原文网址：Knife4j系列--解决不显示文件上传的问题_IT利刃出鞘的博客-CSDN博客

简介

本文介绍使用Knife4j时无法上传文件的问题。

问题复现

依赖

<dependency><groupId>com.github.xiaoymin</groupId><artifactId>knife4j-spring-boot-starter</artifactId><version>3.0.3</version>
</dependency>

代码

package com.example.demo.business.controller;import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;@Api(tags = "文件")
@RestController
@RequestMapping("file")
public class FileController {@ApiOperation("上传文件")@PostMapping("upload")public void upload(MultipartFile file) {}
}

结果

 ​​​

可以看到，无法上传文件。 

解决方案

在入参上添加注解@RequestPart

package com.example.demo.business.controller;import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestPart;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;@Api(tags = "文件")
@RestController
@RequestMapping("file")
public class FileController {@ApiOperation("上传文件")@PostMapping("upload")public void upload(@RequestPart MultipartFile file) {}
}

结果

备注

网上有人说需要在方法上加@ApiImplicitParam注解，如下：

package com.example.demo.business.controller;import io.swagger.annotations.Api;
import io.swagger.annotations.ApiImplicitParam;
import io.swagger.annotations.ApiOperation;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestPart;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;@Api(tags = "文件")
@RestController
@RequestMapping("file")
public class FileController {@ApiOperation("上传文件")@PostMapping("upload")@ApiImplicitParam(name = "file", dataTypeClass = MultipartFile.class, paramType = "form")public void upload(@RequestPart MultipartFile file) {}
}

经我测试，这个不需要加。只在参数上加@RequestPart即可。