Feign之Multipartfile文件传输填坑

Multipartfile文件传输

1. 添加依赖

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									<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>

2. 添加配置类

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									@Configuration

									public class FeignMultipartConfig {

									    @Bean

									    @Primary

									    @Scope("prototype")

									    public SpringFormEncoder multipartFormEncoder() {

									        return new SpringFormEncoder();

									    }

									    @Bean

									    public feign.Logger.Level multipartLoggerLevel() {

									        return feign.Logger.Level.FULL;

									    }

									}

3. 接口编写

@FeignClient使用配置类

@PostMapping设置

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									consumes = MediaType.MULTIPART_FORM_DATA_VALUE

使用@RequestPart(),不能使用@RequestParam()

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									@FeignClient(value = "face-service",configuration = FeignMultipartConfig.class)

									public interface FaceClient {

									 @PostMapping(value = "/search/student", consumes = MediaType.MULTIPART_FORM_DATA_VALUE)

									    ResponseBase<SearchStudentFaceVO> searchStudentFace(@RequestPart("file") MultipartFile file);

									}

feign不能正常传递参数MultipartFile（文件）的解决

之前工作中有个业务场景：需要把文件以MultipartFile进行服务之间的调用（使用的是Feign），特此记录下踩到的坑

需要注意的是：使用默认的springcloud自带的spring-cloud-starter-openfeign是不支持传递文件的。

我看网上有很多使用feign-form和feign-form-spring支持的jar包，然后配置SpringFormEncoder，但我试了，没有成功，最后使用了另外一种方法，在此记录下吧：

方法一：使用外部依赖

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									<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>

新建配置类：

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									package com.jsyd.ict.ictservicemanager.configuration;

									import org.springframework.beans.factory.ObjectFactory;

									import org.springframework.beans.factory.annotation.Autowired;

									import org.springframework.boot.autoconfigure.http.HttpMessageConverters;

									import org.springframework.cloud.openfeign.support.SpringEncoder;

									import org.springframework.context.annotation.Bean;

									import feign.codec.Encoder;

									import feign.form.spring.SpringFormEncoder;

									import org.springframework.context.annotation.Configuration;

									/**

									 * 处制定了注入的feignFormEncoder可以覆盖掉原本的encoder

									 * 该方式可以让发送multipartFile成为可能

									 * @author wangyang

									 * @version 1.0

									 * @date 2021/4/13 19:13

									 */

									@Configuration

									public class MultipartSupportConfig {

									    @Autowired

									    private ObjectFactory<HttpMessageConverters> messageConverters;

									    @Bean

									    public Encoder feignFormEncoder() {

									        return new SpringFormEncoder(new SpringEncoder(messageConverters));

									    }

									}

配置feign接口：

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									package com.jsyd.ict.ictservicemanager.feign;

									import com.jsyd.ict.ictservicemanager.util.resp.RespUtil;

									import org.springframework.cloud.openfeign.FeignClient;

									import org.springframework.http.MediaType;

									import org.springframework.web.bind.annotation.*;

									import org.springframework.web.multipart.MultipartFile;

									import java.io.BufferedInputStream;

									import java.io.File;

									import java.io.InputStream;

									/**

									 * 能力的调用

									 *

									 * @author wangyang

									 * @version 1.0

									 * @date 2021/3/11 21:01

									 */

									@FeignClient(name = "ict-service-capacity", configuration = MultipartSupportConfig.class)

									public interface CapacityFeign {

									    @RequestMapping(value = "contentAudit/baiduImgAuditByFile", method = RequestMethod.POST, consumes = MediaType.MULTIPART_FORM_DATA_VALUE)

									    RespUtil baiduImgAuditByFile(@RequestPart(value = "file") MultipartFile file);

									}

注意：文件的传输需要使用@RequestPart()注解

服务端：

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									  @RequestMapping(value = "/baiduImgAuditByFile", method = RequestMethod.POST)

									  public RespUtil baiduImgAuditByFile(@RequestParam("file") MultipartFile file)  {

									// 调用service

									      return null;

									  }

结果发现，这样是获取不到结果的，研究了好一会，因为要着急联调，就没有继续跟踪了，有时间在深入研究下。

后来使用了下面的方法，成功传参

方法二：使用HttpServletRequest获取

上述操作都不需要，即：不需要导入依赖，也不需要创建文件，只需要在服务端通过HttpServletRequest去设置

使用HttpServletRequest设置：

伪代码如下：

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									@RequestMapping(value = "/baiduImgAuditByFile", method = RequestMethod.POST)

									public RespUtil baiduImgAuditByFile(MultipartFile file, HttpServletRequest request) {

									    if (file == null) {

									        // 解决服务间调用无法接受MultipartFile参数的问题

									        String contentType = request.getContentType();

									        if (contentType != null && contentType.toLowerCase().startsWith("multipart/")) {

									            MultipartHttpServletRequest multipartRequest =

									                    WebUtils.getNativeRequest(request, MultipartHttpServletRequest.class);

									            if (multipartRequest != null) {

									                MultiValueMap<String, MultipartFile> multiFileMap = multipartRequest.getMultiFileMap();

									                for (Map.Entry<String, List<MultipartFile>> entry : multiFileMap.entrySet()) {

									                    file = entry.getValue().get(0);

									                }

									            }

									        }

									    }

									    // 处理业务逻辑

									    return null;

									}