Spring Cloud源码分析之Eureka篇第一章:准备工作

大家好,从本章开始我们一起进入SpringCloud的源码世界,通过源码分析再结合实战,一起加深对SpringCloud体系的认识;

原文链接:https://blog.csdn.net/boling_cavalry/article/details/81809929

全文概览

本章是为后续的深度学习做准备工作,主要包含以下两部分:
1. 开发三个简单应用,包括:注册中心、服务提供方、服务消费方,后续研究和实战都在这三个应用基础上进行;
2. 下载后续分析研究中用到的源码,包括SpringCloud和Netflix的,版本和三个简单应用的一致;

版本列表

  1. JDK:1.8;
  2. spring boot:1.5.9.RELEASE;
  3. spring cloud:Edgware.RELEASE;

应用简介

用列表简介本章要开发的三个应用:

应用名称 作用 占用端口
springclouddeepeureka 注册中心 8081
springclouddeepprovider 服务提供方 8082
springclouddeepconsumer 服务消费方 8083

实战源码下载

稍后会详细介绍这三个应用的开发和测试步骤,您也可以在github下载这三个应用的源码,地址和链接信息如下表所示:

名称 链接 备注
项目主页 https://github.com/zq2599/blog_demos 该项目在GitHub上的主页
git仓库地址(https) https://github.com/zq2599/blog_demos.git 该项目源码的仓库地址,https协议
git仓库地址(ssh) [email protected]:zq2599/blog_demos.git 该项目源码的仓库地址,ssh协议

这个git项目中有多个文件夹,本章源码分别在springclouddeepeureka、springclouddeepprovider、springclouddeepconsumer这三个文件夹下,如下图红框所示:
这里写图片描述

接下来准备demo工程吧,先从Eureka开始:

Eureka应用

  1. 基于maven创建一个spring boot的web应用springclouddeepeureka,pom.xml内容如下:
<?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.bolingcavalry</groupId>
    <artifactId>springclouddeepeureka</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>springclouddeepeureka</name>
    <description>Demo project for Eureka server</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.9.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>
    </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>

    <!--spring cloud依赖管理-->
    <!-- 引入spring cloud的依赖 -->
    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Edgware.RELEASE</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>


2. resources目录下创建配置文件application.yml,内容如下:

server:
  port: 8081
eureka:
  client:
    registerWithEureka: false
    fetchRegistry: false
    serviceUrl:
      defaultZone: http://localhost:8081/eureka/


3. 启动类SpringclouddeepeurekaApplication.java中,添加注解@EnableEurekaServer

package com.bolingcavalry.springclouddeepeureka;

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

@SpringBootApplication
@EnableEurekaServer
public class SpringclouddeepeurekaApplication {

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


4. 启动应用,浏览器访问8081端口,可见Eureka页面如下图:
这里写图片描述

5. 至此,注册中心启动成功;

服务提供者

  1. 基于maven创建一个spring boot的web应用springclouddeepprovider,pom.xml内容如下:
<?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.bolingcavalry</groupId>
    <artifactId>springclouddeepprovider</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>springclouddeepprovider</name>
    <description>Demo project for Spring Cloud service provider</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.9.RELEASE</version>
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.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>Edgware.RELEASE</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>


2. resources目录下创建配置文件application.yml,内容如下:

server:
  port: 8082
spring:
  application:
    name: springcloud-deep-provider
eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8081/eureka/
  instance:
    prefer-ip-address: true


3. 启动类SpringclouddeepproviderApplication.java中,添加注解@EnableDiscoveryClient

package com.bolingcavalry.springclouddeepprovider;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;

@SpringBootApplication
@EnableDiscoveryClient
public class SpringclouddeepproviderApplication {

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


4. 创建一个Controller类,用于提供http服务:

package com.bolingcavalry.springclouddeepprovider.Controller;

import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

import java.text.SimpleDateFormat;
import java.util.Date;

/**
 * @Description : 提供普通的http服务
 * @Author : [email protected]
 * @Date : 2018-08-18 18:25
 */
@RestController
public class HelloService {

    @GetMapping("hello/{name}")
    public String hello(@PathVariable String name){
        return "Hello " + name + ", " + new SimpleDateFormat("yyyy-MM-dd hh:mm:ss").format(new Date());
    }
}


5. 启动应用,浏览器访问路径:http://localhost:8082/hello/123,可收到server端响应如下图:
这里写图片描述

6. 此时去刷新Eureka的页面,发现服务已经注册成功了,如下图:
这里写图片描述

至此,服务提供方应用开发完毕,最后一个是服务消费方springclouddeepconsumer;

服务消费方

  1. 基于maven创建一个spring boot的web应用springclouddeepconsumer,pom.xml内容如下:
<?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.bolingcavalry</groupId>
    <artifactId>springclouddeepconsumer</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>springclouddeepconsumer</name>
    <description>Demo project for Spring Cloud service consumer</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.9.RELEASE</version>
    </parent>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.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>

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

</project>


2. resources目录下创建配置文件application.yml,内容如下:

server:
  port: 8083
spring:
  application:
    name: springcloud-deep-consumer
eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8081/eureka/
  instance:
    prefer-ip-address: true


3. 启动类SpringclouddeepconsumerApplication.java中,添加注解@EnableDiscoveryClient

package com.bolingcavalry.springclouddeepconsumer;

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;

@SpringBootApplication
@EnableDiscoveryClient
public class SpringclouddeepconsumerApplication {

    @Bean
    @LoadBalanced
    public RestTemplate restTemplate() {
        return new RestTemplate();
    }

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


4. 创建一个Controller类,用于提供http服务:

package com.bolingcavalry.springclouddeepconsumer.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;

/**
 * @Description : 远程调用测试的
 * @Author : [email protected]
 * @Date : 2018-08-18 19:10
 */
@RestController
public class ConsumerServiceController {

    @Autowired
    private RestTemplate restTemplate;

    @Autowired
    private LoadBalancerClient loadBalancerClient;

    @GetMapping("serviceinfo")
    public String serviceinfo(){
        ServiceInstance serviceInstance = loadBalancerClient.choose("springcloud-deep-provider");
        return null==serviceInstance ? "service not found" : serviceInstance.toString();
    }

    @GetMapping("consume/{name}")
    public String consume(@PathVariable String name){
               return this.restTemplate.getForObject("http://springcloud-deep-provider/hello/" + name, String.class);
    }
}


5. 启动应用,浏览器访问路径:http://localhost:8083/consume/tom,可收到server端响应如下图:
这里写图片描述

6. 再试试获取服务信息的接口:http://localhost:8083/serviceinfo,可以看到服务信息:
这里写图片描述

7. 此时去刷新Eureka的页面,发现两个应用都已注册成功,如下图:
这里写图片描述

至此,服务消费方应用开发完毕,后续的章节中,我们的分析和实战都在这三个应用上进行;

Spring Cloud源码下载

简单说说如何在GitHub下载对应版本的Spring Cloud源码:
1. Spring Cloud的GitHub主页:https://github.com/spring-cloud
2. 假设我要下载的是子工程spring-cloud-commons的源码,版本号1.3.0-RELEASE,点击下图红框中的链接:
这里写图片描述

3. 在spring-cloud-commons工程主页中,点击下图红框中的”releases”链接:
这里写图片描述

4. 如下图,这里有多个release版本,挑选您所需的版本,点击红框中的链接即可下载源码:
这里写图片描述

Netflix源码下载

Netflix源码地址:https://github.com/Netflix,后面的章节中,我们会按需要来这里下载对应的release版本源码;

至此,咱们的准备工作已经完成,接下来一起去探索精彩的Spring Cloud世界吧;

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转载自blog.csdn.net/boling_cavalry/article/details/81809929