SpringCloud Eureka初体验

本是古典何须时尚 2023-02-23 08:52 3阅读 0赞

### 文章目录 ###

*   *  Eureka Server
     *   *  创建Eureka Server项目
         *  配置application.properties
         *  增加@EnableEurekaServer注解
         *  访问Eureka Server
     *  Eureka Client
     *   *  创建Eureka Client项目
         *  配置bootstrap.properties
         *  编写EurekaclientApplication.java
         *  访问Eureka Client
         *  在Eureka Server上查看Client的信息
     *  参考资料

Eureka是SpringCloud Netflix提供的服务发现组件，本文介绍Eureka Server及Client的搭建步骤。

## Eureka Server ##

### 创建Eureka Server项目 ###

为了方便起见，我们从[Spring Initializr][]创建一个Eureka Server :  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTIxMjQzMDQ_size_16_color_FFFFFF_t_70]  
将得到的压缩包解压后导入到idea中。

### 配置application.properties ###

在application.properties中加入以下配置：

server.port=8761
    
    eureka.client.register-with-eureka=false
    eureka.client.fetch-registry=false
    
    logging.level.com.netflix.eureka=OFF
    logging.level.com.netflix.discovery=OFF

### 增加@EnableEurekaServer注解 ###

给程序入口类中加上@EnableEurekaServer，标记这是一个Euraka Server应用，如下：

package com.example.eurekaserver;
    
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
    
    @EnableEurekaServer
    @SpringBootApplication
    public class EurekaserverApplication { 
    	public static void main(String[] args) { 
    		SpringApplication.run(EurekaserverApplication.class, args);
    	}
    }

完成以上步骤，不出意外的化就可以把程序跑起来了

### 访问Eureka Server ###

打开浏览器，输入地址`http://localhost:8761`,出现以下界面则表示Eureka Server创建成功：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTIxMjQzMDQ_size_16_color_FFFFFF_t_70 1]

## Eureka Client ##

### 创建Eureka Client项目 ###

同样，我们从[Spring Initializr][]创建一个Eureka Client :  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTIxMjQzMDQ_size_16_color_FFFFFF_t_70 2]

### 配置bootstrap.properties ###

创建bootstrap.properties配置文件，在文件中加入：

spring.application.name=a-bootiful-client

### 编写EurekaclientApplication.java ###

将Spring initializr默认生成的`EurekaclientApplication.java`替换成以下内容：

package com.example.eurekaclient;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.boot.SpringApplication;
    import org.springframework.boot.autoconfigure.SpringBootApplication;
    import org.springframework.cloud.client.ServiceInstance;
    import org.springframework.cloud.client.discovery.DiscoveryClient;
    import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
    import org.springframework.web.bind.annotation.PathVariable;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    import java.util.List;
    
    @EnableDiscoveryClient
    @SpringBootApplication
    public class EurekaclientApplication { 
    
    	public static void main(String[] args) { 
    		SpringApplication.run(EurekaclientApplication.class, args);
    	}
    }
    
    @RestController
    class ServiceInstanceRestController { 
    
    	@Autowired
    	private DiscoveryClient discoveryClient;
    
    	@RequestMapping("/service-instances/{applicationName}")
    	public List<ServiceInstance> serviceInstancesByApplicationName(
    			@PathVariable String applicationName) { 
    		return this.discoveryClient.getInstances(applicationName);
    	}
    }

完成上述步骤便可以运行该应用

### 访问Eureka Client ###

打开浏览器，输入地址`http://localhost:8080/service-instances/a-bootiful-client`,可以看到一下界面：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTIxMjQzMDQ_size_16_color_FFFFFF_t_70 3]

### 在Eureka Server上查看Client的信息 ###

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTIxMjQzMDQ_size_16_color_FFFFFF_t_70 4]

## 参考资料 ##

https://spring.io/guides/gs/service-registration-and-discovery/

[Spring Initializr]: https://start.spring.io/
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