java獲取檔案建立時間
阿新 • • 發佈:2019-02-05
方案一:
private static Date getCreateTime(String fullFileName){ String str = null; try { Process p = Runtime.getRuntime().exec("cmd /C dir \""+fullFileName+"\" /tc"); InputStream is = p.getInputStream(); BufferedReader br = new BufferedReader(new InputStreamReader(is)); int i = 0; while ((str = br.readLine()) != null) { i++; if (i == 6) { SimpleDateFormat sdf = new SimpleDateFormat(osDatetimeFormat); Date d = sdf.parse(str.substring(0, 17)); return d; } } } catch (Exception e) { log.error(str+","+fullFileName+","+e.getMessage(), e); } Calendar cal = Calendar.getInstance(); cal.set(1970, 0, 1, 0, 0, 0); return cal.getTime(); }
本方案呼叫dos命令來獲取檔案的建立時間,是網上大多數人採用的方案,但是該方案存在效能問題。在本人的實際應用中存獲取10萬個檔案的建立時間,花費1個小時。
方案二:
該方案經過測試獲取10萬個檔案的建立時間花費的時間為秒級。推薦使用。但該方案中的BasicFileAttributeView類只存java7以上版本。private static Date getCreateTime2(String fullFileName){ Path path=Paths.get(fullFileName); BasicFileAttributeView basicview=Files.getFileAttributeView(path, BasicFileAttributeView.class,LinkOption.NOFOLLOW_LINKS ); BasicFileAttributes attr; try { attr = basicview.readAttributes(); Date createDate = new Date(attr.creationTime().toMillis()); return createDate; } catch (Exception e) { e.printStackTrace(); } Calendar cal = Calendar.getInstance(); cal.set(1970, 0, 1, 0, 0, 0); return cal.getTime(); }