一、配置文件解析器
服务提供者和消费者都需要配置文件解析器，这里使用 commons-fileupload 替换原有的解析器：
依赖：
<dependency> <groupId>commons-fileupload</groupId> <artifactId>commons-fileupload</artifactId> <version>1.3.1</version> </dependency>
注入 bean ：
@Bean(name = "multipartResolver")
public MultipartResolver mutipartResolver(){
CommonsMultipartResolver com = new CommonsMultipartResolver();
com.setDefaultEncoding("utf-8");
return com;
}
程序入口中剔除原有的解析器：
@SpringBootApplication(exclude = {MultipartAutoConfiguration.class})
二、服务提供者，即接收文件一方的配置
Controller 的写法：
@ResponseBody
@RequestMapping(value = "/upload", method = {RequestMethod.POST},
produces = {MediaType.APPLICATION_JSON_UTF8_VALUE},
consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
public Result<String> uploadFile(@RequestPart("file")MultipartFile file,
@RequestParam("id")Long id){
String fileName = file.getOriginalFilename();
String extend = FileOperateUtil.suffix(fileName);
FileOperateUtil.copy("E:\\" + fileName, file);
return ResultBuilder.success("ok");
}
@RequestPart 指定文件，后面的 @RequestParam 是额外参数，注意额外参数不能超过url长度限制。
三、服务消费者配置
依赖：
<dependency> <groupId>io.github.openfeign.form</groupId> <artifactId>feign-form-spring</artifactId> <version>3.2.2</version> </dependency> <dependency> <groupId>io.github.openfeign.form</groupId> <artifactId>feign-form</artifactId> <version>3.2.2</version> </dependency>
文件编码配置：
import feign.codec.Encoder;
import feign.form.spring.SpringFormEncoder;
import org.springframework.beans.factory.ObjectFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.autoconfigure.web.HttpMessageConverters;
import org.springframework.cloud.netflix.feign.support.SpringEncoder;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
@Configuration
public class MultipartSupportConfig{
@Autowired
private ObjectFactory<HttpMessageConverters> messageConverters;
@Bean
public Encoder feignFormEncoder(){
return new SpringFormEncoder(new SpringEncoder(messageConverters));
}
}
Feign 接口定义：
@FeignClient(name = "test-upload")
public interface UploadService{
@ResponseBody
@RequestMapping(value = "/upload", method = {RequestMethod.POST},
produces = {MediaType.APPLICATION_JSON_UTF8_VALUE},
consumes = MediaType.MULTIPART_FORM_DATA_VALUE)
Result<String>uploadFile(@RequestPart("file")MultipartFile file,
@RequestParam("id")Long id);
}
与普通 Feign 接口写法差不多，注意方法注解和参数与服务提供者的 controller 一样。
Controller 的写法， Controller 中接收前端传过来的文件信息和额外参数，然后通过 Feign 接口传输到远端：
// 注入 feign 接口
@Autowired
private UploadService uploadService;
@RequestMapping(value = "/upload", method = RequestMethod.POST, produces = "application/json; charset=utf-8")
@ResponseBody
public Result<String> testUpload(HttpServletRequest request, Long id){
Result<String> result = null;
MultipartHttpServletRequest mRequest = (MultipartHttpServletRequest) request;
Map<String, MultipartFile> fileMap = mRequest.getFileMap();
for (MultipartFile mFile : fileMap.values()) {
String fileName = mFile.getOriginalFilename();
result = uploadService.uploadFile(mFile, id);
}
return result;
}
四、总结
最后梳理一下流程，服务消费者接收前端（如浏览器）传过来的文件，但是并不进行业务处理，然后通过 Feign 调用接口，把文件传给服务提供者，服务提供者拿到文件后，进行相应的业务处理。
