1.封装文件工具类FileUtils


import .IOUtils;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.multipart.MultipartFile;

import java.io.*;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.UUID;

public class FileUtils {



    /**
     * 上传文件到本地服务器，并返回文件的全路径。
     *
     * @param basePath  文件保存的基础路径
     * @param file      待上传的文件
     * @return          上传后文件的全路径
     */
    public String uploadFile(String basePath, MultipartFile file) {
        try {
            // 确保basePath以路径分隔符结尾，如果不是则添加
            if (!basePath.endsWith(File.separator)) {
                basePath += File.separator;
            }

            // 生成唯一的文件名，防止重名覆盖
            String originalFilename = file.getOriginalFilename();
            String uniqueFileName = UUID.randomUUID().toString() + "_" + originalFilename;
            Path uploadPath = Paths.get(basePath, uniqueFileName);

            // 创建文件夹路径（如果不存在）
            Files.createDirectories(uploadPath.getParent());

            // 将上传的文件保存到服务器
            Files.copy(file.getInputStream(), uploadPath);

            // 返回文件的全路径
            return uploadPath.toString();
        } catch (IOException e) {
            // 处理文件上传过程中可能出现的IO异常
            e.printStackTrace();
            throw new RuntimeException("文件上传失败", e);
        }
    }

    /**
     * 输出指定文件的byte数组
     *
     * @param filePath 文件路径
     * @param os 输出流
     * @return
     */
    public static void writeBytes(String filePath, OutputStream os) throws IOException
    {
        FileInputStream fis = null;
        try
        {
            File file = new File(filePath);
            if (!file.exists())
            {
                throw new FileNotFoundException(filePath);
            }
            fis = new FileInputStream(file);
            byte[] b = new byte[1024 * 10];
            int length;
            while ((length = fis.read(b)) > 0)
            {
                os.write(b, 0, length);
                os.flush();
            }
        }
        catch (IOException e)
        {
            throw e;
        }
        finally
        {
            IOUtils.closeQuietly(os);
            IOUtils.closeQuietly(fis);
        }
    }
}

2.service层业务方法调用，要先在yml配置好上传路径


  @Value("${web.upload-path}")
    private String uploadPath;

    public String uploadFile(MultipartFile file, HttpServletRequest request) {
            FileUtils fileUtils = new FileUtils();
            String filePath = fileUtils.uploadFile(uploadPath, file);
 	    return filePath;
    }

}

3.controller层接口

 @PostMapping("uploadFile")
    public Result uploadFile(@RequestBody MultipartFile file, HttpServletRequest request) {
        try {
            String filePath = filesService.uploadFile(file, request);
            return new Result().ok().setData(filePath);
        } catch (Exception e) {
            e.printStackTrace();
            return  new Result().err();
        }
    }

4.前端代码实现

               <el-form-item label="交付物：" prop="file">
                        <el-upload ref="uploadRef" class="upload-demo" action="/sys/files/uploadFile"
                            :on-success="handleFile" :on-remove="handleRemove" :limit="1" :file-list="fileList"
                            :auto-upload="false" :on-exceed="handleExceed">
                            <template #trigger>
                                <el-button type="primary" icon="el-icon-upload">请选择文件</el-button>
                            </template>
                            <el-button type="success" @click="submitUpload">上传</el-button>
                            <template #tip>
                                <div class="el-upload__tip" style="color: hsla(60, 59%, 49%, 0.962)">
                                    tip：文件大小不要超过2M
                                </div>
                            </template>
                        </el-upload>
                    </el-form-item>

效果如下

1008.gif