SpringCloud Alibaba + Dubbo + Nacos 框架实例

前言

我一共搭建了3个环境。
整体入口：
https://blog.csdn.net/lwb314/article/details/108222433

注意事项

1. 这次使用的依赖是spring-cloud-starter-dubbo，这个我在git上没搜到，最后我发现他是spring-cloud-alibaba下的，spring-cloud-starter下的子项目，maven仓库里也找了一会才找到的，这个jar其实依赖的 例子2 里的dubbo-spring-boot-starter，所以这个例子应该跟例子2差不多
2. 个人觉得还是使用这个例子3的比较靠谱，都知道在spring cloud家族里现在有个spring cloud alibaba,使用的是一套阿里的技术方案，性能跟高，使用也更方便，我个人肯定是拥抱阿里，虽然阿里内部用的也不是这套开源技术╮(╯▽╰)╭无奈。不过毕竟像国外这些开源android,apache,spring这些东西可能用着用着就不让用了，呵呵。

代码

快速搭建

我的开发工具是IDEA，使用的是快速构建项目的Spring Initializr，前两个项目也是这么构建的，为什么要在这里单独提一下，因为这里必须要用阿里云快速构建，而不是用默认的spring快速构建，阿里云的构建地址是http://start.aliyun.com
具体看图

这页没啥说了，去个工程名，选下jdk版本

这一步一共有3个要注意的点，我已经圈出来了
第一个dubbo依赖，这个只有在阿里云里可以搜到，在spring里搜不到，所以第一张图必须选阿里云；第2个是版本使用spring boot 2.2这个大版，第3个是我已经选好的2个依赖一个是spring boot web ,一个是nacos依赖，最后再把dubbo这个依赖选上就完成了。

依赖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 https://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.lwb</groupId> <artifactId>spring-cloud-alibaba-dubbo-provider</artifactId> <version>0.0.1-SNAPSHOT</version> <name>spring-cloud-alibaba-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>2.2.7.RELEASE</spring-boot.version> <spring-cloud-alibaba.version>2.2.1.RELEASE</spring-cloud-alibaba.version> </properties> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <!--        <dependency>--> <!--            <groupId>org.springframework.boot</groupId>--> <!--            <artifactId>spring-boot-starter-actuator</artifactId>--> <!--        </dependency>--> <dependency> <groupId>com.alibaba.cloud</groupId> <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId> </dependency> <dependency> <groupId>com.alibaba.cloud</groupId> <artifactId>spring-cloud-starter-dubbo</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> <exclusions> <exclusion> <groupId>org.junit.vintage</groupId> <artifactId>junit-vintage-engine</artifactId> </exclusion> </exclusions> </dependency> </dependencies> <dependencyManagement> <dependencies> <dependency> <groupId>com.alibaba.cloud</groupId> <artifactId>spring-cloud-alibaba-dependencies</artifactId> <version>${spring-cloud-alibaba.version}</version> <type>pom</type> <scope>import</scope> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-dependencies</artifactId> <version>${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> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> <version>2.2.7.RELEASE</version> <configuration> <mainClass>com.lwb.springcloudalibabadubboprovider.SpringCloudAlibabaDubboProviderApplication </mainClass> </configuration> <executions> <execution> <id>repackage</id> <goals> <goal>repackage</goal> </goals> </execution> </executions> </plugin> </plugins> </build> </project> 

服务生产者代码-provider

application.properties

server.port=8003 spring.application.name=alibabadubboprovider
dubbo.application.id=alibabadubboprovider
dubbo.application.name=alibabadubboprovider
# 禁用QOS同一台机器可能会有端口冲突现象
dubbo.application.qos-enable=false dubbo.application.qos-accept-foreign-ip=false # 配置注册中心
dubbo.registry.address=nacos://10.10.171.249:8848 spring.cloud.nacos.discovery.server-addr=10.10.171.249:8848 dubbo.protocol.name=dubbo
dubbo.protocol.port=20883 dubbo.protocol.id=dubbo 

启动类

import org.apache.dubbo.config.spring.context.annotation.EnableDubbo; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; @EnableDubbo @SpringBootApplication public class SpringCloudAlibabaDubboProviderApplication { public static void main(String[] args) { SpringApplication.run(SpringCloudAlibabaDubboProviderApplication.class, args); } } 

服务实现类

@Service(version = "1.0.2",group = "lwb") public class DubboDemoServiceImpl implements DubboDemoService { @Override public String helloDubbo() { return "helloDubboAlibaba"; } } 

服务接口

public interface DubboDemoService { public String helloDubbo(); } 

服务消费者代码-consumer

package com.lwb.springcloudalibabadubboconsumer; import com.lwb.DubboDemoService; import org.apache.dubbo.config.annotation.Reference; import org.apache.dubbo.config.spring.context.annotation.EnableDubbo; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import javax.annotation.PostConstruct; @EnableDubbo @SpringBootApplication public class SpringCloudAlibabaDubboConsumerApplication { @Reference(version = "1.0.2", check = false, group = "lwb") private DubboDemoService demoService; @PostConstruct public void init() { String a = demoService.helloDubbo(); System.out.println(a); } public static void main(String[] args) { SpringApplication.run(SpringCloudAlibabaDubboConsumerApplication.class, args); } } 

application.properties

server.port=8004 # 禁用QOS同一台机器可能会有端口冲突现象
spring.application.name=dubbo-starter-consumer
dubbo.application.name=dubbo-starter-consumer
dubbo.application.id=dubbo-starter-consumer
dubbo.application.qos-enable=false dubbo.application.qos-accept-foreign-ip=false # 配置注册中心
dubbo.registry.address = nacos://10.10.171.249:8848 spring.cloud.nacos.discovery.server-addr=10.10.171.249:8848 dubbo.registry.register=false #dubbo.protocol.id=dubbo 

遇坑总结

1. spring.application.name= 不写报错：提示使用spring.application.name的时候报错了，写上了但是并不能改变nacos上的服务名。

org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'targeterBeanPostProcessor' defined in class path resource [com/alibaba/cloud/dubbo/autoconfigure/DubboOpenFeignAutoConfiguration.class]: Unsatisfied dependency expressed through method 'targeterBeanPostProcessor' parameter 1; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'com.alibaba.cloud.dubbo.metadata.repository.DubboServiceMetadataRepository': Injection of autowired dependencies failed; nested exception is java.lang.IllegalArgumentException: Could not resolve placeholder 'spring.application.name' in value "${spring.application.name}" 

2. spring.cloud.nacos.discovery.server-addr= 不写报错,我的nacos服务器不在本地，日志却提示连本地连不上，肯定是因为我没写nacos地址

com.alibaba.nacos.api.exception.NacosException: failed to req API:/api//nacos/v1/ns/service/list after all servers([localhost:8848]) tried: java.net.ConnectException: Connection refused: connect 

3. dubbo.application.id=不写报错:

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'springCloudAlibabaDubboConsumerApplication': Injection of @Reference dependencies is failed; nested exception is java.lang.IllegalStateException: Invalid name="org.apache.dubbo.config.ApplicationConfig#0" contains illegal character, only digit, letter, '-', '_' or '.' is legal. 

4. 比前2个例子多出2个服务，是元数据，具体作用未知，怎么下掉未知，未来会慢慢研究。
   

本文地址：https://blog.csdn.net/lwb314/article/details/108239842