId> <groupId>com.ty</groupId> <version>1.0-SNAPSHOT</version> </parent> <modelVersion>4.0.0</modelVersion> <artifactId>order-service-consumer</artifactId> <dependencies> <dependency> <groupId>com.ty</groupId> <artifactId>gmall-interface</artifactId> <version>1.0-SNAPSHOT</version> </dependency> <!-- 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> </dependencies> </project>
OrderServiceImpl
package com.ty.service.impl; import com.ty.bean.UserAddress; import com.ty.service.OrderService; import com.ty.service.UserService; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Service; import java.util.List; /** * 1、将服务提供者注册到注册中心（暴露服务） * 1）、导入dubbo依赖（2.6.2）\操作zookeeper的客户端(curator) * 2）、配置服务提供者 * * 2、让服务消费者去注册中心订阅服务提供者的服务地址 * @author lfy * */ @Service public class OrderServiceImpl implements OrderService { @Autowired UserService userService; @Override public List<UserAddress> initOrder(String userId) { // TODO Auto-generated method stub System.out.println("用户id："+userId); //1、查询用户的收货地址 List<UserAddress> addressList = userService.getUserAddressList(userId); for (UserAddress userAddress : addressList) { System.out.println(userAddress.getUserAddress()); } return addressList; } }
MainApplication
package com.ty; import com.ty.service.OrderService; import org.springframework.context.support.ClassPathXmlApplicationContext; import java.io.IOException; 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(); } }
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.ty.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.ty.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>
三、测试
1、启动zooker的服务以及上篇博文中的dubbo-admin(java -jar的方式启动)
2、启动user-service-providor的MainApplication中的main方法
E:\jdk\bin\java.exe "-javaagent:E:\utils\Intellij idea\IntelliJ IDEA 2018.3.2\lib\idea_rt.jar=51328:E:\utils\Intellij idea\IntelliJ IDEA 2018.3.2\bin" -Dfile.encoding=UTF-8 -classpath E:\jdk\jre\lib\charsets.jar;E:\jdk\jre\lib\deploy.jar;E:\jdk\jre\lib\ext\access-bridge-64.jar;E:\jdk\jre\lib\ext\cldrdata.jar;E:\jdk\jre\lib\ext\dnsns.jar;E:\jdk\jre\lib\ext\jaccess.jar;E:\jdk\jre\lib\ext\jfxrt.jar;E:\jdk\jre\lib\ext\localedata.jar;E:\jdk\jre\lib\ext\nashorn.jar;E:\jdk\jre\lib\ext\sunec.jar;E:\jdk\jre\lib\ext\sunjce_provider.jar;E:\jdk\jre\lib\ext\sunmscapi.jar;E:\jdk\jre\lib\ext\sunpkcs11.jar;E:\jdk\jre\lib\ext\zipfs.jar;E:\jdk\jre\lib\javaws.jar;E:\jdk\jre\lib\jce.jar;E:\jdk\jre\lib\jfr.jar;E:\jdk\jre\lib\jfxswt.jar;E:\jdk\jre\lib\jsse.jar;E:\jdk\jre\lib\management-agent.jar;E:\jdk\jre\lib\plugin.jar;E:\jdk\jre\lib\resources.jar;E:\jdk\jre\lib\rt.jar;E:\workspaceidea\dubbo\user-service-providor\target\classes;E:\workspaceidea\dubbo\gmall-interface\target\classes;E:\respository\com\alibaba\dubbo\2.6.2\dubbo-2.6.2.jar;E:\respository\org\springframework\spring-context\4.3.16.RELEASE\spring-context-4.3.16.RELEASE.jar;E:\respository\org\springframework\spring-aop\4.3.16.RELEASE\spring-aop-4.3.16.RELEASE.jar;E:\respository\org\springframework\spring-beans\4.3.16.RELEASE\spring-beans-4.3.16.RELEASE.jar;E:\respository\org\springframework\spring-core\4.3.16.RELEASE\spring-core-4.3.16.RELEASE.jar;E:\respository\commons-logging\commons-logging\1.2\commons-logging-1.2.jar;E:\respository\org\springframework\spring-expression\4.3.16.RELEASE\spring-expression-4.3.16.RELEASE.jar;E:\respository\org\javassist\javassist\3.20.0-GA\javassist-3.20.0-GA.jar;E:\respository\org\jboss\netty\netty\3.2.5.Final\netty-3.2.5.Final.jar;E:\respository\org\apache\curator\curator-framework\2.12.0\curator-framework-2.12.0.jar;E:\respository\org\apache\curator\curator-client\2.12.0\curator-client-2.12.0.jar;E:\respository\org\apache\zookeeper\zookeeper\3.4.8\zookeeper-3.4.8.jar;E:\respository\log4j\log4j\1.2.16\log4j-1.2.16.jar;E:\respository\jline\jline\0.9.94\jline-0.9.94.jar;E:\respository\io\netty\netty\3.7.0.Final\netty-3.7.0.Final.jar;E:\respository\com\google\guava\guava\16.0.1\guava-16.0.1.jar;E:\respository\org\slf4j\slf4j-api\1.7.6\slf4j-api-1.7.6.jar com.ty.MainApplication log4j:WARN No appenders could be found for logger (org.springframework.core.env.StandardEnvironment). log4j:WARN Please initialize the log4j system properly. log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info. SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder". SLF4J: Defaulting to no-operation (NOP) logger implementation SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details.
3、打开http://localhost:7001/
可以看到已经有两个服务了，说明user-service-providor启动ok
4、测试order-service-consumer(运行其main方法)
用户id：1
北京市昌平区宏福科技园综合楼3层
深圳市宝安区西部硅谷大厦B座3层（深圳分校）
调用完成....
说明消费方也调用成功
dubbo hello world已上传github：https://github.com/ali-mayun/dubbo