feign是声明式的web service客户端，它让微服务之间的调用变得更简单了，类似controller调用service。Spring Cloud集成了Ribbon和Eureka，可在使用Feign时提供负载均衡的http客户端。
在springcloud中不仅可以使用Ribbo进行负载均衡，也可以使用Feign。Feign是在Ribbon的基础上进行了一次改进，采用接口的方式实现负载均衡。
org.springframework.cloud spring-cloud-starter-openfeign
@FeignClient(value = "PROVIDER-NAME")声明这是一个FeignClient，value指明需要的服务id
@FeignClient(value = "PROVIDER-NAME")
public interface DeptClientService {
// 请求的路径需与服务提供者的路径一致
@RequestMapping(value = "/dev/add")
boolean add(Dept dept);
@RequestMapping(value = "/dev/{id}")
Dept queryByID(@PathVariable("id") Long id );
@PostMapping(value = "/dev/list")
List queryAll();
}
我们不再使用RestTemplate来获取所需的对象，而是通过之前定义的接口来获取
@RestController
public class ConsumerController {
@Autowired
private DeptClientService service;
@RequestMapping("/consumer/get/{id}")
public Dept getByID(@PathVariable("id") Long id){
return this.service.queryByID(id);
}
@RequestMapping("/consumer/add")
public boolean add(String dname){
Dept dept = new Dept();
dept.setDname(dname);
return this.service.add(dept);
}
@RequestMapping("/consumer/list")
public List list(){
return this.service.queryAll();
}
}
@EnableFeignClients 开启Feign负载均衡
@SpringBootApplication(scanBasePackages = "com")
@EnableEurekaClient
@EnableFeignClients(basePackages = "com.service")
public class FeignApplication {
public static void main(String[] args) {
SpringApplication.run(FeignApplication.class,args);
}
}
Ribbon
public class ConsumerController {
@Autowired
private RestTemplate template;
private static final String url="http://PROVIDER-NAME";
@RequestMapping("/consumer/get/{id}")
public Dept getByID(@PathVariable long id){
//请求的路径，返回的对象
Dept getEntity = template.getForObject(url + "/dev/" + id, Dept.class);
return getEntity;
}
@RequestMapping("/consumer/add")
public boolean add(String dname){
Dept dept = new Dept();
dept.setDname(dname);
System.out.println(dept);
//请求的路径，传递的参数，返回的对象
return template.postForObject(url+ "/dev/add",dept,Boolean.class);
}
@RequestMapping("/consumer/list")
public List list(){
//请求的路径，返回的对象
return template.postForObject(url+"/dev/list",void.class,List.class);
}
}
Feign
@RestController
public class ConsumerController {
@Autowired
private DeptClientService service;
@RequestMapping("/consumer/get/{id}")
public Dept getByID(@PathVariable("id") Long id){
return this.service.queryByID(id);
}
@RequestMapping("/consumer/add")
public boolean add(String dname){
Dept dept = new Dept();
dept.setDname(dname);
return this.service.add(dept);
}
@RequestMapping("/consumer/list")
public List list(){
return this.service.queryAll();
}
}
Feign的使用与Ribbon不同的地方在于
以上就是SpringCloud Feign的使用简介的详细内容，更多关于SpringCloud Feign的资料请关注其它相关文章！
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