md5加密，jdk7 与jdk8对含有中文的明文加密注意

private static final String ALGORITHM_MD5 = "MD5";

/**
* Encrypt the password with MD5
*
* @param pass
*            the password to encryption
* @return encryption string
*/
public static String getPassMD5(String pass) {
String keys = null;
try {
MessageDigest md = MessageDigest.getInstance(ALGORITHM_MD5);
if (pass == null) {
pass = "";
}
byte[] bPass = pass.getBytes("UTF-8");
// byte[] bPass = pass.getBytes();  j7 默认编码是u8   而j8不是，所以这个时候，中文加密有问题，j7与j8加密出来的密文不想等，J7是对的
System.out.println(Arrays.toString(bPass));
md.update(bPass);
// keys = new String(md.digest(), "GBK");
keys = bytesToHexString(md.digest());
} catch (Exception aex) {
aex.printStackTrace();
}
return keys;
}

/**
* 将beye[]转换为十六进制字符串
*
* @param bArray
* @return
*/
public static final String bytesToHexString(byte[] bArray) {
System.out.println(Arrays.toString(bArray));
StringBuffer sb = new StringBuffer(bArray.length);
String sTemp;
for (int i = 0; i < bArray.length; i++) {
sTemp = Integer.toHexString(0xFF & bArray[i]);
if (sTemp.length() < 2) {
sb.append(0);
}
sb.append(sTemp.toUpperCase());
}
return sb.toString().toLowerCase();
}