【SpringBoot】16 文件上传（Thymeleaf + MySQL）

news2024/11/26 0:32:12

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")
    @ResponseBody
    public 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) //10MB
            throw 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);
    }
}