from:
http://www.iteye.com/topic/1127319 MD5 nio的简单版，看你们老是怀疑java慢 C++ MD5工具验证结果： File: K:\Games\World of Warcraft\Data\common.MPQ Size: 2226587191 bytes Modified: 2008年11月19日 星期三, 12:57:24 MD5: CD9F9C5523F3BA3866B81CCC74ED6476 java运行结果，毫秒 耗时：12672,cd9f9c5523f3ba3866b81ccc74ed6476 String hashType = "MD5";
FileInputStream fStream =
null;
try {
MessageDigest md5 = MessageDigest.getInstance(hashType);
fStream =
new FileInputStream(
//"K:\\Games\\World of Warcraft\\Scan.dll");
//"K:\\Games\\World of Warcraft\\Data\\patch-3.MPQ");
"K:\\Games\\World of Warcraft\\Data\\common.MPQ");
FileChannel fChannel = fStream.getChannel();
ByteBuffer buffer = ByteBuffer.allocate(8*1024);
long s = System.currentTimeMillis();
for (
int count = fChannel.read( buffer ); count !=-1 ; count = fChannel.read( buffer )
) {
buffer.flip();
md5.update( buffer );
if( !buffer.hasRemaining() ){
//System.out.println("count:"+count);
buffer.clear();
}
}
s = System.currentTimeMillis() - s;
System.out.println( "耗时："+s+","+getString( md5.digest() ) );
}
catch (NoSuchAlgorithmException e) {
e.printStackTrace();
}
catch (FileNotFoundException e) {
e.printStackTrace();
}
catch (IOException e) {
e.printStackTrace();
}
finally{
try {
if( fStream!=
null )
fStream.close();
}
catch (IOException e) {
e.printStackTrace();
}
}