Gitee仓库
https://gitee.com/Lin_DH/system
介绍
文件上传是指将本地的图片、视频、音频等文件上传到服务器，供其他用户浏览下载的过程，文件上传在日常项目中用的非常广泛。
实现代码
第一步：在配置文件新增如下配置
application.yml
spring:servlet:multipart:max-file-size: 10MB #默认为1MB max-request-size: 10MB #默认为10MB
file:upload:path: F:/files/
第二步：编写文件上传页面
upload.html
<!DOCTYPE html>
<html lang="en">
<head lang="en"><meta charset="UTF-8" /><title>文件上传页面</title>
</head>
<body>
<h1>文件上传页面</h1>
<form method="post" action="/upload" enctype="multipart/form-data">选择要上传的txt格式文件：<input type="file" name="file"><br><hr><input type="submit" value="提交">
</form>
</body>
</html>
第三步：编写文件上传页面和对应接口
FileController.java
package com.lm.system.controller;import com.lm.system.exception.FileException;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Controller;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;import java.io.File;
import java.io.IOException;
import java.nio.file.Files;/*** @author DUHAOLIN* @date 2024/10/15*/
@Controller
public class FileController {private final static String FILE_FORMAT_TXT = "txt";@Value("${file.upload.path}")private String path;@GetMapping("uploadPage")public String uploadPage() {return "upload";}@PostMapping("upload")@ResponseBodypublic String upload(@RequestParam("file") MultipartFile file) throws IOException {//校验文件try {String[] fileFormats = { FILE_FORMAT_TXT };checkFile(file, fileFormats);} catch (FileException e) {e.printStackTrace();return e.getMessage();}String filename = path + file.getOriginalFilename().replace(FILE_FORMAT_TXT, "_" + System.currentTimeMillis() + FILE_FORMAT_TXT);File newFile = new File(filename);Files.copy(file.getInputStream(), newFile.toPath());return "新文件已生成，" + newFile.getAbsolutePath();}private void checkFile(MultipartFile file, String[] fileFormats) {//校验文件大小checkSize(file.getSize());//校验文件名checkFilename(file.getOriginalFilename());//校验文件格式checkFileFormat(file.getOriginalFilename(), fileFormats);}private void checkSize(long size) {if (size > 10485760L) //10MBthrow new FileException("文件大于10MB");}private void checkFilename(String filename) {if (!StringUtils.hasText(filename))throw new FileException("文件名有误");}private void checkFileFormat(String filename, String[] fileFormats) {int i = filename.lastIndexOf(".");String suffix = filename.substring(i + 1); //文件后缀long c = Arrays.stream(fileFormats).filter(s -> s.equals(suffix)).count(); //判断是否存在该文件后缀if (c < 1) throw new FileException("文件格式有误，该文件类型为：" + suffix);}}第四步：添加文件异常类
FileException.java
package com.lm.system.exception;/*** @author DUHAOLIN* @date 2024/10/15*/
public class FileException extends RuntimeException {public FileException() {super();}public FileException(String message) {super(message);}public FileException(String message, Throwable cause) {super(message, cause);}
}效果图
上传不正确的非 .txt 格式的文件
上传确认的 .txt 文件
项目结构图
