Spring Cloud（一）：发现和注册服务（eureka）

最近的项目需要将原来的项目重构为Spring Boot项目，正好也能利用一些Spring Cloud的工具，就正好学习学习_(:з」∠*)_。
首先需要新建2个Spring Boot项目，一个作为服务注册中心，一个作为服务生产者/提供者。
如下

PS.我这里用的是Spring Boot 2.X版本

一.服务注册中心
新建Spring Boot项目SpringCloudServiceCenter
（1）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 http://maven.apache.org/xsd/maven-4.0.0.xsd">
   <modelVersion>4.0.0</modelVersion>

   <groupId>com.service.center</groupId>
   <artifactId>SpringCloundServiceCenter</artifactId>
   <version>0.0.1-SNAPSHOT</version>
   <packaging>jar</packaging>

   <name>SpringCloundServiceCenter</name>
   <description>com.service.center</description>

   <parent>
   	<groupId>org.springframework.boot</groupId>
   	<artifactId>spring-boot-starter-parent</artifactId>
   	<version>2.1.0.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>Greenwich.M1</spring-cloud.version>
   </properties>

   <dependencies>
   	<dependency>
   		<groupId>org.springframework.cloud</groupId>
   		<artifactId>spring-cloud-starter-netflix-eureka-server</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>
   		<snapshots>
   			<enabled>false</enabled>
   		</snapshots>
   	</repository>
   </repositories>
</project>

（2）application.properties配置

#服务端口
server.port=8761
#服务名称
eureka.instance.hostname=serviceCenter
#禁止本身注册
eureka.client.register-with-eureka=false
#禁止本身注册
eureka.client.fetch-registry=false
#服务中心地址
eureka.client.service-url.defaultZone=http://${eureka.instance.hostname}:${server.port}/eureka/

（3）SpringCloundServiceCenterApplication.java启动文件中添加@EnableEurekaServer

package com.service.center;

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

@SpringBootApplication
@EnableEurekaServer
public class SpringCloundServiceCenterApplication {

	public static void main(String[] args) {
		SpringApplication.run(SpringCloundServiceCenterApplication.class, args);
	}
}

来表明该服务为服务发现和注册中心
整体结构

（4）配置完成后启动，然后访问http://localhost:8761/ 就能进入eureka server监控界面，可以看到红框中的信息，现在还没有服务注册。

---

二.服务生产者
新建spring boot项目SpringCloudServiceI
（1）pom.xml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>

   <groupId>com.my.serviceI</groupId>
   <artifactId>SpringCloundServiceI</artifactId>
   <version>0.0.1-SNAPSHOT</version>
   <packaging>jar</packaging>

   <name>SpringCloundServiceI</name>
   <description>com.my.serviceI</description>

   <parent>
   	<groupId>org.springframework.boot</groupId>
   	<artifactId>spring-boot-starter-parent</artifactId>
   	<version>2.1.0.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>Greenwich.M1</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-netflix-eureka-client</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>
   		<snapshots>
   			<enabled>false</enabled>
   		</snapshots>
   	</repository>
   </repositories>
</project>

（2）application.properties配置

server.servlet.context-path=/myServiceI 
server.port=8762
spring.application.name=myServiceI  #服务名，在注册时所用
eureka.client.service-url.defautZone=http://serviceCenter:8761/eureka/

（3）在启动文件SpringCloundServiceIApplication.java中添加@EnableEurekaClient

package com.my.serviceI;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

@SpringBootApplication
@EnableEurekaClient
public class SpringCloundServiceIApplication {

	public static void main(String[] args) {
		SpringApplication.run(SpringCloundServiceIApplication.class, args);
	}
}

（4）新建一个controller文件，提供服务
例ServiceApiController.java

package com.my.serviceI.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;

@Controller
@RequestMapping(value="/Api")
public class ServiceApiController {
   @ResponseBody
   @RequestMapping(value="/getInfo")
   public String getInfo() {
   	return "123+";
   }
}

整体结构如下

可以启动测试下是否能访问接口服务，因为spring boot会内置一个tomcat容器，且在启动时会省略掉项目名，所以我这里在application.properties中配置server.servlet.context-path=/myServiceI 来把项目名加上了，所以现在接口的访问路径为http://localhost:8762/myServiceI/Api/getInfo

然后刷新下eureka server监控界面，就能看到刚才的服务了，能从信息中得知服务的名字和端口号，上面红条是另一个服务。