在Spring Cloud 的Feign组件中并不支持文件的传输，会出现这样的错误提示：
feign.codec.EncodeException: class [Lorg.springframework.web.multipart.MultipartFile; is not a type supported by this encoder. at feign.codec.Encoder$Default.encode(Encoder.java:90) ~[feign-core-9.5.1.jar:na] at feign.form.FormEncoder.encode(FormEncoder.java:87) ~[feign-form-3.3.0.jar:3.3.0] at feign.form.spring.SpringFormEncoder.encode(SpringFormEncoder.java:64) ~[feign-form-spring-3.3.0.jar:3.3.0]
但是我们可以通过使用Feign的扩展包实现这个功能。
一. 示例介绍
| 服务名 | 端口号 | 角色 |
| feign_upload_first | 8100 | feign服务提供者 |
| feign_upload_second | 8101 | feign服务消费者 |
我们调用feign_upload_second的上传文件接口上传文件，feign_upload_second内部使用feign调用feign_upload_first实现文件上传。
二 、单文件上传
2.1 feign_upload_first服务提供者
文件上传的服务提供者接口比较简单，如下所示：
@SpringBootApplication public class FeignUploadFirstApplication { @RestController public class UploadController { @RequestMapping(value = "/uploadFile",method = RequestMethod.POST, consumes = MediaType.MULTIPART_FORM_DATA_VALUE) public String handleFileUpload(@RequestPart(value = "file") MultipartFile file) { return file.getOriginalFilename(); } } public static void main(String[] args) { SpringApplication.run(FeignUploadFirstApplication.class, args); } }
2.2 feign_upload_second服务消费者
- 增加扩展包依赖，依赖包不能太高级，会报错
<dependency> <groupId>io.github.openfeign.form</groupId> <artifactId>feign-form</artifactId> <version>3.3.0</version> </dependency> <dependency> <groupId>io.github.openfeign.form</groupId> <artifactId>feign-form-spring</artifactId> <version>3.3.0</version> </dependency> <dependency> <groupId>commons-fileupload</groupId> <artifactId>commons-fileupload</artifactId> <version>1.3.3</version> </dependency> - 新增feign实现文件上传的配置类
import feign.codec.Encoder; import feign.form.spring.SpringFormEncoder; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; @Configuration public class FeignSupportConfig { @Bean public Encoder feignFormEncoder() { return new SpringFormEncoder(); } }
- feign远程调用接口
@FeignClient(name = "file",url = "http://localhost:8100",configuration = FeignSupportConfig.class) public interface UploadService { @RequestMapping(value = "/uploadFile", consumes = MediaType.MULTIPART_FORM_DATA_VALUE) String handleFileUpload(@RequestPart(value = "file") MultipartFile file); }
- 上传文件接口
@RestController public class UploadController { @Autowired UploadService uploadService; @RequestMapping(value = "/uploadFile",method = RequestMethod.POST, consumes = MediaType.MULTIPART_FORM_DATA_VALUE) public String handleFileUpload(@RequestPart(value = "file") MultipartFile file) { return uploadService.handleFileUpload(file); } }
2.3 测试
使用postman进行测试，可以正常上传文件