SpringCloud学习（一）：eureka注册中心和客户端
菜鸟学渣接触spring cloud 系列...
公司也上微服务了，再不学习下就凉了，所以来踩坑吧...
版本：
spring-boot: 2.0
spring-cloud: Finchley.SR1
SpringCloud注册中心可以用Eureka、consul、zookeeper之类的，这里用eureka。
能上图绝不BB：
一、Server端 [eureka-server]
引入依赖 spring-cloud-starter-netflix-eureka-server
1 <?xml version="1.0" encoding="UTF-8"?> 2 <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 3 xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> 4 <modelVersion>4.0.0</modelVersion> 5 6 <groupId>com.renzku</groupId> 7 <artifactId>eureka-server</artifactId> 8 <version>0.0.1-SNAPSHOT</version> 9 <packaging>jar</packaging> 10 11 <name>eureka-server</name> 12 <description>Demo project for Spring Boot</description> 13 14 <parent> 15 <groupId>org.springframework.boot</groupId> 16 <artifactId>spring-boot-starter-parent</artifactId> 17 <version>2.0.4.RELEASE</version> 18 <relativePath/> <!-- lookup parent from repository --> 19 </parent> 20 21 <properties> 22 <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> 23 <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding> 24 <java.version>1.8</java.version> 25 <spring-cloud.version>Finchley.SR1</spring-cloud.version> 26 </properties> 27 28 <dependencies> 29 <dependency> 30 <groupId>org.springframework.cloud</groupId> 31 <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId> 32 </dependency> 33 34 <dependency> 35 <groupId>org.springframework.boot</groupId> 36 <artifactId>spring-boot-starter-test</artifactId> 37 <scope>test</scope> 38 </dependency> 39 </dependencies> 40 41 <dependencyManagement> 42 <dependencies> 43 <dependency> 44 <groupId>org.springframework.cloud</groupId> 45 <artifactId>spring-cloud-dependencies</artifactId> 46 <version>${spring-cloud.version}</version> 47 <type>pom</type> 48 <scope>import</scope> 49 </dependency> 50 </dependencies> 51 </dependencyManagement> 52 53 <build> 54 <plugins> 55 <plugin> 56 <groupId>org.springframework.boot</groupId> 57 <artifactId>spring-boot-maven-plugin</artifactId> 58 </plugin> 59 </plugins> 60 </build> 61 62 63 </project>
配置文件 application.yml
server:
port: 8761
eureka:
instance:
hostname: localhost
lease-renewal-interval-in-seconds: 5 # 设置心跳的时间间隔（默认是30秒）
lease-expiration-duration-in-seconds: 20 # 如果现在超过了20秒的间隔（默认是90秒）则服务无效了
client:
registerWithEureka: false
fetchRegistry: false
service-url:
defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka
server:
waitTimeInMsWhenSyncEmpty: 0
eviction-interval-timer-in-ms: 30000 # eureka清理无效服务的间隔时间
enable-self-preservation: false # 设置为false表示关闭保护模式--某一个微服务不可用了，eureka清理掉
启动类 EurekaServerApplication.java
@SpringBootApplication @EnableEurekaServer public class EurekaServerApplication { public static void main(String[] args) { SpringApplication.run(EurekaServerApplication.class, args); } }
目录结构
一个简单的Server端完成，访问http://localhost:8761
二、Client端 [eureka-client-one]
引入依赖 spring-cloud-starter-netflix-eureka-client
<?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.renzku</groupId> <artifactId>eureka-client-one</artifactId> <version>0.0.1-SNAPSHOT</version> <packaging>jar</packaging> <name>eureka-client-one</name> <description>Demo project for Spring Boot</description> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.0.4.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>Finchley.SR1</spring-cloud.version> </properties> <dependencies> <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-web</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> </project>
配置文件 application.yml
server:
port: 8501
spring:
application:
name: eureka-client-one
eureka:
client:
serviceUrl:
defaultZone: http://localhost:8761/eureka/ # eureka server 设置的地址
启动类 EurekaClientOneApplication.java
@Configuration @ComponentScan @EnableAutoConfiguration @EnableEurekaClient public class EurekaClientOneApplication { public static void main(String[] args) { SpringApplication.run(EurekaClientOneApplication.class, args); } }
Rest服务 HelloWorld.java
@RestController public class HelloWorld { @RequestMapping("/") public String home(){ return "hello world"; } }
目录结构
一个简单的Client端完成，访问http://localhost:8501
三、结果
查看注册中心，再次访问 http://localhost:8761，eureka-client-one 已经展示到已注册的实例列表中了：
其中[eureka-client-one]为serviceId，其他注册到eureka-server的实例可以通过serviceId相互调用，还自带负载均衡...
