記錄檔案預覽另一種方式

1. nginx方式
   location /file/ {
   alias /home/jclazz/80kj/smart-admin/uploadfile/image/;#指定圖片存放路徑
   #access_log /usr/local/websrv/nginx-1.9.4/logs/images.log;#日誌存放路徑
   }

2. 另一種方式

	public ResponseEntity<byte[]> getImg(@PathVariable(name = "fileName") String fileName) {
		log.error("預覽圖片 {}",fileName);
		File file = new File(location + fileName);
		if(!file.exists()){
			return ResponseEntity.notFound().build();
		}
		Optional<MediaType> mediaType = MediaTypeFactory.getMediaType(fileName);
		if(!mediaType.isPresent()){
			return ResponseEntity.badRequest().build();
		}
		byte[] bytes = FileReader.create(file).readBytes();
		return ResponseEntity.ok().contentType(mediaType.get()).body(bytes);
	}