上篇文章记录了服务的注册与发现,这篇要记录一下关于springcloud的服务消费部分。
springcloud服务调用有两种方式,一种是基于ribbon+restTemplate另一种是基于Feign。
ribbon+restTemplate
首先基于上篇文章的服务注册中心和服务提供者项目,来辅助完成今天的服务消费项目。先启动服务注册中心项目,再启动服务提供者项目,服务提供者的实例需要跑两个(在intellij idea中右上角有个edit configuration,点击后有single instance only,取消勾选就可以跑多个工程实例了)。然后新建一个Maven项目,pom文件如下:
<?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>ribbon</groupId> <artifactId>ribbon</artifactId> <version>1.0-SNAPSHOT</version> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.4.0.RELEASE</version> </parent> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-eureka</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-ribbon</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</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>Dalston.RC1</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> <snapshots> <enabled>false</enabled> </snapshots> </repository> </repositories> </project>
在resources下创建配置文件application.yml,如下:
eureka: client: serviceUrl: defaultZone: http://localhost:8761/eureka/ server: port: 8764 spring: application: name: ribbon
创建工程的启动类,开启负载均衡,代码如下:
package ribbon; import org.springframework.beans.factory.annotation.Autowired; 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.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.RestController; import org.springframework.web.client.RestTemplate; import ribbon.service.HelloService; @SpringBootApplication @EnableDiscoveryClient @RestController public class RibbonApplication { public static void main(String[] args) { SpringApplication.run(RibbonApplication.class, args); } @Bean @LoadBalanced RestTemplate restTemplate() { return new RestTemplate(); } @Autowired HelloService helloService; @RequestMapping(value = "/hi") public String hi(@RequestParam String name){ return helloService.hiService(name); } }
还要创建一个服务消费的Service,代码如下:
package ribbon.service; 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://springcloud-client/hi?name="+name,String.class); } }
其中springcloud-client为服务提供者的名称。
最后,运行启动类,此时在浏览器访问http://localhost:8761会出现如下界面:
在浏览器多次访问http://localhost:8764hi?name=aaa会出现如下的结果,证明ribbon的负载均衡已起作用。
Feign
准备工作与上面一样,创建一个Maven项目,pom文件如下:
<?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>feign</groupId> <artifactId>feign</artifactId> <version>1.0-SNAPSHOT</version> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>1.4.0.RELEASE</version> <relativePath/> <!-- lookup parent from repository --> </parent> <dependencies> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-eureka</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-feign</artifactId> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</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>Dalston.RC1</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> <snapshots> <enabled>false</enabled> </snapshots> </repository> </repositories> </project>
在resources下创建application.yml配置文件,如下:
eureka: client: serviceUrl: defaultZone: http://localhost:8761/eureka/ server: port: 8765 spring: application: name: feign
创建一个启动类,如下:
package feign; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; import org.springframework.cloud.client.discovery.EnableDiscoveryClient; import org.springframework.cloud.netflix.feign.EnableFeignClients; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RequestParam; import org.springframework.web.bind.annotation.RestController; @SpringBootApplication @EnableDiscoveryClient @EnableFeignClients @RestController public class ServiceFeignApplication { public static void main(String[] args) { SpringApplication.run(ServiceFeignApplication.class, args); } @Autowired SchedualServiceHi schedualServiceHi; @RequestMapping(value = "/hi") public String sayHi(@RequestParam String name){ return schedualServiceHi.sayHiFromClientOne(name); } }
以及一个服务消费的Service,如下:
package feign; import org.springframework.cloud.netflix.feign.FeignClient; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.RequestMethod; import org.springframework.web.bind.annotation.RequestParam; @FeignClient(value = "SPRINGCLOUD-CLIENT") public interface SchedualServiceHi { @RequestMapping(value = "/hi",method = RequestMethod.GET) String sayHiFromClientOne(@RequestParam(value = "name") String name); }
其中,@FeignClient(value = "SPRINGCLOUD-CLIENT")中value值为服务提供者名称。
在运行启动类后,访问http://localhost:8761页面,显示如下:
在浏览器多次访问localhost:8765/hi?name=bbb,会有如下结果响应,说明负载均衡功能已启用。