SpringCloud — (1) 服务治理Eureka

1.新建一个普通的mavent项目，作为注册中心

new maven-project→springcloud-2.0-eureka-server(jar)

pom.xml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">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.dengfeng</groupId>
  <artifactId>springcloud-2.0-eureka-server</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  
  <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.1.RELEASE</version>
    </parent>
    <!-- 管理依赖 -->
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Finchley.M7</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
    <dependencies>
        <!--SpringCloud eureka-server -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
        </dependency>
        
        <dependency>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-resources-plugin</artifactId>
            <version>3.0.1</version>
        </dependency>
        
    </dependencies>
    <!-- 注意： 这里必须要添加， 否者各种依赖有问题 -->
    <repositories>
        <repository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/libs-milestone</url>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
    </repositories>
</project>

这时控制台可能会报错，

Failure to transfer antlr:antlr:jar  XXXXXXXX

解决方案：

 　　a.删除本地仓库后缀.lastUpdated为扩展名的文件

 　　b. 然后在工程上点击右键，选择maven →Update Project

在srm/main/resource下新建application.yml

###eureka 服务端口号
server:
  port: 8100
###服务注册名称
eureka:
  instance:
    hostname: server1
###客户端调用地址
  client:
    serviceUrl:
      defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/
###因为该应用为注册中心，不会注册自己
    register-with-eureka: false
###因为自己为注册中心 ,不会去在该应用中的检测服务
    fetch-registry: false

创建注册中心启动类，AppEureka.java

package com.euraka;

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

@EnableEurekaServer  /*@EnableEurekaServer作用:开启eurekaServer*/
@SpringBootApplication
public class AppEureka {

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

}

启动后在输入地址 localhost:8100 看到注册中心管理页面

2.新建服务提供者工程

new maven-project→springcloud-2.0-member(jar)

pom.xml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">
  <modelVersion>4.0.0</modelVersion>
  <groupId>com.dengfeng</groupId>
  <artifactId>springcloud-2.0-member</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  
  
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.1.RELEASE</version>
    </parent>
    <!-- 管理依赖 -->
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Finchley.M7</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
    <dependencies>
        <!-- SpringBoot整合Web组件 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!-- SpringBoot整合eureka客户端 -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>
    </dependencies>
    <!-- 注意： 这里必须要添加， 否者各种依赖有问题 -->
    <repositories>
        <repository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/libs-milestone</url>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
    </repositories>

  
</project>

application.yml

###服务启动端口号
server:
  port: 8000
###服务名称(服务注册到eureka名称)  
spring:
    application:
        name: app-dengfeng360-member
###服务注册到eureka地址
eureka:
  client:
    service-url:
           defaultZone: http://localhost:8100/eureka

           
###因为该应用为注册中心，不会注册自己
    register-with-eureka: true
###是否需要从eureka上获取注册信息,不需要去注册中心上检索服务
    fetch-registry: true

创建启动类和表现层 (AppMember,MemberController)

 

AppMember

package com.dengfeng.api.controller;

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

@SpringBootApplication
@EnableEurekaClient
public class AppMember {

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

}

MemberController

package com.dengfeng.api.controller;

import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class MemberController {

    @RequestMapping("/getMember")
    public String getMember() {
        return "this is getMember";
    }
}

启动提供者，可以在注册中心管理界面看到提供者信息

 3.创建消费者工程

new maven-project→springcloud-2.0-order(jar)

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>4.0.0</modelVersion>
  <groupId>com.dengfeng</groupId>
  <artifactId>springcloud-2.0-order</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  
  <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.1.RELEASE</version>
    </parent>
    <!-- 管理依赖 -->
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Finchley.M7</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>
    <dependencies>
        <!-- SpringBoot整合Web组件 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <!-- SpringBoot整合eureka客户端 -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
        </dependency>

    </dependencies>
    <!-- 注意： 这里必须要添加， 否者各种依赖有问题 -->
    <repositories>
        <repository>
            <id>spring-milestones</id>
            <name>Spring Milestones</name>
            <url>https://repo.spring.io/libs-milestone</url>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
    </repositories>
  
</project>

application.yml

###服务启动端口号
server:
  port: 8001
###服务名称(服务注册到eureka名称)  
spring:
    application:
        name: app-dengfeng360-order
###服务注册到eureka地址
eureka:
  client:
    service-url:
           defaultZone: http://localhost:8100/eureka

           
###因为该应用为注册中心，不会注册自己
    register-with-eureka: true
###是否需要从eureka上获取注册信息,不需要去注册中心上检索服务
    fetch-registry: true

创建消费者启动类和表现层类

AppOrder

package com.dengfeng.api.controller;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;

@SpringBootApplication
@EnableEurekaClient
public class AppOrder {

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

    //@LoadBalanced就能让这个RestTemplate在请求时拥有客户端负载均衡的能力
    @Bean
    @LoadBalanced
    RestTemplate restTemplate() {
        return new RestTemplate();
    }

}

 OrderController

package com.dengfeng.api.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

@RestController
public class OrderController {
    @Autowired
    private RestTemplate restTemplate;

    @RequestMapping("/getorder")
    public String getOrder() {
        // order 使用rpc 远程调用技术 调用 会员服务
        String memberUrl = "http://app-dengfeng360-member/getMember";
        String result = restTemplate.getForObject(memberUrl, String.class);
        System.out.println("订单服务调用会员服务,result=" + result);
        return result;
    }

}

启动消费者，刷新管理中心管理页面，有提供者和消费者信息

请求消费者getOrder方法

http://localhost:8001/getorder

---

附：注册中心管理页面status读取的是主机名而不是Ip，则需要在提供者和消费者配置文件yml加如下配置

  # 自定义实例编号
  instance:
    instance-id: ${spring.application.name}:${server.port}
    # 配置使用主机名注册服务
    hostname: node1
    # 优先使用IP地址方式进行注册服务
    prefer-ip-address: true
    ip-address: 127.0.0.1