import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; public class Strings { // MD5演算 public final static String MD5(String s) { char hexDigits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' }; byte[] strTemp = s.getBytes(); MessageDigest mdTemp = null; try { mdTemp = MessageDigest.getInstance("MD5"); } catch (NoSuchAlgorithmException e) { e.printStackTrace(); } mdTemp.update(strTemp); byte[] md = mdTemp.digest(); int j = md.length; char str[] = new char[j * 2]; int k = 0; for (int i = 0; i < j; i++) { byte byte0 = md[i]; str[k++] = hexDigits[byte0 >>> 4 & 0xf]; str[k++] = hexDigits[byte0 & 0xf]; } return new String(str); } }