fegin服务调用

使用

1.加入依赖

  org.springframework.cloud
  spring-cloud-starter-openfeign

 2.在启动类上添加注解@EnableFeignClients

@SpringBootApplication
@EnableDiscoveryClient
@EnableFeignClients
public class OrderApplication {
    
    public static void main(String[] args) {
        SpringApplication.run(OrderApplication.class, args);
    }
    
    @Bean
    @LoadBalanced
    public RestTemplate getRestTemplate() {
        return new RestTemplate();
    }
}

3.定义接口,并写上注解@FeignClient,value写上服务名称

@FeignClient(
        value = "service-product",
        //fallback = ProductServiceFallBack.class,
        fallbackFactory = ProductServiceFallBackFactory.class)
public interface ProductService {
    
    //指定调用提供者的哪个方法
    //@FeignClient+@GetMapping 就是一个完整的请求路径 http://serviceproduct/product/{pid}
    @GetMapping(value = "/product/{pid}")
    Product findByPid(@PathVariable("pid") Integer pid);
}

4.在任意bean中注入即可使用

注解参数

fallbackFactory使用,定义容错处理,统一处理错误,需要实现 FallbackFactory接口

@Component
public class ProductServiceFallBackFactory implements FallbackFactory {
    
    @Override
    public ProductService create(Throwable throwable) {
        return pid -> {
            throwable.printStackTrace();
            Product product = new Product();
            product.setPid(-1);
            return product;
        };
    }
}

请求中加入头部信息

1.在定义的fegin接口中的RequestMapping注解加上headers 参数

@FeignClient(name="custorm",fallback=Hysitx.class)
public interface IRemoteCallService {
	@RequestMapping(value="/custorm/getTest",method = RequestMethod.POST,
		headers = {"Content-Type=application/json;charset=UTF-8"})
    List test(@RequestParam("names") String[] names);
}

2.在方法参数前面添加@RequestHeader注解,设置多个参数可以使用Map

@FeignClient(name="custorm",fallback=Hysitx.class)
public interface IRemoteCallService {
	@RequestMapping(value="/custorm/getTest",method = RequestMethod.POST)
    List test(@RequestParam("names")
                @RequestHeader("Authorization") 
                String[] names);
}

3.使用@Header注解

@FeignClient(name="custorm",fallback=Hysitx.class)
public interface IRemoteCallService {
	@RequestMapping(value="/custorm/getTest",method = RequestMethod.POST)
	@Headers({"Content-Type: application/json;charset=UTF-8"})
    List test(@RequestParam("names") String[] names);
}

4.实现RequestInterceptor接口

@Configuration
public class FeignRequestInterceptor implements RequestInterceptor {
 
    @Override
    public void apply(RequestTemplate temp) {
        temp.header(HttpHeaders.AUTHORIZATION, "XXXXX");
    }
}