Spring Cloud Feign的文件上傳實現(xiàn)

在Spring Cloud封裝的Feign中并不直接支持傳文件，但可以通過引入Feign的擴(kuò)展包來實現(xiàn)，本來就來具體說說如何實現(xiàn)。

服務(wù)提供方（接收文件）

服務(wù)提供方的實現(xiàn)比較簡單，就按Spring MVC的正常實現(xiàn)方式即可，比如：

@EnableFeignClients
@EnableDiscoveryClient
@SpringBootApplication
public class Application {

   @RestController
   public class UploadController {

       @PostMapping(value = "/uploadFile", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
       public String handleFileUpload(@RequestPart(value = "file") MultipartFile file) {
           return file.getName();
       }

   }

   public static void main(String[] args) {
       new SpringApplicationBuilder(Application.class).web(true).run(args);
   }

}
   

服務(wù)消費方（發(fā)送文件）

在服務(wù)消費方由于會使用Feign客戶端，所以在這里需要在引入feign對表單提交的依賴，具體如下：

<dependency>
  <groupId>io.github.openfeign.form</groupId>
  <artifactId>feign-form</artifactId>
  <version>3.0.3</version>
</dependency>
<dependency>
  <groupId>io.github.openfeign.form</groupId>
  <artifactId>feign-form-spring</artifactId>
  <version>3.0.3</version>
</dependency>
<dependency>
  <groupId>commons-fileupload</groupId>
  <artifactId>commons-fileupload</artifactId>
  <version>1.3.3</version>
</dependency>
   

定義文件上傳方的應(yīng)用主類和FeignClient，假設(shè)服務(wù)提供方的服務(wù)名為eureka-feign-upload-server

@EnableFeignClients
@EnableDiscoveryClient
@SpringBootApplication
public class Application {

   public static void main(String[] args) {
       new SpringApplicationBuilder(Application.class).web(true).run(args);
   }

}

@FeignClient(value = "upload-server", configuration = UploadService.MultipartSupportConfig.class)
public interface UploadService {

   @PostMapping(value = "/uploadFile", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
   String handleFileUpload(@RequestPart(value = "file") MultipartFile file);

   @Configuration
   class MultipartSupportConfig {
       @Bean
       public Encoder feignFormEncoder() {
           return new SpringFormEncoder();
       }
   }

}
   

在啟動了服務(wù)提供方之后，嘗試在服務(wù)消費方編寫測試用例來通過上面定義的Feign客戶端來傳文件，比如：

@Slf4j
@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest
public class UploadTester {

   @Autowired
   private UploadService uploadService;

   @Test
   @SneakyThrows
   public void testHandleFileUpload() {

       File file = new File("upload.txt");
       DiskFileItem fileItem = (DiskFileItem) new DiskFileItemFactory().createItem("file",
               MediaType.TEXT_PLAIN_VALUE, true, file.getName());

       try (InputStream input = new FileInputStream(file); OutputStream os = fileItem.getOutputStream()) {
           IOUtils.copy(input, os);
       } catch (Exception e) {
           throw new IllegalArgumentException("Invalid file: " + e, e);
       }

       MultipartFile multi = new CommonsMultipartFile(fileItem);

       log.info(uploadService.handleFileUpload(multi));
   }

}