2018年10月31日,Spring Cloud 发布了 Spring Cloud Alibaba的首个版本,它是由一些阿里巴巴的开源组件和云产品组成的,主要功能有(官方介绍):
- 服务限流降级:默认支持 Servlet、Feign、RestTemplate、Dubbo 和 RocketMQ 限流降级功能的接入,可以在运行时通过控制台实时修改限流降级规则,还支持查看限流降级 Metrics 监控。
- 服务注册与发现:适配 Spring Cloud 服务注册与发现标准,默认集成了 Ribbon 的支持。
- 分布式配置管理:支持分布式系统中的外部化配置,配置更改时自动刷新。
- 消息驱动能力:基于 Spring Cloud Stream 为微服务应用构建消息驱动能力。
- 分布式事务:使用 @GlobalTransactional 注解, 高效并且对业务零侵入地解决分布式事务问题。
- 阿里云对象存储:阿里云提供的海量、安全、低成本、高可靠的云存储服务。支持在任何应用、任何时间、任何地点存储和访问任意类型的数据。
- 分布式任务调度:提供秒级、精准、高可靠、高可用的定时(基于 Cron 表达式)任务调度服务。同时提供分布式的任务执行模型,如网格任务。网格任务支持海量子任务均匀分配到所有 Worker(schedulerx-client)上执行。
- 阿里云短信服务:覆盖全球的短信服务,友好、高效、智能的互联化通讯能力,帮助企业迅速搭建客户触达通道。
本文分两部分来介绍通过Nacos实现配置管理和动态服务发现。
一、配置管理
1.安装Naocs(Linux环境)
首先下载Nacos压缩包:https://github.com/alibaba/nacos/releases ,下载后使用tar命令解压,进入bin目录,运行下面命令启动:
sh startup.sh -m standalone
然后访问http:/x.x.x.x:8848/nacos/index.html(x.x.x.x为安装服务器),输入用户名密码(默认都是nacos),登录后看到:
至此Nacos安装成功。
2. 实现动态配置管理
首先在Nacos新增配置,点击+号:
填写Data Id、Group和内容,配置格式选择YAML。
其中Data Id的完整格式为:
${prefix}-${spring.profile.active}.${file-extension}
prefix 默认为 spring.application.name 的值,也可以通过配置项 spring.cloud.nacos.config.prefix来配置。
spring.profile.active 即为当前环境对应的 profile,注意:当 spring.profile.active 为空时,对应的连接符 - 也将不存在,dataId 的拼接格式变成 ${prefix}.${file-extension}
file-exetension 为配置内容的数据格式,可以通过配置项 spring.cloud.nacos.config.file-extension 来配置。目前只支持 properties 和 yaml 类型。
配置完成后使用IDEA新建空的maven项目,创建完后删除src目录,修改pom文件内容如下:
<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.1.3.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.xiaobai</groupId>
<artifactId>spring-cloud-alibaba-demo</artifactId>
<version>1.0-SNAPSHOT</version>
<packaging>pom</packaging>
<modules>
<module>config-client</module>
<module>service-discovery</module>
</modules>
</project>
新建config-client模块,选择Spring Initializr创建Spring Boot工程,依赖选择:
创建完成后修改pom文件parent节点并添加依赖:
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
<version>0.2.1.RELEASE</version>
</dependency>
完整pom文件如下:
<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>com.xiaobai</groupId>
<artifactId>spring-cloud-alibaba-demo</artifactId>
<version>1.0-SNAPSHOT</version>
</parent>
<groupId>com.xiaobai</groupId>
<artifactId>config-client</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>config-client</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
<spring-cloud.version>Greenwich.RELEASE</spring-cloud.version>
</properties>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
<version>0.2.1.RELEASE</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
修改配置文件名称为bootstrap.yml(或bootstrap.properties,需要注意要获取Nacos配置的属性必须使用bootstrap),修改内容为:
server:
port: 8880
spring:
application:
name: config-client
cloud:
nacos:
config:
server-addr: x.x.x.x:8848
group: xiaobai
file-extension: yml
其中spring.application.name以及file-extension需要和配置的Data Id中对应(config-client.yml),group需要和配置的Group对应(xiaobai),server-addr是Nacos的安装地址。
给启动类添加@RefreshScope注解实现配置自动更新:
package com.xiaobai.configclient;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.context.config.annotation.RefreshScope;
@SpringBootApplication
@RefreshScope
public class ConfigClientApplication {
public static void main(String[] args) {
SpringApplication.run(ConfigClientApplication.class, args);
}
}
在con.xiaobai.configclient.controller下编写ConfigController:
package com.xiaobai.configclient.controller;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class ConfigController {
@Value("${message}")
private String message;
@RequestMapping("/config")
public String config(){
return message;
}
}
使用@Value注解来获取配置文件中的message,启动工程,访问http://localhost:8880/config可以看到成功获取到message:
二、服务发现(使用FeignClient调用)
创建服务提供者
新建service-discovery模块(空的maven项目),创建完成后删除src目录修改pom文件内容如下:
<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<parent>
<artifactId>spring-cloud-alibaba-demo</artifactId>
<groupId>com.xiaobai</groupId>
<version>1.0-SNAPSHOT</version>
</parent>
<modelVersion>4.0.0</modelVersion>
<packaging>pom</packaging>
<artifactId>service-discovery</artifactId>
<modules>
<module>service-provider</module>
<module>service-consumer</module>
</modules>
</project>
在service-discovery模块再创建service-provider子模块,选择Spring Initializr创建Spring Boot工程,依赖选择:
创建完成后修改pom文件parent节点并添加Spring Cloud依赖:
<properties>
<spring-cloud.version>Greenwich.RELEASE</spring-cloud.version>
</properties>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
和nacaos-discovery依赖:
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
<version>0.2.1.RELEASE</version>
</dependency>
完整pom文件如下:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>com.xiaobai</groupId>
<artifactId>service-discovery</artifactId>
<version>1.0-SNAPSHOT</version>
</parent>
<groupId>com.xiaobai</groupId>
<artifactId>service-provider</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>service-provider</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
<spring-cloud.version>Greenwich.RELEASE</spring-cloud.version>
</properties>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
<version>0.2.1.RELEASE</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
修改application.yml(application.properties)配置文件:
server:
port: 8888
spring:
application:
name: service-provider
cloud:
nacos:
discovery:
server-addr: x.x.x.x:8848
server-addr是nacos注册中心的地址。
启动类添加@EnableDiscoveryClient注解:
package com.xiaobai.serviceprovider;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
@SpringBootApplication
@EnableDiscoveryClient
public class ServiceProviderApplication {
public static void main(String[] args) {
SpringApplication.run(ServiceProviderApplication.class, args);
}
}
在com.xiaobai.serviceprovider.service下新建SayHelloService接口:
package com.xiaobai.serviceprovider.service;
public interface SayHelloService {
public String sayHello(String name);
}
在com.xiaobai.serviceprovider.service.Impl下新建接口的实现类:
package com.xiaobai.serviceprovider.service.Impl;
import com.xiaobai.serviceprovider.service.SayHelloService;
import org.springframework.stereotype.Service;
@Service
public class SayHelloImpl implements SayHelloService {
public String sayHello(String name){
return "Hello " + name + "!";
}
}
在com.xiaobai.serviceprovider.controller下新建SayHelloController:
package com.xiaobai.serviceprovider.controller;
import com.xiaobai.serviceprovider.service.SayHelloService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class SayHelloController {
@Autowired
private SayHelloService sayHelloService;
@RequestMapping("/sayHello")
public String sayHello(@RequestParam("name")String name){
return sayHelloService.sayHello(name);
}
}
启动项目,查看nacos服务管理中已经注册成功:
创建服务消费者
在service-discovery模块再创建service-consumer子模块,选择Spring Initializr创建Spring Boot工程,依赖选择:
创建完成后修改pom文件parent节点并添加nacos-discovery依赖:
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
<version>0.2.1.RELEASE</version>
</dependency>
完整pom文件如下:
<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>com.xiaobai</groupId>
<artifactId>service-discovery</artifactId>
<version>1.0-SNAPSHOT</version>
</parent>
<groupId>com.xiaobai</groupId>
<artifactId>service-consumer</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>service-consumer</name>
<description>Demo project for Spring Boot</description>
<properties>
<java.version>1.8</java.version>
<spring-cloud.version>Greenwich.RELEASE</spring-cloud.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
<version>0.2.1.RELEASE</version>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
<repositories>
<repository>
<id>spring-milestones</id>
<name>Spring Milestones</name>
<url>https://repo.spring.io/milestone</url>
</repository>
</repositories>
</project>
修改application.yml(application.properties)配置文件:
server:
port: 80
spring:
application:
name: service-consumer
cloud:
nacos:
discovery:
server-addr: x.x.x.x:8848
启动类添加@EnableDiscoveryClient和@EnableFeignClients注解:
package com.xiaobai.serviceconsumer;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.openfeign.EnableFeignClients;
@SpringBootApplication
@EnableDiscoveryClient
@EnableFeignClients
public class ServiceConsumerApplication {
public static void main(String[] args) {
SpringApplication.run(ServiceConsumerApplication.class, args);
}
}
在com.xiaobai.serviceconsumer.service下新建接口SayHelloService:
package com.xiaobai.serviceconsumer.service;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
@FeignClient("service-provider")
public interface SayHelloService {
@RequestMapping("/sayHello")
public String sayHello(@RequestParam("name")String name);
}
在com.xiaobai.serviceconsumer.controller下新建TestController:
package com.xiaobai.serviceconsumer.controller;
import com.xiaobai.serviceconsumer.service.SayHelloService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class TestController {
@Autowired
private SayHelloService sayHelloService;
@RequestMapping("/test")
public String test(@RequestParam("name")String name){
return sayHelloService.sayHello(name);
}
}
启动项目,查看nacos服务管理,看到消费者已经注册成功:
访问http://localhost/test?name=xiaobai看到成功调用到service-provider的服务:
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