Java多种文件上传方式总结

我会带着你远行 2022-11-28 13:55 176阅读 0赞

## 请求类型 ##

![在这里插入图片描述][20200818114200823.png_pic_center]

## 单文件上传 ##

![在这里插入图片描述][2020081811425281.png_pic_center]

//上传单个文件
        @ResponseBody
        @RequestMapping(value = "uploadfile", produces = "multipart/form-data;charset=UTF-8")
        public String uploadfiles(HttpServletRequest request){ 
            CommonsMultipartResolver multipartResolver = new CommonsMultipartResolver(request.getSession().getServletContext());
            if (multipartResolver.isMultipart(request)) { 
                DefaultMultipartHttpServletRequest multipartRequest = (DefaultMultipartHttpServletRequest) request;
                MultipartFile multipartFile = multipartRequest.getFile("file");
                if (multipartFile == null) { 
                    System.out.println("multipartFile == null");
                }
                String filename = multipartRequest.getFile("file").getOriginalFilename();
    
                String tmpFile = request.getSession().getServletContext().getRealPath("/") + UUID.randomUUID().toString().replace("-", "") + ".apk";
                File targetFile = new File(tmpFile);
                AppEntity appEntity = new AppEntity();
                if (null != multipartFile) { 
                    //保存文件
                    try { 
                        multipartFile.transferTo(targetFile);
                    } catch (IllegalStateException e) { 
                        logger.error("multipartFile.transferTo, IllegalStateException", e);
                    } catch (IOException e) { 
                        logger.error("multipartFile.transferTo, IOException", e);
                    }
                }
            }
    
            return "";
        }

## 多文件上传 ##

### 多文件单字段上传 ###

![在这里插入图片描述][20200818114227393.png_pic_center]

@ResponseBody
        @RequestMapping(value = "uploadfiles", produces = "multipart/form-data;charset=UTF-8")
        public String uploadfile(MultipartHttpServletRequest request){ 
            CommonsMultipartResolver multipartResolver = new CommonsMultipartResolver(request.getSession().getServletContext());
            if (multipartResolver.isMultipart(request)) { 
                //上传多个文件，一个字段中包含多个文件
                String projectPath = request.getSession().getServletContext().getRealPath("/");
                MultiValueMap<String, MultipartFile> multiFileMap = request.getMultiFileMap();
                List<MultipartFile> fileSet = new LinkedList<>();
                for(Map.Entry<String, List<MultipartFile>> temp : multiFileMap.entrySet()){ 
                    fileSet = temp.getValue();
                }
    
                for(MultipartFile temp : fileSet){ 
                    File file2 = new File(projectPath+temp.getOriginalFilename());
                    try { 
                        temp.transferTo(file2);
                    } catch (IOException e) { 
                        e.printStackTrace();
                    }
                }
            }
    
            return "";
        }

### 多文件多字段上传 ###

![在这里插入图片描述][20200818114336100.png_pic_center]

@ResponseBody
        @RequestMapping(value = "uploadfiles", produces = "multipart/form-data;charset=UTF-8")
        public String uploadfile(MultipartHttpServletRequest request){ 
            CommonsMultipartResolver multipartResolver = new CommonsMultipartResolver(request.getSession().getServletContext());
            if (multipartResolver.isMultipart(request)) { 
                //上传多个文件，每个字段一个文件
                Iterator<String> fileNames = request.getFileNames();
                while (fileNames.hasNext()){ 
                    // 取得上传文件
                    String uploadName = fileNames.next();
                    MultipartFile file = request.getFile(uploadName);
                    if (file != null) { 
                        String projectPath = request.getSession().getServletContext().getRealPath("/");
                        String originalFilename = file.getOriginalFilename();
                        String tmpFile = projectPath + System.currentTimeMillis() + "_" + originalFilename;
                        File targetFile = new File(tmpFile);
                        try { 
                            file.transferTo(targetFile);
                        } catch (IOException e) { 
                            e.printStackTrace();
                        }
                    }
                }
            }
    
            return "";
        }

### 如果上面方法不行,看下面 ###

@PostMapping(value = "test", produces = "multipart/form-data;charset=UTF-8")
    public void UploadFiles(HttpServletRequest request) throws IOException { 
        //如果请求中包含文件
        if(ServletFileUpload.isMultipartContent(request)){ 
            // 创建一个通用的多部分解析器
            MultipartHttpServletRequest multipartRequest = (MultipartHttpServletRequest) request;
            List<MultipartFile> files = multipartRequest.getFiles("file");
            File targetFile;
            for (MultipartFile file : files){ 
                //保存文件到本地
                String projectPath = request.getSession().getServletContext().getRealPath("/");
                projectPath = projectPath + System.currentTimeMillis() + "_" + new Random().nextInt(100);
                File dir = new File(projectPath);
                if (!dir.exists()){ 
                    dir.mkdir();
                }
                String originalFilename = file.getOriginalFilename();
                String tmpFile = projectPath + File.separator + originalFilename;
                targetFile = new File(tmpFile);
                file.transferTo(targetFile);
                //将文件保存到本地并记录信息
                //...
            }
        }
    }

还有一种方法，函数入参直接接受文件，例如：

//单文件
    public String UploadFiles(@RequestParam("file") MultipartFile file){ 
    }
    
    //多文件
    public String UploadFiles(@RequestParam("file") List<MultipartFile> files){ 
    }

over！

[20200818114200823.png_pic_center]: /images/20221124/40dd8e2d409841f3bb2872a13f60878c.png
[2020081811425281.png_pic_center]: /images/20221124/e0b00bacde914f9faf033d30fc91957f.png
[20200818114227393.png_pic_center]: /images/20221124/bfc0b7f6fdfa4dd9b4d100e5d95148c2.png
[20200818114336100.png_pic_center]: /images/20221124/d6e23daca37c4fa585687e3e4da05e01.png