写在前面
如果你已经看到这里了,说明你可能正在写 dubbo 入门案例,但是好像一直在出错,我也是如此,我发现,入门案例中如果你已经理顺了 dubbo 大概逻辑的情况下大多数错误其实是 maven 依赖起了冲突,你可以自己使用 maven helper 插件进行排查。
dubbo 入门案例
首先理清 dubbo 的运行逻辑,以下先理清逻辑,配置文件后续给出:
-
启动 provider
- provider 提供服务,需要暴露对应接口,暴露之后需要指定对应的实现类。
- 需要指定暴露服务的端口,这个默认是 20880,但是如果你使用多个 provider 的情况下需要注意,不同 provider 必须使用不同的暴露服务的端口
-
启动 consumer
- provider 将服务注册到 zookeeper 这类的注册中心后,consumer 就可以接入注册中心,注意必须指定你想要监听的引用,也即 provider 暴露的服务
案例
因为 dubbo 本身也推荐分包处理,所以会将有关接口和实体类放到一个 api 包下,接下来的业务逻辑:
- 有一个用户地址实体类,存储用户地址等信息。
- userService 提供接口以及实现类返回对应 id 的地址类
- orderService 会通过 dubbo 调用 userService 的对应方法,并获取信息
api 模块结构:
UserAddress.class 实体类
package edu.hour.pojo;
import java.io.Serializable;
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(Integer id, String userAddress, String userId, String consignee, String phoneNum, String isDefault) {
this.id = id;
this.userAddress = userAddress;
this.userId = userId;
this.consignee = consignee;
this.phoneNum = phoneNum;
this.isDefault = isDefault;
}
}
UserService.class
package edu.hour.service;
import edu.hour.pojo.UserAddress;
import java.util.List;
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);
}
provider 模块结构:
服务者提供接口的实现类
public class DemoServiceImpl implements DemoService {
@Override
public String sayHello(String name) {
return "Hello " + name;
}
}
provider.class
public class Provider {
public static void main(String[] args) throws Exception {
ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("classpath:dubbo-provider.xml");
context.start();
System.in.read(); // 按任意键退出
}
}
consumer 模块结构:
OrderService.class 接口
public interface OrderService {
/**
* 初始化订单
* @param userID
*/
public void initOrder(String userID);
}
OrderServiceImpl.class 实现类
@Service
public class OrderServiceImpl implements OrderService {
@Autowired
public UserService userService;
public void initOrder(String userID) {
//查询用户的收货地址
List<UserAddress> userAddressList = userService.getUserAddressList(userID);
//为了直观的看到得到的数据,以下内容也可不写
System.out.println("当前接收到的userId=> "+userID);
System.out.println("**********");
System.out.println("查询到的所有地址为:");
for (UserAddress userAddress : userAddressList) {
//打印远程服务地址的信息
System.out.println(userAddress.toString());
}
}
}
Consumer
public class Consumer {
public static void main(String[] args) throws IOException {
ClassPathXmlApplicationContext applicationContext = new ClassPathXmlApplicationContext("classpath:dubbo-consumer.xml");
OrderService orderService = applicationContext.getBean(OrderService.class);
//调用方法查询出数据
orderService.initOrder("1");
System.out.println("调用完成...");
System.in.read();
}
}
配置类
以下会先将逻辑列出,可先自己实现,如有错误,还望指出:
dubbo-provider.xml
- 需要一个可识别的唯一名称
- 需要指定注册中心地址以及端口,以及对应的协议,因为不同的注册中心支持不同的协议
- 暴露本地端口接收 dubbo,默认为 20880
- 声明需要暴露的接口,以及对应的实现类
dubbo-consumer.xml
- 需要一个可识别的唯一名称
- 需要指定注册中心地址以及端口
- 生成远程服务代理,可以和本地bean一样使用demoService
dubbo-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://dubbo.apache.org/schema/dubbo"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd http://dubbo.apache.org/schema/dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd">
<!-- 提供方应用信息,用于计算依赖关系 -->
<dubbo:application name="provider-app" />
<!-- 使用zookeeper注册中心暴露服务地址 -->
<dubbo:registry protocol="zookeeper" address="zookeeper://110.41.140.53:2181" />
<!-- 使用随机端口暴露服务,防止和本地其他服务冲突 -->
<dubbo:protocol name="dubbo" port="20880" />
<!-- 声明需要暴露的服务接口 -->
<dubbo:service interface="com.yuqiao.deeplearningdubbo.demo.api.DemoService" ref="demoService" />
<!-- 和本地bean一样实现服务 -->
<bean id="demoService" class="com.yuqiao.deeplearningdubbo.demo.provider.DemoServiceImpl" />
</beans>
provider-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"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.3.xsd http://dubbo.apache.org/schema/dubbo http://dubbo.apache.org/schema/dubbo/dubbo.xsd">
<!-- 消费方应用名 -->
<dubbo:application name="consumer-app" />
<!-- 使用zookeeper注册中心发现服务 -->
<dubbo:registry address="zookeeper://110.41.140.53:2181" />
<!-- 生成远程服务代理,可以和本地bean一样使用demoService -->
<dubbo:reference id="demoService" interface="com.yuqiao.deeplearningdubbo.demo.api.DemoService" timeout="1000" retries="0" />
</beans>
pom 文件不太想进行拆分了,反正只要不会依赖冲突,加多一些没问题:
consumer:
<?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.yuqiao.deeplearningdubbo</groupId>
<artifactId>dubbo_demo_consumer</artifactId>
<version>1.0-SNAPSHOT</version>
<name>dubbo_demo_consumer</name>
<!-- FIXME change it to the project's website -->
<url>http://www.example.com</url>
<properties>
<spring.version>4.1.9.RELEASE</spring.version>
</properties>
<dependencies>
<dependency>
<groupId>com.yuqiao.deeplearningdubbo</groupId>
<artifactId>dubbo_demo_api</artifactId>
<version>1.0-SNAPSHOT</version>
</dependency>
<dependency>
<groupId>io.netty</groupId>
<artifactId>netty-all</artifactId>
<version>4.1.59.Final</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.dubbo/dubbo -->
<dependency>
<groupId>org.apache.dubbo</groupId>
<artifactId>dubbo</artifactId>
<version>2.7.4.1</version>
</dependency>
<dependency>
<groupId>com.101tec</groupId>
<artifactId>zkclient</artifactId>
<version>0.4</version>
</dependency>
<!--spring-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
<version>${spring.version}</version>
</dependency>
<!--spring web mvc-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
<version>3.4.9</version>
</dependency>
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-recipes</artifactId>
<version>4.2.0</version>
</dependency>
</dependencies>
</project>
provider.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.yuqiao.deeplearningdubbo</groupId>
<artifactId>dubbo_demo_provider</artifactId>
<version>1.0-SNAPSHOT</version>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>6</source>
<target>6</target>
</configuration>
</plugin>
</plugins>
</build>
<name>dubbo_demo_provider</name>
<!-- FIXME change it to the project's website -->
<url>http://www.example.com</url>
<properties>
<spring.version>4.1.9.RELEASE</spring.version>
</properties>
<dependencies>
<dependency>
<groupId>com.yuqiao.deeplearningdubbo</groupId>
<artifactId>dubbo_demo_api</artifactId>
<version>1.0-SNAPSHOT</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.apache.dubbo/dubbo -->
<dependency>
<groupId>org.apache.dubbo</groupId>
<artifactId>dubbo</artifactId>
<version>2.7.8</version>
</dependency>
<!--spring-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-core</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-context-support</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-beans</artifactId>
<version>${spring.version}</version>
</dependency>
<!--spring web mvc-->
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${spring.version}</version>
</dependency>
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-framework</artifactId>
<version>2.8.0</version>
</dependency>
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-recipes</artifactId>
<version>2.8.0</version>
</dependency>
</dependencies>
</project>
标签:dubbo,String,spring,案例,provider,org,public,入门
From: https://www.cnblogs.com/demoy/p/16890517.html