SpringBoot之文件上传与下载

àì夳堔傛蜴生んèń 2022-03-02 07:14 345阅读 0赞

## 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。  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly96aGVuZ2thaS5ibG9nLmNzZG4ubmV0_size_16_color_FFFFFF_t_70]

## 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="\21418419\BODY001-1553004391258.doc" /><br/>
                <input class="weui-btn weui-btn_primary" type="submit" value="DOWNLOAD"/>
            </a>
    	</form>	
    		
    </body>

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