在Spring Cloud封装的Feign中并不直接支持传文件，但可以通过引入Feign的扩展包来实现，本来就来具体说说如何实现。
服务提供方（接收文件）
服务提供方的实现比较简单，就按Spring MVC的正常实现方式即可，比如：
@RestController
public class UploadController {
@PostMapping(value = "/uploadFile", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
public String handleFileUpload(@RequestPart(value = "file") MultipartFile file) {
return file.getName();
}
}
服务消费方（发送文件）
在服务消费方由于会使用Feign客户端，所以在这里需要在引入feign对表单提交的依赖，具体如下：
<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> </dependency>
定义FeignClient，假设服务提供方的服务名为 upload-server
@FeignClient(value = "upload-server", configuration = TestServiceClient.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();
}
}
}
在启动了服务提供方之后，尝试在服务消费方编写测试用例来通过上面定义的Feign客户端来传文件，比如：
@Test
@SneakyThrows
public void testHandleFileUpload() {
File file = new File("files/aaa.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(testServiceClient.handleFileUpload(multi));
}
