在微服务架构中, 业务都会被拆分成一个独立的服务, 服务与服务的通讯是基于http restful的, Spring Cloud有两种服务调用方式, 一种是ribbon+restTemplate, 另一种是feign.
Ribbon简介
Ribbon是一个负载均衡客户端, 可以很好的控制http和tcp的一些行为。
准备工作
启动服务提供者, 端口号为: 8762
修改配置文件的端口号为: 8763, 启动后再Eureka中会注册两个实例, 相当于一个小集群
创建服务消费者
创建一个工程名为: hello-spring-cloud-web-admin-ribbon的服务消费者项目, pol.xml配置如下:
<?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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<parent>
<groupId>com.funtl</groupId>
<artifactId>hello-spring-cloud-dependencies</artifactId>
<version>1.0.0-SNAPSHOT</version>
<relativePath>../hello-spring-cloud-dependencies/pom.xml</relativePath>
</parent>
<artifactId>hello-spring-cloud-web-admin-ribbon</artifactId>
<packaging>jar</packaging>
<name>hello-spring-cloud-web-admin-ribbon</name>
<url>http://www.funtl.com</url>
<inceptionYear>2018-Now</inceptionYear>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-thymeleaf</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-actuator</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-netflix-eureka-server</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-ribbon</artifactId>
</dependency>
<dependency>
<groupId>net.sourceforge.nekohtml</groupId>
<artifactId>nekohtml</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
<configuration>
<mainClass>com.funtl.hello.spring.cloud.web.admin.ribbon.WebAdminRibbonApplication</mainClass>
</configuration>
</plugin>
</plugins>
</build>
</project>
主要是增加了Ribbon的依赖
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-netflix-ribbon</artifactId>
</dependency>
Application
通过@EnableDiscoveryClient注解注册到服务中心
package com.funtl.hello.spring.cloud.web.admin.ribbon;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
@EnableDiscoveryClient
@SpringBootApplication
public class WebAdminRibbonApplication {
public static void main(String[] args) {
SpringApplication.run(WebAdminRibbonApplication.class, args);
}
application.yml
设置程序端口号为: 8764
spring:
application:
name: hello-spring-cloud-web-admin-ribbon
thymeleaf:
cache: false
mode: LEGACYHTML5
encoding: UTF-8
servlet:
content-type: text/html
server:
port: 8764
eureka:
client:
serviceUrl:
defaultZone: http://localhost:8761/eureka/
Configuration
配置注入RestTemplate的Bean, 并通过@LoadBalanced注解表明开启负载均衡功能
package com.funtl.hello.spring.cloud.web.admin.ribbon.config;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;
@Configuration
public class RestTemplateConfiguration {
@Bean
@LoadBalanced
public RestTemplate restTemplate(){
return new RestTemplate();
}
}
创建测试用的Service
package com.funtl.hello.spring.cloud.web.admin.ribbon.service;
import com.netflix.discovery.converters.Auto;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.client.RestTemplate;
@Service
public class AdminService {
@Autowired
private RestTemplate restTemplate;
public String sayHi(String message){
return restTemplate.getForObject("http://hello-spring-cloud-service-admin/hi?message="+message, String.class);
}
}
创建测试用的Controller
package com.funtl.hello.spring.cloud.web.admin.ribbon.controller;
import com.funtl.hello.spring.cloud.web.admin.ribbon.service.AdminService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RestController;
@RestController
public class AdminController {
@Autowired
private AdminService adminService;
@RequestMapping(value="hi", method= RequestMethod.GET)
public String sayHi(String message){
return adminService.sayHi(message);
}
}
测试访问