import java.io.FileInputStream; public class FileType{ 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); } return stringBuilder.toString(); } /** * @param args */ public static void main(String[] args) throws Exception { FileInputStream is = new FileInputStream("F:\\相冊\\微信圖片\\03.jpg"); byte[] b = new byte[3]; is.read(b, 0, b.length); String xxx = bytesToHexString(b); xxx = xxx.toUpperCase(); System.out.println("頭文件是:" + xxx); String ooo = TypeDict.checkType(xxx.substring(0,6)); System.out.println("後綴名是:" + ooo); } }
public class TypeDict { /** 常用文件的文件頭如下:(以前六位爲準) JPEG (jpg),文件頭:FFD8FF PNG (png),文件頭:89504E47 GIF (gif),文件頭:47494638 TIFF (tif),文件頭:49492A00 Windows Bitmap (bmp),文件頭:424D CAD (dwg),文件頭:41433130 Adobe Photoshop (psd),文件頭:38425053 Rich Text Format (rtf),文件頭:7B5C727466 XML (xml),文件頭:3C3F786D6C HTML (html),文件頭:68746D6C3E Email [thorough only] (eml),文件頭:44656C69766572792D646174653A Outlook Express (dbx),文件頭:CFAD12FEC5FD746F Outlook (pst),文件頭:2142444E MS Word/Excel (xls.or.doc),文件頭:D0CF11E0 MS Access (mdb),文件頭:5374616E64617264204A WordPerfect (wpd),文件頭:FF575043 Postscript (eps.or.ps),文件頭:252150532D41646F6265 Adobe Acrobat (pdf),文件頭:255044462D312E Quicken (qdf),文件頭:AC9EBD8F Windows Password (pwl),文件頭:E3828596 ZIP Archive (zip),文件頭:504B0304 RAR Archive (rar),文件頭:52617221 Wave (wav),文件頭:57415645 AVI (avi),文件頭:41564920 Real Audio (ram),文件頭:2E7261FD Real Media (rm),文件頭:2E524D46 MPEG (mpg),文件頭:000001BA MPEG (mpg),文件頭:000001B3 Quicktime (mov),文件頭:6D6F6F76 Windows Media (asf),文件頭:3026B2758E66CF11 MIDI (mid),文件頭:4D546864 */ public static String checkType(String str) {
switch (xxxx) { case "FFD8FF": return "jpg"; case "89504E": return "png"; case "474946": return "jif"; default: return "0000"; } } }