Spring Cloud （一）Eureka（服务注册与消费详解）
Spring Cloud Eureka（服务注册与消费详解）
1.Spring Cloud Eureka 服务注册中心 Eureka原理 参考原文
2.项目工具及环境
- JDK1.8
- Spring boot 2.0
- Intellij Idea
- maven 3以上
maven下载资源包的时候会遇到无法下载的问题；更改maven镜像为国外的地址
ui
central
Human Readable Name for this Mirror.
http://uk.maven.org/maven2/
sprintio
central
Human Readable Name for this Mirror.
https://repo.spring.io/libs-snapshot/
3.开始创建项目开始搭建
1.先打建一个最基础的maven项目，然后就自己next，再依次填写即可
2.删除最该maven项目下的src文件夹，新建moudel
新建spring boot项目
先不选择依赖
然后搭建项目基本目录
4.进行配置
1.. 配置项目的公共pom.xml
<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>4.0.0modelVersion>
<groupId>cn.qxgroupId>
<artifactId>eurekaartifactId>
<packaging>pompackaging>
<version>1.0-SNAPSHOTversion>
<modules>
<module>demo-server1module>
<module>demo-clent1module>
modules>
<parent>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-parentartifactId>
<version>2.0.0.RELEASEversion>
<relativePath/>
parent>
<properties>
<project.build.sourceEncoding>UTF-8project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8project.reporting.outputEncoding>
<java.version>1.8java.version>
<spring-cloud.version>Finchley.M8spring-cloud.version>
properties>
<dependencies>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-cacheartifactId>
dependency>
<dependency>
<groupId>org.springframework.sessiongroupId>
<artifactId>spring-session-coreartifactId>
dependency>
<dependency>
<groupId>mysqlgroupId>
<artifactId>mysql-connector-javaartifactId>
<scope>runtimescope>
dependency>
<dependency>
<groupId>org.projectlombokgroupId>
<artifactId>lombokartifactId>
<optional>trueoptional>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-testartifactId>
<scope>testscope>
dependency>
dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloudgroupId>
<artifactId>spring-cloud-dependenciesartifactId>
<version>${spring-cloud.version}version>
<type>pomtype>
<scope>importscope>
dependency>
dependencies>
dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-maven-pluginartifactId>
plugin>
plugins>
build>
<repositories>
<repository>
<id>spring-milestonesid>
<name>Spring Milestonesname>
<url>https://repo.spring.io/milestoneurl>
<snapshots>
<enabled>falseenabled>
snapshots>
repository>
repositories>
project>2.. eureka-server的pom.xml文件的配置
<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">
<parent>
<artifactId>eurekaartifactId>
<groupId>cn.qxgroupId>
<version>1.0-SNAPSHOTversion>
parent>
<modelVersion>4.0.0modelVersion>
<artifactId>demo-sever1artifactId>
<dependencies>
<dependency>
<groupId>org.springframework.cloudgroupId>
<artifactId>spring-cloud-starter-netflix-eureka-serverartifactId>
dependency>
dependencies>
project>3.. eureka-server的application.yml
server:
port: 8001
spring:
application:
name: demo-server1
eureka:
instance:
hostname: localhost
client:
register-with-eureka: false
fetch-registry: false
service-url:
#defaultZone: http://peer2:8002/eureka,http://peer3:8003/eureka
defaultZone: http://localhost:8001/eureka/4.. eureka-server的启动注解
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
@SpringBootApplication
@EnableEurekaServer
public class DemoServer1Application {
public static void main(String[] args) {
SpringApplication.run(DemoServer1Application.class, args);
}
}配置好后启动即可。
5.eureka-client客户端，可以业务工程可以理解为服务提供者
- eureka-client的pom.xml
<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">
<parent>
<artifactId>eurekaartifactId>
<groupId>cn.qxgroupId>
<version>1.0-SNAPSHOTversion>
parent>
<modelVersion>4.0.0modelVersion>
<artifactId>demo-client1artifactId>
<dependencies>
<dependency>
<groupId>org.springframework.cloudgroupId>
<artifactId>spring-cloud-starter-netflix-eureka-clientartifactId>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-webartifactId>
dependency>
dependencies>
project>- eureka-client的application.yml
spring:
application:
name: demo-clent
server:
port: 9001
eureka:
client:
service-url:
defaultZone: http://localhost:8001/eureka/
- eureka-client启动注解
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
@SpringBootApplication
@EnableEurekaClient
public class DemoClent1Application {
public static void main(String[] args) {
SpringApplication.run(DemoClent1Application.class, args);
}
}- eureka-client创建一个HelloController提供外界访问
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class HelloController {
@RequestMapping("/info")
public String Hello(){
return "hello xxx，this is demo-client1 messge";
}
/*
服务提供者
*/
@RequestMapping("/producerHello")
public String Hello(@RequestParam("name") String name){
return "hello " + name + "，this is demo-client1 messge";
}
}- 可以再创建一个服务提供者，仅仅application.yml端口不一样，其它的无区别
spring:
application:
name: demo-clent
server:
port: 9002
eureka:
client:
service-url:
defaultZone: http://localhost:8001/eureka/
- eureka-consumer配置及代码
ss- eureka-consumer的pom.xml
<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">
<parent>
<artifactId>eurekaartifactId>
<groupId>cn.qxgroupId>
<version>1.0-SNAPSHOTversion>
parent>
<modelVersion>4.0.0modelVersion>
<artifactId>demo-consumer1artifactId>
<dependencies>
<dependency>
<groupId>org.springframework.cloudgroupId>
<artifactId>spring-cloud-starter-netflix-eureka-clientartifactId>
dependency>
<dependency>
<groupId>org.springframework.cloudgroupId>
<artifactId>spring-cloud-starter-openfeignartifactId>
dependency>
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-webartifactId>
dependency>
dependencies>
project>- eureka-consumer的application.yml
spring:
application:
name: demo-consumer1
server:
port: 7001
eureka:
client:
service-url:
defaultZone: http://localhost:8001/eureka/
- eureka-consumer的代码
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.openfeign.EnableFeignClients;
@EnableEurekaClient
@EnableFeignClients
@SpringBootApplication
public class DemoConsumer1Application {
public static void main(String[] args) {
SpringApplication.run(DemoConsumer1Application.class, args);
}
}
//@EnableDiscoveryClient :启用服务注册与发现
//@EnableFeignClients：启用feign进行远程调用eureka-consumer的feign调用实现
//name:远程服务名，即spring.application.name配置的名称
@Service
@FeignClient(name= "demo-clent")
public interface HelloRemote {
//需要匹配服务提供者接口名称
@RequestMapping(value = "/producerHello")
public String sayHello(@RequestParam(value="name") String name);
}eureka-consumer的web层调用实现
@RestController
public class ConsumerController {
@Autowired
HelloRemote helloRemote;
/*
消费者的接口，去调用服务提供者
问题：只能使用@RequestMapping("/consumerHello/{name}") @PathVariable("name")方法 不知道有没有其它方式代替？
*/
@RequestMapping("/consumerHello/{name}")
public String index(@PathVariable("name") String name){
return helloRemote.sayHello(name);
}
//有问题的
// @RequestMapping("/consumerHello2")
// public String index2(@RequestParam("name") String name){
// return helloRemote.sayHello(name);
// }
@RequestMapping("/info")
public String info(){
return " Hi,I am a consumer!";
}
}测试
分别启动DemoServer1,DemoClient1,DemoClient2,DemoConsumer工程
- 在浏览器中输入http://localhost:8001/ 会出现2个 DEMO-CLENT项目，一个DEMO-CONSUMER1
- 在浏览器中输入http://localhost:9001/info会出现 hello xxx，this is demo-client1 messge
- 在浏览器中输入http://localhost:9002/info会出现 hello xxx，this is demo-client2 messge
- 在浏览器中输入http://localhost:7001/consumerHello/name会出现 hello name，this is demo-client1 messge ，多次访问会出现hello name，this is demo-client2 messge；因为服务中心自动提供了服务均衡负载的功能
Eureka-Server集群的配置参考Eureka-Server集群
问题集合
- 问题： eureka-client注册不上
- 解决： 添加 spring-boot-starter-web依赖包
<dependency>
<groupId>org.springframework.bootgroupId>
<artifactId>spring-boot-starter-webartifactId>
dependency>- 问题：spring-cloud-starter-feign依赖包引入不进来
- 解决：feign的依赖包名字有点改变，需要引入spring-cloud-starter-openfeign
ss