SpringBoot之文件上传与下载

前言

利用springboot2，我们可以很方便的弄上传和下载，今天刚刚好有个功能模块用到，所以share一下这个功能。

Controller控制器

控制器方面，只需要一个封装返回类（例如我用的ApiReturnUtil.success()/Reselt.ok()等，自行封装即可）、配置类（配置一下上传的路径以及映射出去的文件路径）、控制器主类（包含上传和下载的方法）即可。

@RestController
@RequestMapping("/image")
/**
 * 文件上传控制器
 * @author zhengkai.blog.csdn.net
 **/
public class ImageController {

	@Autowired
	private MyProps myProps;

	@PostMapping("save")
	public ApiReturnObject save(@RequestParam("file") MultipartFile file,@RequestParam String checkNum,@RequestParam String facilityTypeNum) {
		String fileName ="";
		if(!file.isEmpty()){
			if(!file.getOriginalFilename().contains(".")){
				return ApiReturnUtil.error("上传失败:文件没有后缀名");
			}
			//文件名=设备类型-时间戳.后缀
			fileName = facilityTypeNum.toUpperCase()+"-"+System.currentTimeMillis()+file.getOriginalFilename().substring(file.getOriginalFilename().lastIndexOf('.'));
			String saveFileName = myProps.imagePath +checkNum+File.separator+fileName;
			System.out.println(saveFileName);
			File dest = new File(saveFileName);
			if(!dest.getParentFile().exists()){
				//判断文件父目录是否存在
				dest.getParentFile().mkdirs();
			}
			try {
				file.transferTo(dest);
				//保存文件
			} catch (Exception e) {
				e.printStackTrace();
				return ApiReturnUtil.error("上传失败:"+e.getMessage());
			}
		}else {
			return ApiReturnUtil.error("上传失败:文件不存在");
		}
		Map<String,Object> returnMap=new HashMap<>(4);
		//返回的时候把各种属性都返回即可
		returnMap.put("imageUrl",myProps.getImageUrl()+checkNum+"/"+fileName);
		returnMap.put("fileName","/"+checkNum+"/"+fileName);
		returnMap.put("checkNum",checkNum);
		returnMap.put("facilityTypeNum",facilityTypeNum);
		return ApiReturnUtil.success(returnMap);
	}
	@RequestMapping("/download")
	public Object download(HttpServletResponse response,@RequestParam String fileName) {
		File file = new File( myProps.imagePath+fileName);
		if (file.exists()) {
			response.setContentType("application/force-download");
			// 设置强制下载不打开
			response.addHeader("Content-Disposition", "attachment;fileName=" + fileName);
			byte[] buffer = new byte[1024];
			FileInputStream fis = null;
			BufferedInputStream bis = null;
			try {
				fis = new FileInputStream(file);
				bis = new BufferedInputStream(fis);
				OutputStream outputStream = response.getOutputStream();
				int i = bis.read(buffer);
				while (i != -1) {
					outputStream.write(buffer, 0, i);
					i = bis.read(buffer);
				}
				return "下载成功";
			} catch (Exception e) {
				e.printStackTrace();
			} finally {
				if (bis != null) {
					try {
						bis.close();
					} catch (IOException e) {
						e.printStackTrace();
					}
				}
				if (fis != null) {
					try {
						fis.close();
					} catch (IOException e) {
						e.printStackTrace();
					}
				}
			}
		}
        return ApiReturnUtil.error("文件不存在");
    }
}

MyProps路径配置

imageUrl是上传后前缀补全路径，例如imageUrl=http://127.0.0.1:9999/你上传了个a.jpg在aaa目录下，那么就是imageUrl/aaa/a.jpg

@Component  
@ConfigurationProperties(prefix="system") //接收application.yml中的myProps下面的属性  
@Data
public class MyProps {
	public String imageUrl;
	public String imagePath;
}

application.yml配置

imagePath是本地存储主目录，linux的话是/xxx/xxx
imageUrl是项目的路径或者其他待映射路径

system:
    imageUrl: http://127.0.0.1:9999/
    imagePath: d:\upload\

HTML DEMO

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Blog.Csdn.Net/MoshowGame</title>
    <meta charset="utf-8">
</head>

<body>
 <form id="formData" enctype="multipart/form-data" method="post" action="http://localhost:8085/managesys/image/save">
        <input name="checkNum" id="checkNum"  value="21418419" /><br/>
		<input name="facilityTypeNum" id="facilityTypeNum" value="Body001" /><br/>
        <input type="file" name="file" id="file" value="" /><br/>
        <a class="weui-btn-area">
            <input class="weui-btn weui-btn_primary" type="submit" value="UPLOAD"/>
        </a>

    </form>
	 <form id="downData" method="post" action="http://localhost:8085/managesys/image/download">
	<a class="weui-btn-area" onclick="download()">
	<input name="fileName" id="fileName"  value="21418419BODY001-1553004391258.doc" /><br/>
            <input class="weui-btn weui-btn_primary" type="submit" value="DOWNLOAD"/>
        </a>
	</form>	
		
</body>