环境安装
Dubbo使用zookeeper作为注册中心,首先要安装zookeeper。
Windows安装zookeeper如下:
https://blog.csdn.net/qq_33316784/article/details/88563482
Linux安装zookeeper如下:
https://www.cnblogs.com/expiator/p/9853378.html
SpringBoot新建项目
如果还不清楚怎么新建SpringBoot项目,可以参考: https://www.cnblogs.com/expiator/p/15844275.html
服务提供者Dubbo-provider
创建了dubbo-provider模块,作为服务提供者。
dubbo有多种groupId,其中的org.apache.dubbo的版本,比较适合SpringBoot2.X,注解不会过期或者失效。
引入 org.apache.dubbo 的包,dubbo的版本号设置在 2.7.5 。
pom.xml如下:
<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.example</groupId>
<artifactId>dubbo-provider</artifactId>
<version>1.0-SNAPSHOT</version>
<name>dubbo-provider</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<spring-boot.version>2.2.2.RELEASE</spring-boot.version>
<dubbo.version>2.7.5</dubbo.version>
<curator.version>4.2.0</curator.version>
<zookeeper.version>3.4.12</zookeeper.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!-- dubbo,注意要使用 org.apache.dubbo的groupId -->
<dependency>
<groupId>org.apache.dubbo</groupId>
<artifactId>dubbo-spring-boot-starter</artifactId>
<version>${dubbo.version}</version>
</dependency>
<!-- zookeeper依赖 -->
<dependency>
<groupId>org.apache.zookeeper</groupId>
<artifactId>zookeeper</artifactId>
<version>${zookeeper.version}</version>
</dependency>
<!-- zookeeper的api管理依赖 -->
<dependency>
<groupId>org.apache.curator</groupId>
<artifactId>curator-recipes</artifactId>
<version>${curator.version}</version>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-dependencies</artifactId>
<version>${spring-boot.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.1</version>
<configuration>
<source>1.8</source>
<target>1.8</target>
<encoding>UTF-8</encoding>
</configuration>
</plugin>
</plugins>
</build>
</project>
application.yml
在resources文件下添加 application.yml,配置如下:
dubbo:
application:
# 应用名称
name: dubbo-provider
protocol:
# 协议名称
name: dubbo
# 协议端口
port: 20880
registry:
# 注册中心地址
address: zookeeper://127.0.0.1:2181
server:
# 修改端口号,避免端口冲突
port: 8081
pojo类:
@Data 是 lombok注解,相当于getter、setter、toString等方法。
@NoArgsConstructor也是 是 lombok注解,相当于没有参数的构造方法。
@AllArgsConstructor 是包含所有参数的构造方法。
如果不用lombok,也可以自行替换成相应的方法。
@Data
@NoArgsConstructor
@AllArgsConstructor
public class User implements Serializable {
private static final long serialVersionUID = -4294369157631461921L;
Long userId;
String userName;
String userInfo;
}
service:
public interface UserService {
String getUserInfo();
User getUserById(String userId);
}
service实现类:
注意,@service注解,引入的包是org.apache.dubbo.config.annotation.Service
import org.apache.dubbo.config.annotation.Service;
import org.springframework.stereotype.Component;
/**
* 注意,@service注解,引入的包是org.apache.dubbo.config.annotation.Service
*/
@Service
@Component
public class UserServiceImpl implements UserService {
@Override
public String getUserInfo() {
return "userTest";
}
@Override
public User getUserById(String userId) {
User user = new User();
user.setUserId(Long.valueOf(userId));
user.setUserInfo("test");
user.setUserName("lin");
return user;
}
}
SpringBoot启动类:
注意:
/**
* 提供服务的应用配置DubboComponentScan注解,指定扫描的service所在的文件
*/
@SpringBootApplication
@DubboComponentScan("com.example.service")
public class DubboProviderApplication {
public static void main(String[] args) {
SpringApplication.run(DubboProviderApplication.class, args);
}
}
install服务提供者dubbo-provider
在idea中,对服务提供者dubbo-provider的依赖, 用Maven执行clean,并install到Maven仓库,就可以提供给其他模块使用。
服务消费者 dubbo-consumer
新建一个服务消费者 dubbo-consumer的maven项目。
pom.xml
pom.xml中,服务消费者 dubbo-consumer 的依赖跟之前的类似,只是还要引入服务提供者dubbo-provider的依赖,这样才能调用其中的Service。
<!-- 引入服务提供者的依赖,注意版本号 -->
<dependency>
<groupId>com.example</groupId>
<artifactId>dubbo-provider</artifactId>
<version>1.0-SNAPSHOT</version>
</dependency>
application.yml
类似 dubbo-provider, 可以将端口号修改为 8082,避免端口号冲突
ConsumerController 类:
import com.example.pojo.User;
import com.example.service.UserService;
import org.apache.dubbo.config.annotation.Reference;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
@RequestMapping("/user")
public class ConsumerController {
/**
* 通过 @Reference注解调用远程服务,也就是服务提供者dubbo-provider的服务
*/
@Reference
private UserService userService;
@GetMapping("/info")
public String getUserById() {
return userService.getUserInfo();
}
@GetMapping("/{id}")
public User getUserById(@PathVariable String id) {
return userService.getUserById(id);
}
}
DubboConsumerApplication启动类:
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
public class DubboConsumerApplication {
public static void main(String[] args) {
SpringApplication.run(DubboConsumerApplication.class, args);
}
}
启动项目
- 首先启动zookeeper .
Windows安装和启动zookeeper如下:
https://blog.csdn.net/qq_33316784/article/details/88563482
Linux安装和启动zookeeper如下:
https://www.cnblogs.com/expiator/p/9853378.html
没有启动 zookeeper会报错:
Caused by: java.lang.IllegalStateException: zookeeper not connected
at org.apache.dubbo.remoting.zookeeper.curator.CuratorZookeeperClient.<init>(CuratorZookeeperClient.java:80) ~[dubbo-2.7.5.jar:2.7.5]
... 32 common frames omitted
-
端口号被占用,需要修改端口号,否则会报错。
Web server failed to start. Port 8080 was already in use.
Action:
Identify and stop the process that's listening on port 8080 or configure this application to listen on another port. -
启动报错:
Whitelabel Error Page
This application has no explicit mapping for /error, so you are seeing this as a fallback.
解决方法:https://www.cnblogs.com/expiator/p/15837518.html
- 先启动Provider,再启动Consumer
启动成功如下:
- 打开浏览器,访问ConsumerController的接口
注意,使用的端口号是服务消费者的端口号。
http://localhost:8082/user/123