java根据文件流判断文件类型(后缀名)

java根据文件流判断文件类型(后缀名)

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:\\相册\\微信图片\\03.jpg");
        byte[] b = new byte[3];
        is.read(b, 0, b.length);
        String xxx = bytesToHexString(b);
        xxx = xxx.toUpperCase();
        System.out.println("头文件是:" + xxx);
        String ooo = TypeDict.checkType(xxx);
        System.out.println("后缀名是:" + ooo);

    }
    

}
public class TypeDict {
/**
 常用文件的文件头如下:(以前六位为准)
JPEG (jpg),文件头:FFD8FF 
PNG (png),文件头:89504E47 
GIF (gif),文件头:47494638 
TIFF (tif),文件头:49492A00 
Windows Bitmap (bmp),文件头:424D 
CAD (dwg),文件头:41433130 
Adobe Photoshop (psd),文件头:38425053 
Rich Text Format (rtf),文件头:7B5C727466 
XML (xml),文件头:3C3F786D6C 
HTML (html),文件头:68746D6C3E 
Email [thorough only] (eml),文件头:44656C69766572792D646174653A 
Outlook Express (dbx),文件头:CFAD12FEC5FD746F 
Outlook (pst),文件头:2142444E 
MS Word/Excel (xls.or.doc),文件头:D0CF11E0 
MS Access (mdb),文件头:5374616E64617264204A 
WordPerfect (wpd),文件头:FF575043 
Postscript (eps.or.ps),文件头:252150532D41646F6265 
Adobe Acrobat (pdf),文件头:255044462D312E 
Quicken (qdf),文件头:AC9EBD8F 
Windows Password (pwl),文件头:E3828596 
ZIP Archive (zip),文件头:504B0304 
RAR Archive (rar),文件头:52617221 
Wave (wav),文件头:57415645 
AVI (avi),文件头:41564920 
Real Audio (ram),文件头:2E7261FD 
Real Media (rm),文件头:2E524D46 
MPEG (mpg),文件头:000001BA 
MPEG (mpg),文件头:000001B3 
Quicktime (mov),文件头:6D6F6F76 
Windows Media (asf),文件头:3026B2758E66CF11 
MIDI (mid),文件头:4D546864 
*/
    public static String checkType(String xxxx) {
        
        switch (xxxx) {
        case "FFD8FF": return "jpg";
        case "89504E": return "png";
        case "474946": return "jif";

        default: return "0000";
        }
    }

}

 

posted @ 2017-07-04 17:56 路迢迢 阅读( ...) 评论( ...) 编辑 收藏

你可能感兴趣的:(java根据文件流判断文件类型(后缀名))