SpringBoot文件上传下载

逃离我推掉我的手 2022-02-13 02:21 388阅读 0赞

## 前言 ##

#### [博主github][github] ####

#### [博主个人博客http://blog.healerjean.com][http_blog.healerjean.com] ####

习惯了使用OSS傻瓜式上传，是不是都快忘记写原生的上传了，今天小米的项目中需要用一下，所以之类简单总结下 吧

<table> 
 <thead> 
  <tr> 
   <th>MultipartFile file 方法名字</th> 
   <th>内容</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>file.getContentType()</td> 
   <td>image/png</td> 
  </tr> 
  <tr> 
   <td>file.getOriginalFilename()</td> 
   <td>AAAA.png</td> 
  </tr> 
  <tr> 
   <td>file.getName()</td> 
   <td>file</td> 
  </tr> 
 </tbody> 
</table>

## 1、上传 ##

#### 1、FileUtils.copyInputStreamToFile ####

File localFile = new File(tempFile,fileName);
    FileUtils.copyInputStreamToFile(file.getInputStream(),localFile);

#### 2、file.transferTo ####

我使用这种方式报错了，没有深入研究，网上说是jar包问题
    
    <dependency>
        	<groupId>commons-fileupload</groupId>
        	<artifactId>commons-fileupload</artifactId>
        	<version>1.3.1</version>
    </dependency>
    
    
    
    File localFile = new File(tempFile,fileName);
    file.transferTo(localFile);

#### 3、正常读取 ####

byte[] bytes = file.getBytes();
     
    File localFile = new File(tempFile,fileName);
    
    BufferedOutputStream stream = new BufferedOutputStream(
        new FileOutputStream(localFile));
    
    stream.write(bytes);
    
    
    
    
    BufferedOutputStream out = new BufferedOutputStream(
        new FileOutputStream(localFile));
    in = file.getInputStream();
    int num = 0;
    byte[] b = new byte[1024];
    while((num = in.read(b)) != -1) { 
        out.write(b, 0, num);
    }

@Override
        public String upload(MultipartFile file){ 
    
            String name = UUID.randomUUID().toString().replaceAll("-", "");
            LocalDateTime dateTime = LocalDateTime.now();
            DateTimeFormatter df = DateTimeFormatter.ofPattern("yyyy-MM-dd");
            String localTime = df.format(dateTime);
    
            //文件存储最终目录
            File tempFile = new File("/User/healerjean/Desktop"+localTime);
            if(!tempFile.exists()){ 
                tempFile.mkdirs();
            }
            
            String fileName = file.getOriginalFilename();
            fileName = name+fileName.substring(fileName.lastIndexOf(".") );
            
            File localFile = new File(tempFile,fileName);
            try { 
                FileUtils.copyInputStreamToFile(file.getInputStream(),localFile);
                
            
                //2、 file.transferTo(localFile);
                
            } catch (IOException e) { 
                throw new RuntimeException(e.getMessage(),e);
            }
          return fileName;
        }

## 2、下载 ##

@GetMapping("/{id}")
    public void downLoad(HttpServletResponse response,String folder) { 
        try { 
            InputStream inputStream = new FileInputStream(new File(folder));
            OutputStream outputStream = response.getOutputStream();
    
            response.setContentType("application/x-download");
            response.setHeader("Content-Disposition", "attachment;filename=test.txt");
    
            IOUtils.copy(inputStream, outputStream);
            outputStream.flush();
        } catch (Exception e) { 
    
        }
    }

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[github]: https://github.com/HealerJean
[http_blog.healerjean.com]: http://HealerJean.github.io
[ContactAuthor]: /images/20220213/b5327f060c1f41eebf63081ffce5f63e.png