前言

之前用過SpringBoot之後，樓主有種虎穴一震的感覺，不禁感嘆天下居然有這麼好用的框架，雖然最近公司依舊比較忙，好在自己任務完成了，就忙裡偷閒開始學習一下SpringCloud（SpringCloud是建立在SpringBoot的基礎之上的），趁此機會和大家分享一下，希望大家能夠給予寶貴的建議。

正文

SpringCloud簡介

“微服務架構”在這幾年非常的火熱，以至於關於微服務架構相關的開源產品被反覆的提及（比如：netflix、dubbo），Spring Cloud也因Spring社群的強大知名度和影響力也被廣大架構師與開發者備受關注。
那麼什麼是“微服務架構”呢？簡單的說，微服務架構就是將一個完整的應用從資料儲存開始垂直拆分成多個不同的服務，每個服務都能獨立部署、獨立維護、獨立擴充套件，服務與服務間通過諸如RESTful API的方式互相呼叫。

微服務架構

服務治理

Spring Cloud Eureka

實戰

註冊中心

<name>spring-cloud-eureka</name>
	<description>Demo project for Spring Boot</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>1.5.9.RELEASE</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
		<java.version>1.8</java.version>
		<spring-cloud.version>Edgware.RELEASE</spring-cloud.version>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-eureka-server</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

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

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;

@EnableEurekaServer
@SpringBootApplication
public class SpringCloudEurekaApplication {
	public static void main(String[] args) {
		SpringApplication.run(SpringCloudEurekaApplication.class, args);
	}
}

spring.application.name=eureka-server
server.port=1001
eureka.instance.hostname=localhost
eureka.client.register-with-eureka=false
eureka.client.fetch-registry=false
eureka.client.serviceUrl.defaultZone=http://localhost:1001/eureka/

建立服務提供方

<name>spring-cloud-eureka-client</name>
	<description>Demo project for Spring Boot</description>

	<parent>
		<groupId>org.springframework.boot</groupId>
		<artifactId>spring-boot-starter-parent</artifactId>
		<version>1.5.9.RELEASE</version>
		<relativePath/> <!-- lookup parent from repository -->
	</parent>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
		<java.version>1.8</java.version>
		<spring-cloud.version>Edgware.RELEASE</spring-cloud.version>
	</properties>

	<dependencies>
		<dependency>
			<groupId>org.springframework.cloud</groupId>
			<artifactId>spring-cloud-starter-eureka</artifactId>
		</dependency>
		<dependency>
			<groupId>org.springframework.boot</groupId>
			<artifactId>spring-boot-starter-web</artifactId>
		</dependency>

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

package com.aikucun.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.cloud.client.discovery.DiscoveryClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;

/** 
* @FileName DisController.java
* @Description:TODO
* @author JackHisen(gu.weidong)
* @version V1.0
* @createtime 2018年1月16日 下午5:42:13 
* 修改歷史：
* 時間           作者          版本        描述
*====================================================  
*
*/
@RestController
public class DisController {
	@Autowired
    DiscoveryClient discoveryClient;
	@Value("${server.port}")
	String port;

    @GetMapping("/dc")
    public String dc() {
    	System.out.println("port:"+port);
        String services =port+ ",Services: " + discoveryClient.getServices();
        System.out.println(services);
        return services;
    }
}

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@EnableDiscoveryClient
@SpringBootApplication
public class SpringCloudEurekaClientApplication {
	public static void main(String[] args) {
		SpringApplication.run(SpringCloudEurekaClientApplication.class, args);
	}
}

spring.application.name=eureka-client
server.port=2001
eureka.client.serviceUrl.defaultZone=http://localhost:1001/eureka/

Services: [eureka-client]

其中，方括號中的eureka-client就是通過Spring Cloud定義的DiscoveryClient介面在eureka的實現中獲取到的所有服務清單。由於Spring Cloud在服務發現這一層做了非常好的抽象，所以，對於上面的程式，我們可以無縫的從eureka的服務治理體系切換到consul的服務治理體系中區。