Spring Cloud Alibaba + Dubbo + Nacos 整合例子

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，性能更高，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，取个工程名，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-starter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

<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>4.0.0modelVersion>
    <groupId>com.lwbgroupId>
    <artifactId>spring-cloud-alibaba-dubbo-providerartifactId>
    <version>0.0.1-SNAPSHOTversion>
    <name>spring-cloud-alibaba-dubbo-providername>
    <description>Demo project for Spring Bootdescription>

    <properties>
        <java.version>1.8java.version>
        <project.build.sourceEncoding>UTF-8project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8project.reporting.outputEncoding>
        <spring-boot.version>2.2.7.RELEASEspring-boot.version>
        <spring-cloud-alibaba.version>2.2.1.RELEASEspring-cloud-alibaba.version>
    properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-webartifactId>
        dependency>




        <dependency>
            <groupId>com.alibaba.cloudgroupId>
            <artifactId>spring-cloud-starter-alibaba-nacos-discoveryartifactId>
        dependency>
        <dependency>
            <groupId>com.alibaba.cloudgroupId>
            <artifactId>spring-cloud-starter-dubboartifactId>
        dependency>

        <dependency>
            <groupId>org.springframework.bootgroupId>
            <artifactId>spring-boot-starter-testartifactId>
            <scope>testscope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintagegroupId>
                    <artifactId>junit-vintage-engineartifactId>
                exclusion>
            exclusions>
        dependency>
    dependencies>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>com.alibaba.cloudgroupId>
                <artifactId>spring-cloud-alibaba-dependenciesartifactId>
                <version>${spring-cloud-alibaba.version}version>
                <type>pomtype>
                <scope>importscope>
            dependency>
            <dependency>
                <groupId>org.springframework.bootgroupId>
                <artifactId>spring-boot-dependenciesartifactId>
                <version>${spring-boot.version}version>
                <type>pomtype>
                <scope>importscope>
            dependency>
        dependencies>
    dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.pluginsgroupId>
                <artifactId>maven-compiler-pluginartifactId>
                <version>3.8.1version>
                <configuration>
                    <source>1.8source>
                    <target>1.8target>
                    <encoding>UTF-8encoding>
                configuration>
            plugin>
            <plugin>
                <groupId>org.springframework.bootgroupId>
                <artifactId>spring-boot-maven-pluginartifactId>
                <version>2.2.7.RELEASEversion>
                <configuration>
                    <mainClass>com.lwb.springcloudalibabadubboprovider.SpringCloudAlibabaDubboProviderApplication
                    mainClass>
                configuration>
                <executions>
                    <execution>
                        <id>repackageid>
                        <goals>
                            <goal>repackagegoal>
                        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。
   

最近我准备从0搭建一套基于Spring Cloud Alibaba的微服务框架