Ribbon:提供雲端負載均衡,有多種負載均衡政策可供選擇,可配合服務發現和斷路器使用。
上一篇簡單講解了eureka的使用,這一篇文章基于上一篇的基礎上,講一下springcloud的另一個重要的元件ribbon。
這篇文章需要建立三個工程,service(8762),service(8763),service-ribbon(8764),三個服務分别向eureka-server注冊中心注冊,本文的服務使用的注冊中心都是本人建立的測試eureka--
http://eureka.dalaoyang.cn。
首先建立一個service(8762),括号内的8762是項目的端口号,加入eureka依賴,pom檔案如下:
<?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.dalaoyang</groupId>
<artifactId>springcloud_service</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>springcloud_service</name>
<description>springcloud_service</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>
<spring-cloud.version>Edgware.SR1</spring-cloud.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-eureka</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>${spring-cloud.version}</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
配置檔案
##端口号
server.port=8762
##服務名稱
spring.application.name=service
##注冊中心位址
eureka.client.service-url.defaultZone=http://eureka.dalaoyang.cn/eureka/
啟動類使用注解@EnableEurekaClient向注冊中心注冊,代碼如下:
package com.dalaoyang;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
@SpringBootApplication
@RestController
@EnableEurekaClient
public class SpringcloudServiceApplication {
public static void main(String[] args) {
SpringApplication.run(SpringcloudServiceApplication.class, args);
}
@Value("${server.port}")
String port;
@Value("${spring.application.name}")
String serviceName;
@GetMapping("/")
public String index(){
return "serviceName=" + serviceName + "-------port=" + port;
}
}
到這裡service(8762)建立完成,然後複制一個項目,端口号改為8763作為service(8763)。
然後建立項目service-ribbon(8764),pom檔案加入ribbon依賴,pom完整代碼如下:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.dalaoyang</groupId>
<artifactId>springcloud_ribbon</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
<name>springcloud_ribbon</name>
<description>springcloud_ribbon</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.9.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
<spring-cloud.version>Edgware.SR1</spring-cloud.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-eureka</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-ribbon</artifactId>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>${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>
</project>
配置檔案如下:
##端口号
server.port=8764
##服務名稱
spring.application.name=service_ribbon
##注冊中心位址
eureka.client.service-url.defaultZone=http://eureka.dalaoyang.cn/eureka/
由于隻是一個簡單demo,所有我将java代碼都寫在了啟動類裡面,解釋一下,@LoadBalanced放在RestTemplate上面,表明RestTemplate開啟負載均衡。代碼如下:
package com.dalaoyang;
import org.springframework.beans.factory.annotation.Value;
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.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
@SpringBootApplication
@EnableEurekaClient
@RestController
public class SpringcloudRibbonApplication {
public static void main(String[] args) {
SpringApplication.run(SpringcloudRibbonApplication.class, args);
}
@Bean
@LoadBalanced
RestTemplate restTemplate() {
return new RestTemplate();
}
@Value("${server.port}")
String port;
@Value("${spring.application.name}")
String serviceName;
@GetMapping("/")
public String index(){
return restTemplate().getForObject("http://service/",String.class);
}
}
分别啟動service(8762),service(8763),service-ribbon(8764)三個工程。
先檢視
http://eureka.dalaoyang.cn/,可以看到三個執行個體注冊成功。如下圖:
image
多次通路
http://localhost:8764/,可以看到頁面交替顯示
可以看到負載均衡已經做到了。
完整項目流程如下圖:
源碼下載下傳 :
大老楊碼雲個人網站:
https://dalaoyang.cn