SpringCloud:(一)服務註冊與發現

最近跟着方誌明老師學習SpringCloud，博客地址以下：

https://blog.csdn.net/forezp/article/details/81040925

本身也跟着擼了一遍，紙上得來終覺淺，絕知此事要躬行，如下是本身擼的時候的總結&注意事項：

（一）建立maven項目

打開idea

File—new—project—maven

建立maven項目

Pom文件導入相應服務的依賴

<?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>springcloud</groupId>
 <artifactId>clouddemo</artifactId>
 <version>1.0-SNAPSHOT</version>
 <packaging>pom</packaging>

 <name>clouddemo</name>
 <description>Demo project for Spring Boot</description>

 <parent>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-starter-parent</artifactId>
 <version>2.1.1.RELEASE</version>
 <relativePath/>
 </parent>

 <modules>
 <module>eureka-server</module>
 <module>service-hi</module>
 </modules>

 <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.RELEASE</spring-cloud.version>
 </properties>

 <dependencies>
 <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>
注：

version版本升級到了2.1.1，否則會報

java.lang.AbstractMethodError: null at org.springframework.core.OrderComparator.findOrder等錯誤

<version>2.1.1.RELEASE</version>
（二）建立2個model工程做爲服務註冊中心：Eureka server & Eureka client

2.1Eureka server

2.1.1

父項目—new—module—spring initializr—cloud discovery—eureka server

 

繼承父pom文件，引入spring—cloud—starter—Netflix—eureka—server的依賴

<?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>springcloud</groupId>
 <artifactId>clouddemo</artifactId>
 <version>1.0-SNAPSHOT</version>
 </parent>

 <groupId>com.springcloud</groupId>
 <artifactId>eureka-server</artifactId>
 <version>0.0.1-SNAPSHOT</version>
 <packaging>jar</packaging>

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

 <properties>
 <java.version>1.8</java.version>
 <spring-cloud.version>Greenwich.SR1</spring-cloud.version>
 </properties>

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

 </dependencies>

</project>
2.1.2
啓動一個服務註冊中心，須要一個註解@EnableEurekaServer，這個註解須要在springboot工程的啓動application類上加：

@SpringBootApplication
@EnableEurekaServer
public class EurekaServerApplication {

 public static void main(String[] args) {

 SpringApplication.run(EurekaServerApplication.class, args);
 }

}

2.1.3配置文件appication.yml，指定server：

server:
 port: 8761

eureka:
 instance:
 hostname: localhost
 client:
 #經過eureka.client.registerWithEureka：false和fetchRegistry
 #false來代表本身是一個eureka server
 registerWithEureka: false
 fetchRegistry: false
 serviceUrl:
 defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/

spring:
 application:
 name: eurka-server
完成之後，啓動服務，打開啓動工程,打開瀏覽器訪問：

http://localhost:8761頁面，顯示沒有服務--沒有註冊服務固然不可能有服務被發現了。。。。

 

2.2 Eureka client--server-hi

步驟同2.1，建立module項目（服務提供者）

pom文件

<?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>springcloud</groupId>
 <artifactId>clouddemo</artifactId>
 <version>1.0-SNAPSHOT</version>
 </parent>

 <groupId>com.eureka.client</groupId>
 <artifactId>service-hi</artifactId>
 <version>0.0.1-SNAPSHOT</version>
 <packaging>jar</packaging>

 <name>service-hi</name>
 <description>Demo project for Spring Boot</description>

 <properties>
 <java.version>1.8</java.version>
 <spring-cloud.version>Greenwich.SR1</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-web</artifactId>
 </dependency>
 </dependencies>


 <build>
 <plugins>
 <plugin>
 <groupId>org.springframework.boot</groupId>
 <artifactId>spring-boot-maven-plugin</artifactId>
 </plugin>
 </plugins>
 </build>

</project>
2.2.1啓動類添加註解，註解@EnableEurekaClient 代表本身是一個eurekaclient

@SpringBootApplication
@EnableEurekaClient
@RestController
public class ServiceHiApplication {

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

@Value("${server.port}")
String port;

@RequestMapping("/hi")
public String home(@RequestParam(value = "name", defaultValue = "clouddemo") String name) {
return "hi " + name + " ,i am from port:" + port;
}

}

2.2.2在配置文件中註明本身的服務註冊中心的地址

server:
 port: 8762

spring:
 application:
 name: service-hi

eureka:
 client:
 serviceUrl:
 defaultZone: http://localhost:8761/eureka/

3.1啓動eureka-server服務，打開 http://localhost:8761

3.2啓動service-hi服務，訪問service-hi頁面，http://localhost:8762/hi?name=clouddemo

 

3.3刷新eureka-server訪問的頁面
服務已經註冊在服務中了，服務名爲SERVICE-HI ,端口爲7862