在上節使用Nacos實現服務注冊與發現中我們簡單的利用了Nacos的其中最基礎的特性完成了應用的注冊和發現,也簡單的通過接口來實現了consumer來調用producer的過程,這節我們來看看如何通過聲明式的工具來調用我們的服務提供者,常見的是通過RestTemplate. feign以及webflux等,這節我們只來看看后面的兩種.
使用feign的方式
關于什么是Feign?,這里就不在啰嗦了,實質上就是一個微服務之間的聲明式調用的工具,詳情可以去看看springcloud官網,首先在上節的項目中創建一個名為alibaba-nacos-client-feign的子模塊項目.
- pom文件中需要添加對應的依賴,代碼如下;
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-openfeign</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Greenwich.SR1</version>
<type>pom</type>
<scope>import</scope>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-alibaba-dependencies</artifactId>
<version>0.2.2.RELEASE</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
- 其次我們需要定義feign客戶端,代碼如下;
package com.cacmp.alibaba.nacos.client.service;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestParam;
/**
* @author cb
*/
@FeignClient(name = "alibaba-nacos-producer")
public interface FeignService {
@GetMapping("hello")
String hello(@RequestParam String name);
注解FeignClient其主要的目的是為了來指定要調用的那個服務名稱,接口中我們只需要綁定要調用服務的rest接口,如上述代碼中我們服務alibaba-nacos-producer的hello接口......
- 來看我們的配置文件,代碼如下:
server:
port: 9001
spring:
application:
name: alibaba-nacos-client-feign
cloud:
nacos:
discovery:
server-addr: localhost:8848
- 最后來看我們的啟動類,代碼如下:
package com.cacmp.alibaba.nacos.client;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.openfeign.EnableFeignClients;
/**
* @author cb
*/
@SpringBootApplication
@EnableDiscoveryClient
@EnableFeignClients
public class AlibabaNacosClientFeignApplication {
public static void main(String[] args) {
SpringApplication.run(AlibabaNacosClientFeignApplication.class, args);
}
同樣,我們將該服務注冊到了我們的Nacos注冊中心中,當然我們作為feign客戶端,就需要貼上@EnableFeignClients注解,我們啟動我們的服務alibaba-nacos-producer來作為服務的提供者,而alibaba-nacos-client-feign來調用,訪問http://localhost:9001/test后,會得到hello:Nacos!的結果,關于feign的講解我們就到這里,接下來看webflux
webflux
關于webflux的講解,這里不說,想了解的可以自己去看看,據說是用來替代springmvc的,兩者可以對比去看,這里我們直接用就可以了,來看:
首先我們來創建一個alibaba-nacos-client-webflux項目,在pom文件中需要引入對應的依賴,代碼如下:
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-webflux</artifactId>
</dependency>
</dependencies>
<dependencyManagement>
<dependencies>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-dependencies</artifactId>
<version>Greenwich.SR1</version>
<type>pom</type>
<scope>import</scope>
</dependency>
<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-alibaba-dependencies</artifactId>
<version>0.2.2.RELEASE</version>
<type>pom</type>
<scope>import</scope>
</dependency>
</dependencies>
</dependencyManagement>
這里不再需要web的依賴了,接著我們來看配置文件,代碼如下:
server:
port: 9002
spring:
application:
name: alibaba-nacos-client-webflux
cloud:
nacos:
discovery:
server-addr: localhost:8848
再來看啟動類,代碼入下:
package com.cacmp.alibaba.nacos.client;
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.reactive.function.client.WebClient;
/**
* @author cb
*/
@SpringBootApplication
@EnableDiscoveryClient
public class AlibabaNacosClientWebfluxApplication {
public static void main(String[] args) {
SpringApplication.run(AlibabaNacosClientWebfluxApplication.class, args);
}
@Bean
@LoadBalanced
public WebClient.Builder webClientBuilder(){
return WebClient.builder();
}
來看我們的接口類,代碼如下:
package com.cacmp.alibaba.nacos.client.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.reactive.function.client.WebClient;
import reactor.core.publisher.Mono;
/**
* @author cb
*/
@RestController
public class WebFluxController {
@Autowired
private WebClient.Builder webBuilder;
@RequestMapping("test")
public Mono<String> testWebFlux(){
String uri = "http://alibaba-nacos-producer";
Mono<String> mono = webBuilder.build()
.get()
.uri(uri + "/hello?name=" + "Nacos!")
.retrieve()
.bodyToMono(String.class);
System.out.println(mono);
return mono;
}
啟動我們的服務,訪問http://127.0.0.1:9002/test,會得到hello:Nacos!的結果,以上就是webflux的簡單使用.
