java上传文件以流方式判断类型

public enum FileType {
/**
* JEPG.
*/
JPEG("FFD8FF"),

/**
* PNG.
*/
PNG("89504E47"),

/**
* GIF.
*/
GIF("47494638"),

/**
* TIFF.
*/
TIFF("49492A00"),

/**
* Windows Bitmap.
*/
BMP("424D"),

/**
* CAD.
*/
DWG("41433130"),

/**
* Adobe Photoshop.
*/
PSD("38425053"),

/**
* Rich Text Format.
*/
RTF("7B5C727466"),

/**
* XML.
*/
XML("3C3F786D6C"),

/**
* HTML.
*/
HTML("68746D6C3E"),
/**
* CSS.
*/
CSS("48544D4C207B0D0A0942"),
/**
* JS.
*/
JS("696B2E71623D696B2E71"),
/**
* Email [thorough only].
*/
EML("44656C69766572792D646174653A"),

/**
* Outlook Express.
*/
DBX("CFAD12FEC5FD746F"),

/**
* Outlook (pst).
*/
PST("2142444E"),

/**
* MS Word/Excel.
*/
XLS_DOC("D0CF11E0"), XLSX_DOCX("504B030414000600080000002100"),
/**
* Visio
*/
VSD("d0cf11e0a1b11ae10000"),
/**
* MS Access.
*/
MDB("5374616E64617264204A"),
/**
* WPS文字wps、表格et、演示dps都是一样的
*/
WPS("d0cf11e0a1b11ae10000"),
/**
* torrent
*/
TORRENT("6431303A637265617465"),
/**
* WordPerfect.
*/
WPD("FF575043"),

/**
* Postscript.
*/
EPS("252150532D41646F6265"),

/**
* Adobe Acrobat.
*/
PDF("255044462D312E"),

/**
* Quicken.
*/
QDF("AC9EBD8F"),

/**
* Windows Password.
*/
PWL("E3828596"),

/**
* ZIP Archive.
*/
ZIP("504B0304"),

/**
* RAR Archive.
*/
RAR("52617221"),
/**
* JSP Archive.
*/
JSP("3C2540207061676520"),
/**
* JAVA Archive.
*/
JAVA("7061636B61676520"),
/**
* CLASS Archive.
*/
CLASS("CAFEBABE0000002E00"),
/**
* JAR Archive.
*/
JAR("504B03040A000000"),
/**
* MF Archive.
*/
MF("4D616E69666573742D56"),
/**
*EXE Archive.
*/
EXE("4D5A9000030000000400"),
/**
*CHM Archive.
*/
CHM("49545346030000006000"),
/*
* INI("235468697320636F6E66"), SQL("494E5345525420494E54"), BAT(
* "406563686F206f66660D"), GZ("1F8B0800000000000000"), PROPERTIES(
* "6C6F67346A2E726F6F74"), MXP(
* "04000000010000001300"),
*/
/**
* Wave.
*/
WAV("57415645"),

/**
* AVI.
*/
AVI("41564920"),

/**
* Real Audio.
*/
RAM("2E7261FD"),

/**
* Real Media.
*/
RM("2E524D46"),

/**
* MPEG (mpg).
*/
MPG("000001BA"),

/**
* Quicktime.
*/
MOV("6D6F6F76"),

/**
* Windows Media.
*/
ASF("3026B2758E66CF11"),

/**
* MIDI.
*/
MID("4D546864"),
/**
* MP4.
*/
MP4("00000020667479706d70"),
/**
* MP3.
*/
MP3("49443303000000002176"),
/**
* FLV.
*/
FLV("464C5601050000000900");
private String value = "";

/**
* Constructor.
*
* @param type
*/
private FileType(String value) {
this.value = value;
}

public String getValue() {
return value;
}

public void setValue(String value) {
this.value = value;
}

}

public final class FileTypeJudge {
/** * Constructor */
private FileTypeJudge() {}
/** * 将文件头转换成16进制字符串 * * @param 原生byte * @return 16进制字符串 */
private 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();
}
/** * 得到文件头 * * @param filePath * 文件路径 * @return 文件头 * @throws IOException */
private static String getFileContent(String filePath) throws IOException {
byte[] b = new byte[28];
InputStream inputStream = null;
try {
inputStream = new FileInputStream(filePath);
inputStream.read(b, 0, 28);
} catch (IOException e) {
e.printStackTrace();
throw e;}
finally {if (inputStream != null)
{
try {inputStream.close();}
catch (IOException e)
{e.printStackTrace();throw e;}}}
return bytesToHexString(b);}
/** * 判断文件类型 * * @param filePath * 文件路径 * @return 文件类型 */
public static FileType getType(String filePath) throws IOException {
String fileHead = getFileContent(filePath);
if (fileHead == null || fileHead.length() == 0) {
return null;}fileHead = fileHead.toUpperCase();
FileType[] fileTypes = FileType.values();
for (FileType type : fileTypes) {
if (fileHead.startsWith(type.getValue())) {
return type;}}return null;}
public static void main(String args[]) throws Exception {
System.out.println(FileTypeJudge.getType("d:\\FileMonitor.java"));
}
}