该函数生成跟php和mysql一致的md5字符串。
public static String md5(String input) throws NoSuchAlgorithmException {
String result = input;
if(input != null) {
MessageDigest md = MessageDigest.getInstance("MD5"); //or "SHA-1"
md.update(input.getBytes());
BigInteger hash = new BigInteger(1, md.digest());
result = hash.toString(16);
while(result.length() < 32) { //40 for SHA-1
result = "0" + result;
}
}
return result;
}