使用IDEA一步步搭建SpringCloud项目

SpringCloud简单搭建

前面已经介绍过SpringBoot与Mybatis,Redis,ActiveMQ的整合。接下来要做的是SpringCloud的项目的搭建。
在微服务的架构体系中,SpringBoot只能用于应用开发,而想要实现完整的微服务架构,还需要实现架构中的服务注册与发现,API网关和负载均衡等功能。接下来通过SpringCloud来实现架构中的这些功能。
在创建项目之前,需要了解的是SpringCloud与SpringBoot的版本号区别是:
SpringBoot是通过数字来区分版本号的,而SpringCloud是根据英文字母的顺序,采用伦敦的"地名+版本号"的方式来命名的。例如:Angel SR6,Brixton SR7,Camden SR7,Dalston SR3.其中Angel, Brixton,Camden,Dalston是地名,SR是Service Releases的编写。,后面的数字是版本号。
要求:
jdk:1.8
开发工具:IDEA
注:需要了解springcloud

1.创建基于web的Maven项目(springcloud)

2.创建服务注册中心。在springcloud项目中创建SpringBoot项目(springboot):

使用IDEA一步步搭建SpringCloud项目
选中项目右击–>New–>Module
勾选Cloud Discovery–>Eureka server。以方便导包。

3.编写springboot项目

3.1查看pom.xml文件
<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.1.2.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>springboot</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>springboot</name>
<description>Demo project for Spring Boot</description>

<properties>
    <java.version>1.8</java.version>
    <spring-cloud.version>Greenwich.RC2</spring-cloud.version>
</properties>

<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-eureka-server</artifactId>
        <version>1.4.2.RELEASE</version>
    </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>
3.2修改application.yml文件

server:
port: 8761
eureka:
instance:
hostname: localhost
client:
registerWithEureka: false
fetchRegistry: false
serviceUrl:
defaultZone: http://eureka.instance.hostname:{eureka.instance.hostname}:{server.port}/eureka/

registerWithEureka 和 fetchRegistry 设置为false,表明自己属于服务中心主体
为什么要用yml文件?而不是xml或properties文件?
说明:xml或properties文件都是以标签来配置数据,这样就造成了资源的浪费,不利于我们开发大型项目,而yml(yaml)文件则取消了这样的配置,文件中都是以数据为中心,层级结构以空格作为层级分隔符。使数据得到突出,简化了开发,同时占用的资源也更少。

3.3编写启动类SpringbootApplication.java

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

@SpringBootApplication
@EnableEurekaServer
public class SpringbootApplication {
public static void main(String[] args) {
    SpringApplication.run(SpringbootApplication.class, args);
}
}

添加@EnableEurekaServer,该注解表明标注类是一个Eureka Server。

4.启动项目

在浏览器中输入http://localhost:8761/
使用IDEA一步步搭建SpringCloud项目
使用IDEA一步步搭建SpringCloud项目

5.创建生产者

创建方式与服务注册中心相同。

5.1查看pom.xml文件

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.1.2.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>springbootclient</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>springbootclient</name>
<description>Demo project for Spring Boot</description>

<properties>
    <java.version>1.8</java.version>
    <spring-cloud.version>Greenwich.RC2</spring-cloud.version>
</properties>

<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-eureka-server</artifactId>
        <version>1.4.4.RELEASE</version>
    </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>

<repositories>
    <repository>
        <id>spring-milestones</id>
        <name>Spring Milestones</name>
        <url>https://repo.spring.io/milestone</url>
    </repository>
</repositories>

5.2修改application.yml文件

eureka:
client:
serviceUrl:
defaultZone: http://localhost:8761/eureka/
server:
port: 8763
spring:
application:
name: service-hi
注:端口不能与上面的相同。这里的服务name:service-hi 可以根据自己情况定义。

5.3编写启动类

在application中加入注解@EnableEurekaClient,表明自己属于一个生产者。这里为了方便测试,直接使用@RestController获取返回值。
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

@SpringBootApplication
@EnableEurekaClient
@RestController
public class SpringbootclientApplication {
public static void main(String[] args) {
    SpringApplication.run(SpringbootclientApplication.class, args);
}
@Value("${server.port}")
String port;

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

5.4运行服务

在浏览器中输入http://localhost:8765/hi?name=fys,可以看到如下信息
使用IDEA一步步搭建SpringCloud项目
然后查看http://localhost:8761/
使用IDEA一步步搭建SpringCloud项目
上图说明我们的服务者注册成功!

6.创建消费者

6.1 创建消费者modul,流程如上述工程创建流程。

6.2查看pom.xml文件

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.1.2.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.example</groupId>
<artifactId>serviceribbon</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>serviceribbon</name>
<description>Demo project for Spring Boot</description>

<properties>
    <java.version>1.8</java.version>
    <spring-cloud.version>Greenwich.RC2</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-test</artifactId>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-eureka</artifactId>
        <version>1.4.4.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-ribbon</artifactId>
        <version>1.4.2.RELEASE</version>
    </dependency>
    <!--断路器-->
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-hystrix</artifactId>
        <version>1.4.4.RELEASE</version>
    </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>

6.3yml配置

eureka:
client:
serviceUrl:
defaultZone: http://localhost:8761/eureka/
server:
port: 8764
spring:
application:
name: service-ribbon
在工程的配置文件指定服务的注册中心地址为http://localhost:8761/eureka/ 。#### 6.4编写启动类
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 ServiceribbonApplication {

  public static void main(String[] args) {

    SpringApplication.run(ServiceribbonApplication.class, args);
  }
@Bean
@LoadBalanced
RestTemplate restTemplate()
{
    return new RestTemplate();
}
}

@EnableDiscoveryClient表明标注类是消费者,加入restTemplate以消费相关的服务

7.创建service和controller

7.1 service层

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;

@Service
public class HelloService {
@Autowired
RestTemplate restTemplate;
public String hiService(String name)
{
    return restTemplate.getForObject("http://SERVICE-HI/hi?name=" + name, String.class);
}
}
7.2 controller层

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

@RestController
public class HelloControler {
@Autowired
HelloService helloService;
@RequestMapping(value = "/hi")
public String hi(@RequestParam String name)
{
    return helloService.hiService(name);
}
}

这里利用字符串进行传输。当然restTemplate也是可以以对象进行传输的。

8.运行服务

在浏览器中输入http://localhost:8764/hi?name=admin

使用IDEA一步步搭建SpringCloud项目
输入http://localhost:8761/
使用IDEA一步步搭建SpringCloud项目
上面的图说明:我们的消费者注册成功!