adolfjap

java md5 返回值和php md5一样

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

import java.nio.MappedByteBuffer;

import java.nio.channels.FileChannel;

import java.security.MessageDigest;

import java.security.NoSuchAlgorithmException;

 

 

public class MD5FileUtil {

protected static char hexDigits[] = { '0', '1', '2', '3', '4', '5', '6',

'7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };

protected static MessageDigest messagedigest = null;

static {

try {

messagedigest = MessageDigest.getInstance("MD5");

} catch (NoSuchAlgorithmException e) {

}

}

 

public static String getFileMD5String(File file) throws IOException

{

FileInputStream in = new FileInputStream(file);

FileChannel ch = in.getChannel();

MappedByteBuffer byteBuffer = ch.map(FileChannel.MapMode.READ_ONLY, 0,

file.length());

messagedigest.update(byteBuffer);

in.close();

return bufferToHex(messagedigest.digest());

}

 

public static String getMD5String(String s) {

return getMD5String(s.getBytes());

}

 

public static String getMD5String(byte[] bytes) {

messagedigest.update(bytes);

return bufferToHex(messagedigest.digest());

}

 

private static String bufferToHex(byte bytes[]) {

return bufferToHex(bytes, 0, bytes.length);

}

 

private static String bufferToHex(byte bytes[], int m, int n) {

StringBuffer stringbuffer = new StringBuffer(2 * n);

int k = m + n;

for (int l = m; l < k; l++) {

appendHexPair(bytes[l], stringbuffer);

}

return stringbuffer.toString();

}

 

private static void appendHexPair(byte bt, StringBuffer stringbuffer) {

char c0 = hexDigits[(bt & 0xf0) >> 4];

char c1 = hexDigits[bt & 0xf];

stringbuffer.append(c0);

stringbuffer.append(c1);

}

 

public static boolean checkPassword(String password, String md5PwdStr) {

String s = getMD5String(password);

return s.equals(md5PwdStr);

}

 

public static void main(String[] args) throws IOException {

long begin = System.currentTimeMillis();

 

File file= new File("/tmp/test.txt");

String md5 = getFileMD5String(file);

 

long end = System.currentTimeMillis();

System.out.println("md5:" + md5);

 

}

 

}