package cn.me.fdfs.util;
import java.io.*;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
/**
* @author zhanghf
*
*/
public class DigestUtil
{
private static char[] base64EncodeChars = new char[] {
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
'w', 'x', 'y', 'z', '0', '1', '2', '3',
'4', '5', '6', '7', '8', '9', '+', '/' };
private static byte[] base64DecodeChars = new byte[] {
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1,
-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1 };
static char hexdigits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8',
'9', 'a', 'b', 'c', 'd', 'e', 'f' };
public static String getMd5Digest(String cleanText)
{
MessageDigest digest = null;
try
{
digest = MessageDigest.getInstance("MD5");
}
catch (NoSuchAlgorithmException e)
{
// failed to load the MD5 algorithm
return null;
}
byte[] hashBytes = null;
try
{
digest.update( cleanText.getBytes());
hashBytes = digest.digest();
}
catch (Exception e)
{
// failed to compute hash
return null;
}
String result = encodeHex(hashBytes);
return result;
}
public static String getMd5DigestFileByReadFile(String filePath)
{
MessageDigest digest = null;
String str = "", data = "";
try
{
digest = MessageDigest.getInstance("MD5");
}
catch (NoSuchAlgorithmException e)
{
// failed to load the MD5 algorithm
return null;
}
byte[] hashBytes = null;
try
{
BufferedReader br = new BufferedReader(new InputStreamReader(new FileInputStream(filePath)));
while((data = br.readLine())!=null)
{
str = str + data;
}
digest.update( str.getBytes());
hashBytes = digest.digest();
}
catch (Exception e)
{
// failed to compute hash
return null;
}
String result = encodeHex(hashBytes);
return result;
}
/**
* 对文件全文生成MD5摘要
*
* @param file
* 要加密的文件
* @return MD5摘要码
*/
public static String getMd5DigestFile(String filePath) {
FileInputStream fis = null;
try {
MessageDigest md = MessageDigest.getInstance("MD5");
fis = new FileInputStream(new File(filePath));
byte[] buffer = new byte[2048];
int length = -1;
long s = System.currentTimeMillis();
while ((length = fis.read(buffer)) != -1) {
md.update(buffer, 0, length);
}
byte[] b = md.digest();
return byteToHexString(b);
// 16位加密
// return buf.toString().substring(8, 24);
} catch (Exception ex) {
ex.printStackTrace();
return null;
} finally {
try {
fis.close();
} catch (IOException ex) {
ex.printStackTrace();
}
}
}
/**
* 把byte[]数组转换成十六进制字符串表示形式
* @param tmp 要转换的byte[]
* @return 十六进制字符串表示形式
*/
private static String byteToHexString(byte[] tmp) {
String s;
// 用字节表示就是 16 个字节
char str[] = new char[16 * 2]; // 每个字节用 16 进制表示的话，使用两个字符，
// 所以表示成 16 进制需要 32 个字符
int k = 0; // 表示转换结果中对应的字符位置
for (int i = 0; i < 16; i++) { // 从第一个字节开始，对 MD5 的每一个字节
// 转换成 16 进制字符的转换
byte byte0 = tmp[i]; // 取第 i 个字节
str[k++] = hexdigits[byte0 >>> 4 & 0xf]; // 取字节中高 4 位的数字转换,
// >>> 为逻辑右移，将符号位一起右移
str[k++] = hexdigits[byte0 & 0xf]; // 取字节中低 4 位的数字转换
}
s = new String(str); // 换后的结果转换为字符串
return s;
}
private static String encodeHex(byte[] bytes)
{
StringBuffer hex = new StringBuffer(bytes.length * 2);
for (int i = 0; i < bytes.length; i++)
{
if (((int) bytes[i] & 0xff) < 0x10)
{
hex.append("0");
}
hex.append(Integer.toString((int) bytes[i] & 0xff, 16));
}
return hex.toString().toUpperCase();
}
//����
public static String encode(byte[] data) {
StringBuffer sb = new StringBuffer();
int len = data.length;
int i = 0;
int b1, b2, b3;
while (i < len) {
b1 = data[i++] & 0xff;
if (i == len)
{
sb.append(base64EncodeChars[b1 >>> 2]);
sb.append(base64EncodeChars[(b1 & 0x3) << 4]);
sb.append("==");
break;
}
b2 = data[i++] & 0xff;
if (i == len)
{
sb.append(base64EncodeChars[b1 >>> 2]);
sb.append(base64EncodeChars[((b1 & 0x03) << 4) | ((b2 & 0xf0) >>> 4)]);
sb.append(base64EncodeChars[(b2 & 0x0f) << 2]);
sb.append("=");
break;
}
b3 = data[i++] & 0xff;
sb.append(base64EncodeChars[b1 >>> 2]);
sb.append(base64EncodeChars[((b1 & 0x03) << 4) | ((b2 & 0xf0) >>> 4)]);
sb.append(base64EncodeChars[((b2 & 0x0f) << 2) | ((b3 & 0xc0) >>> 6)]);
sb.append(base64EncodeChars[b3 & 0x3f]);
}
return sb.toString();
}
//����
public static byte[] decode(String str) throws UnsupportedEncodingException {
StringBuffer sb = new StringBuffer();
byte[] data = str.getBytes("US-ASCII");
int len = data.length;
int i = 0;
int b1, b2, b3, b4;
while (i < len) {
/* b1 */
do {
b1 = base64DecodeChars[data[i++]];
} while (i < len && b1 == -1);
if (b1 == -1) break;
/* b2 */
do {
b2 = base64DecodeChars[data[i++]];
} while (i < len && b2 == -1);
if (b2 == -1) break;
sb.append((char)((b1 << 2) | ((b2 & 0x30) >>> 4)));
/* b3 */
do {
b3 = data[i++];
if (b3 == 61) return sb.toString().getBytes("iso8859-1");
b3 = base64DecodeChars[b3];
} while (i < len && b3 == -1);
if (b3 == -1) break;
sb.append((char)(((b2 & 0x0f) << 4) | ((b3 & 0x3c) >>> 2)));
/* b4 */
do {
b4 = data[i++];
if (b4 == 61) return sb.toString().getBytes("iso8859-1");
b4 = base64DecodeChars[b4];
} while (i < len && b4 == -1);
if (b4 == -1) break;
sb.append((char)(((b3 & 0x03) << 6) | b4));
}
return sb.toString().getBytes("iso8859-1");
}
public static void main(String[] args) {
// TODO Auto-generated method stub
String abc = getMd5DigestFile("d:/1.vx2");
System.out.print(abc);
}
}