2021-02-02

判断上传图片的类型。这里只判断了图片的类型。根据需求自己修改，

 // @Jurisdiction
   // @RootAndClass("ImageUp")
    @PostMapping("/ImageUp")
    public Object ImageUp(@RequestParam("Image") MultipartFile me,HttpServletRequest request) {

        String path =request.getSession().getServletContext().getRealPath("");
        System.out.println(path);
        if(me.isEmpty()){
              return ResponseDataUtil.buildError("请上传图片");
        }else {
            try {
                FileInputStream is = (FileInputStream) me.getInputStream();
                if(!ImageController.IsBooleanImage(is)){
                    System.out.println("该文件不符合图片类型");
                }
              
            }catch (Exception e){
                System.out.println(e);
                return  e;
            }
        }

        return ResponseDataUtil.buildError("上传成功");
    }

 //判断是否是图片
    public static boolean IsBooleanImage(FileInputStream is) throws IOException {

       // FileInputStream is = new FileInputStream("F:\\aaa.jpg");
        byte[] b = new byte[3];
        is.read(b, 0, b.length);
        String photo = bytesToHexString(b);
        System.out.println("photo :"+photo);
        boolean ooo = ImageController.checkType(photo);
        System.out.println("后缀名是：" + ooo);
        return  ooo;
    }

    public static String bytesToHexString(byte[] src) {
        StringBuilder stringBuilder = new StringBuilder();
        if (src == null || src.length <= 0) {
            return null;
        }
        for (int i = 0; i < src.length; i++) {
            int v = src[i] & 0xFF;
            String hv = Integer.toHexString(v);
            if (hv.length() < 2) {
                stringBuilder.append(0);
            }
            stringBuilder.append(hv.toUpperCase());  //小写转大写
        }
        return stringBuilder.toString();
    }

    public static boolean checkType(String fileType) {

        switch (fileType) {
            case "FFD8FF": return true;  //jpg
            case "89504E": return true;  //png
            case "474946": return true;  //jif
            default: return false;
        }
    }