package com.nfschina.utils.file;
import java.io.File;
import java.io.FileInputStream;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Map.Entry;
import com.nfschina.utils.BaseException;
/***********************************************************************
*
* Description: 主要用于判断文件的类型
*
***********************************************************************/
public class FileTools {
public final static Map FILE_TYPE_MAP = new HashMap();
/*-----------------------------目前可以识别的类型----------------------------*/
private static void getAllFileType()
{
FILE_TYPE_MAP.put("jpg", "FFD8FF"); //JPEG
FILE_TYPE_MAP.put("png", "89504E47"); //PNG
FILE_TYPE_MAP.put("gif", "47494638"); //GIF
FILE_TYPE_MAP.put("tif", "49492A00"); //TIFF
FILE_TYPE_MAP.put("bmp", "424D"); //Windows Bitmap
FILE_TYPE_MAP.put("dwg", "41433130"); //CAD
FILE_TYPE_MAP.put("html", "68746D6C3E"); //HTML
FILE_TYPE_MAP.put("rtf", "7B5C727466"); //Rich Text Format
FILE_TYPE_MAP.put("xml", "3C3F786D6C");
FILE_TYPE_MAP.put("zip", "504B0304");
FILE_TYPE_MAP.put("rar", "52617221");
FILE_TYPE_MAP.put("psd", "38425053"); //PhotoShop
FILE_TYPE_MAP.put("eml", "44656C69766572792D646174653A"); //Email [thorough only]
FILE_TYPE_MAP.put("dbx", "CFAD12FEC5FD746F"); //Outlook Express
FILE_TYPE_MAP.put("pst", "2142444E"); //Outlook
FILE_TYPE_MAP.put("office", "D0CF11E0"); //office类型，包括doc、xls和ppt
FILE_TYPE_MAP.put("mdb", "000100005374616E64617264204A"); //MS Access
FILE_TYPE_MAP.put("wpd", "FF575043"); //WordPerfect
FILE_TYPE_MAP.put("eps", "252150532D41646F6265");
FILE_TYPE_MAP.put("ps", "252150532D41646F6265");
FILE_TYPE_MAP.put("pdf", "255044462D312E"); //Adobe Acrobat
FILE_TYPE_MAP.put("qdf", "AC9EBD8F"); //Quicken
FILE_TYPE_MAP.put("pwl", "E3828596"); //Windows Password
FILE_TYPE_MAP.put("wav", "57415645"); //Wave
FILE_TYPE_MAP.put("avi", "41564920");
FILE_TYPE_MAP.put("ram", "2E7261FD"); //Real Audio
FILE_TYPE_MAP.put("rm", "2E524D46"); //Real Media
FILE_TYPE_MAP.put("mpg", "000001BA"); //
FILE_TYPE_MAP.put("mov", "6D6F6F76"); //Quicktime
FILE_TYPE_MAP.put("asf", "3026B2758E66CF11"); //Windows Media
FILE_TYPE_MAP.put("mid", "4D546864"); //MIDI (mid)
}
/**
* 通过读取文件头部获得文件类型
* @param file
* @return 文件类型
* @throws BaseException
*/
public static String getFileType(File file) throws BaseException{
getAllFileType();
String fileExtendName = null;
FileInputStream is;
try {
is = new FileInputStream(file);
byte[] b = new byte[16];
is.read(b,0, b.length);
String filetypeHex = String.valueOf(bytesToHexString(b));
Iterator> entryiterator = FILE_TYPE_MAP.entrySet().iterator();
while (entryiterator.hasNext()) {
Entry entry = entryiterator.next();
String fileTypeHexValue = entry.getValue();
if (filetypeHex.toUpperCase().startsWith(fileTypeHexValue)) {
fileExtendName = entry.getKey();
if(fileExtendName.equals("office")) {
fileExtendName = getOfficeFileType(is);
}
is.close();
break;
}
}
// 如果不是上述类型，则判断扩展名
if(fileExtendName == null)
{
String fileName = file.getName();
// 如果无扩展名，则直接返回空串
if(-1 == fileName.indexOf("."))
{
return "";
}
// 如果有扩展名，则返回扩展名
return fileName.substring(fileName.indexOf(".") + 1);
}
is.close();
return fileExtendName;
} catch (Exception exception) {
throw new BaseException(exception.getMessage(), exception);
}
}
/**
* 判断office文件的具体类型
* @param fileInputStream
* @return office文件具体类型
* @throws BaseException
*/
private static String getOfficeFileType(FileInputStream fileInputStream) throws BaseException{
String officeFileType = "doc";
byte[] b = new byte[512];
try {
fileInputStream.read(b, 0, b.length);
String filetypeHex = String.valueOf(bytesToHexString(b));
String flagString = filetypeHex.substring(992, filetypeHex.length());
if(flagString.toLowerCase().startsWith("eca5c")){
officeFileType = "doc";
} else if(flagString.toLowerCase().startsWith("fdffffff09")){
officeFileType = "xls";
} else if(flagString.toLowerCase().startsWith("09081000000")){
officeFileType = "xls";
} else {
officeFileType = "ppt";
}
return officeFileType;
} catch (Exception exception) {
throw new BaseException(exception.getMessage(), exception);
}
}
/**
* 获得文件头部字符串
* @param src
* @return
*/
private static String bytesToHexString(byte[] src){
StringBuilder stringBuilder = new StringBuilder();
if (src == null || src.length <= 0) {
return null;
}
for (int i = 0; i 
int v = src[i] & 0xFF;
String hv = Integer.toHexString(v);
if (hv.length() 
stringBuilder.append(0);
}
stringBuilder.append(hv);
}
return stringBuilder.toString();
}
public static void main(String[] args)
{
File file = new File("E:/新闻公告.pdm");
FileInputStream is;
try{
is = new FileInputStream(file);
byte[] b = new byte[16];
is.read(b,0, b.length);
//            String filetypeHex = String.valueOf(bytesToHexString(b));
String fileName = file.getName();
System.out.println(fileName.substring(fileName.indexOf(".") + 1));
}catch(Exception e)
{
e.printStackTrace();
}
}