example-v2/concurrent/src/main/java/cn/enjoyedu/ch8b/assist/EncryptUtils.java
public static String to_MD5(String s) {
        char hexDigits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
                'a', 'b', 'c', 'd', 'e', 'f' };
        try {
            byte[] strTemp = s.getBytes();
            MessageDigest mdTemp = MessageDigest.getInstance("MD5");
            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);
        } catch (Exception e) {
            return null;
        }
    }
/**
     * @param s
     *       the string want to encode
     * @return
     *       the encoded String
     */
@param s
the string want to encode
@return
the encoded String
@param s the string want to encode @return the encoded String
public static String to_MD5(String s) {
        char hexDigits[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
                'a', 'b', 'c', 'd', 'e', 'f' };
        try {
            byte[] strTemp = s.getBytes();
            MessageDigest mdTemp = MessageDigest.getInstance("MD5");
            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);
        } catch (Exception e) {
            return null;
        }
    }
public static String to_MD5 ( String s ) { char hexDigits [ ] = { '0' , '1' , '2' , '3' , '4' , '5' , '6' , '7' , '8' , '9' , 'a' , 'b' , 'c' , 'd' , 'e' , 'f' } ; try { byte [ ] strTemp = s . getBytes ( ) ; MessageDigest mdTemp = MessageDigest . getInstance ( "MD5" ) ; 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 ) ; } catch ( Exception e ) { return null ; } }
@param s
       the string want to encode
 @return
       the encoded String
@param s the string want to encode @return the encoded String