SpringCloud简单实例
SpringCloud简单实例
SpringCloud是基于SpringBoot,需要先了解SpringBoot的相关知识。
这里只是一个非常简单的包含注册表、服务提供者、服务消费者三者的例子。
源码见:
https://github.com/mengyuxiaofeng/SpringCloud
注册表如下
启动类
package demo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
@SpringBootApplication
@EnableEurekaServer //声明这是一个Eureka服务器
public class EurekaServerApplication {
public static void main(String[] args)
{
SpringApplication.run(EurekaServerApplication.class, args);//后面是直接设置端口号
}
}
它的application.yml配置文件如下:(在resource文件下)
server:
port: 8761 #声明端口号
eureka:
client:
register-with-eureka: false #默认是true,将自己注册到eureka上
fetch-registry: false #是否从eureka上获取信息,由于本案例是单机,无需从别的eureka上获取注册信息
service-url:
defaultZone: http://localhost:8761/eureka #设置与eureka交互的地址,查询服务和注册服务都需要依赖这个地址,默认是:http://localhost:8761/eureka
它的pom.xml如下:
<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.huoli.SpringCloudDemo</groupId>
<artifactId>demo</artifactId>
<version>0.0.1-SNAPSHOT</version>
<!-- Spring Boot的核心 -->
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.6.RELEASE</version>
</parent>
<!-- springcloud版本声明 -->
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Dalston.SR3</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<dependencies>
<!-- 引入spring boot依赖 -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-jetty</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<!-- 引入eureka依赖 -->
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-eureka</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-eureka-server</artifactId>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<configuration>
<source>1.8</source>
<target>1.8</target>
</configuration>
</plugin>
</plugins>
</build>
</project>
启动刚开始的类EurekaServerApplication,在浏览器中有如下显示(刚开始是没有服务提供者的,这里是当服务提供者已经启动了才出现的)
服务提供者如下:
启动类
package demo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
@SpringBootApplication
@EnableDiscoveryClient //也可以用EnableDiscoveryClient代替,前者兼容性更大,后者仅能兼容Eureka
public class ServerProvider {
public static void main(String[] args) {
SpringApplication.run(ServerProvider.class, args);
}
}
controller类(注意和启动类的位置)
package demo;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class HelloController {
@RequestMapping("hello")
public String index() {
System.out.println("index is called");
return "Hello World";
}
}
application.yml文件
server:
port: 8000
spring:
application:
name: provider #注册到Eureka Server上的应用名称
eureka:
client:
service-url:
defaultZone: http://localhost:8761/eureka #注册的位置
instance:
prefer-ip-address: true #将自己的ip注册到EuekaServer上
pom.xml文件和注册表的一样
启动后,注册表的页面会有如下变化
服务消费者(忽略掉User类)
启动类
package demo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;
@SpringBootApplication
public class ServerConsumer {
@Bean
public RestTemplate restTemplate() {
return new RestTemplate();
}
public static void main(String[] args) {
SpringApplication.run(ServerConsumer.class, args);
}
}
controller类(这也是我们需要在浏览器访问的)
package demo;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
import demo.User;
@RestController
public class UserController {
@Autowired
private RestTemplate restTemplate;
@GetMapping("/hello")
public String getUser() {
return this.restTemplate.getForObject("http://localhost:8000/hello", String.class);
}
}
pom.xml还是和注册表的一样(但是都要写)
启动服务消费者,在浏览器中查看如下: