springcloud情操陶冶-初识springcloud

许久以前便听到了springcloud如雷贯耳的大名，可是未曾谋面，其主要应用于微服务的相关架构。笔者对微服务并非很了解，但其既然比较出众，遂也稍微接触研究下

springcloud特性

springcloud做为spring团队的微服务架构，其有以下的特性(摘自官方文档)

• Distributed/versioned configuration(分布式/版本化配置)
• Service registration and discovery(服务注册与发现)
• Routing(路由)
• Service-to-service calls(服务间远程调用)
• Load balancing(负载均衡)
• Circuit Breakers(熔断器)
• Distributed messaging(分布式消息)

应该就是微服务的相关特性，笔者不对上述的概念进行阐述，读者可相应的查阅相关文档

springcloud config

springcloud板块下有不少的分支，根本看不过来，就挑笔者比较感兴趣的配置管理springcloud config做为分析的入口把。具体的使用以及概念本文就不展开了，在官方文档上都有，笔者喜欢从源码角度看下springcloud是如何整合springboot进行扩展的

MAVEN依赖

根据官方的例子，笔者最后仍是经过IDEA开发工具引入Spring Initializr构建工具来生成springcloud config的相关maven配置

<?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>2.1.1.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.example</groupId>
    <artifactId>cloud-demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>cloud-demo</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
        <spring-cloud.version>Greenwich.RC2</spring-cloud.version>
    </properties>

    <dependencies>
        <!--server也依赖client板块-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-config-server</artifactId>
        </dependency>
        <!--client板块引入，若是只须要客户端，则只引入此依赖便可-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-config</artifactId>
        </dependency>

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </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>

其依托于spring-boot-starter-parent板块进行构建，上述的简单配置其实引入了spring/springboot/springcloud三大板块及其相应依赖，具体就不展现了，读者可自行查看

config启动方式

能够分几种状况来启动相应的服务

---

linux方式启动

$ cd cloud-demo
$ ./mvnw spring-boot:run

---

window方式启动

> cd cloud-demo
> call mvnw.cmd spring-boot:run

---

IDEA方式启动，写一个启动类携带上@EnableConfigServer注解便可，例如

package com.example.cloud.app;

import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.builder.SpringApplicationBuilder;
import org.springframework.cloud.config.server.EnableConfigServer;

/**
 * @author nanco
 * -------------
 * cloud-demo
 * -------------
 * @create 
 * @descrption
 **/
@SpringBootApplication
@EnableConfigServer
public class CloudConfigApp {

    public static void main(String[] args) {
        SpringApplicationBuilder appBuilder = new SpringApplicationBuilder(CloudConfigApp.class);
        // load certain properties
        appBuilder.properties("spring.config.name=configapp").run(args);
    }
}

小结

笔者以此篇做为springcloud的开篇，而且也把springcloud config板块做为后续的了解突破口。但在深刻应用服务以前，笔者以为仍是颇有必要对cloud的context模块做下详细的分析，以方便后续的讲解。