文件上传-下载

配置文件

spring:
  servlet:
    multipart:
      enabled: true
      max-file-size: 10MB
      max-request-size: 20MB

# 文件存储路径
file:
  upload-dir: ./src/main/resources/static/uploads

开启资源映射

上传即时生效，无需重启项目

package com.AssetTrack.config;

import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;

@Configuration
public class WebConfig implements WebMvcConfigurer {

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        // 将 /uploads/** 映射到 resources/static/uploads/ 目录
        registry.addResourceHandler("/uploads/**")
                .addResourceLocations("file:src/main/resources/static/uploads/");
    }
}

服务接口

package com.AssetTrack.service;

import org.springframework.beans.factory.annotation.Value;
import org.springframework.core.io.Resource;
import org.springframework.core.io.UrlResource;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;

import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;

@Service
public class FileService {
    @Value("${file.upload-dir}")
    private String uploadDir;

    public Resource getFileAsResource(String fileName) throws Exception {
        Path filePath = Paths.get(uploadDir).resolve(fileName).normalize();
        Resource resource = new UrlResource(filePath.toUri());
        if (resource.exists() && resource.isReadable()) {
            return resource;
        } else {
            throw new Exception("File not found or not readable: " + fileName);
        }
    }

    public String uploadFile(MultipartFile file) throws IOException {
        // 确保目录存在
        Path uploadPath = Paths.get(uploadDir);
        if (!Files.exists(uploadPath)) {
            Files.createDirectories(uploadPath);
        }
        // 保存文件
        String fileName = file.getOriginalFilename();
        int lastIndex = fileName.lastIndexOf('.');
        String prefix;
        String suffix = "";
        if (lastIndex > 0) {
            prefix = fileName.substring(0, lastIndex);
            suffix = fileName.substring(lastIndex);
        } else {
            prefix = fileName;
        }
        fileName = prefix + "_" + System.currentTimeMillis() + suffix;
        Path filePath = uploadPath.resolve(fileName);
        file.transferTo(filePath);
        return fileName;
    }
}

控制器示例

package com.base.controller;

import com.base.service.FileService;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.core.io.Resource;
import org.springframework.http.HttpHeaders;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.*;
import org.springframework.web.multipart.MultipartFile;

@RestController
@RequestMapping("/file")
@CrossOrigin
@Api(tags = "文件操作")
public class FileController {

    @Autowired
    FileService fileService;

    @PostMapping("/upload")
    @ApiOperation("上传")
    public ResponseEntity<String> uploadFile(
            @RequestParam("file") MultipartFile file
    ) {
        try {
            // 保存文件
            String fileName = fileService.uploadFile(file);
            fileService.uploadFile(file);

            return ResponseEntity.ok("File uploaded successfully: " + fileName);
        } catch (Exception e) {
            return ResponseEntity.status(500).body("Failed to upload file: " + e.getMessage());
        }
    }


    @GetMapping("/download/{fileName}")
    @ApiOperation("下载")
    public ResponseEntity<Resource> downloadFile(@PathVariable String fileName) {
        try {
            Resource resource = fileService.getFileAsResource(fileName);
            return ResponseEntity.ok()
                    .header(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=\"" + resource.getFilename() + "\"")
                    .body(resource);
        } catch (Exception e) {
            return ResponseEntity.status(404).body(null);
        }
    }

}