library.java

Java写的含有一个jdbc驱动的小型数据库数据库引擎

    public static String ltrim(String s) {
	if (s == null) {
	    return s;
	}

	int len = s.length(), i = 0;

	while (i < len && s.charAt(i) <= ' ') {
	    i++;
	}

	return i == 0 ? s : s.substring(i);
    }

    /**
     * Method declaration
     *
     *
     * @param s
     * @param i
     *
     * @return
     */
    public static String repeat(String s, int i) {
	if (s == null) {
	    return null;
	}

	StringBuffer b = new StringBuffer();

	while (i-- > 0) {
	    b.append(s);
	}

	return b.toString();
    }

    /**
     * Method declaration
     *
     *
     * @param s
     * @param replace
     * @param with
     *
     * @return
     */
    public static String replace(String s, String replace, String with) {
	if (s == null || replace == null) {
	    return s;
	}

	if (with == null) {
	    with = "";
	}

	StringBuffer b = new StringBuffer();
	int	     start = 0;
	int	     lenreplace = replace.length();

	while (true) {
	    int i = s.indexOf(replace, start);

	    if (i == -1) {
		b.append(s.substring(start));

		break;
	    }

	    b.append(s.substring(start, i - start));
	    b.append(with);

	    start = i + lenreplace;
	}

	return b.toString();
    }

    /**
     * Method declaration
     *
     *
     * @param s
     * @param i
     *
     * @return
     */
    public static String right(String s, int i) {
	if (s == null) {
	    return null;
	}

	i = s.length() - i;

	return s.substring(i < 0 ? 0 : i < s.length() ? i : s.length());
    }

    /**
     * Method declaration
     *
     *
     * @param s
     *
     * @return
     */
    public static String rtrim(String s) {
	if (s == null) {
	    return s;
	}

	int i = s.length() - 1;

	while (i >= 0 && s.charAt(i) <= ' ') {
	    i--;
	}

	return i == s.length() ? s : s.substring(0, i + 1);
    }

    /**
     * Method declaration
     *
     *
     * @param s
     *
     * @return
     */
    public static String soundex(String s) {
	if (s == null) {
	    return s;
	}

	s = s.toUpperCase();

	int  len = s.length();
	char b[] = new char[4];

	b[0] = s.charAt(0);

	int j = 1;

	for (int i = 1; i < len && j < 4; i++) {
	    char c = s.charAt(i);

	    if ("BFPV".indexOf(c) != -1) {
		b[j++] = '1';
	    } else if ("CGJKQSXZ".indexOf(c) != -1) {
		b[j++] = '2';
	    } else if (c == 'D' || c == 'T') {
		b[j++] = '3';
	    } else if (c == 'L') {
		b[j++] = '4';
	    } else if (c == 'M' || c == 'N') {
		b[j++] = '5';
	    } else if (c == 'R') {
		b[j++] = '6';
	    }
	}

	return new String(b, 0, j);
    }

    /**
     * Method declaration
     *
     *
     * @param i
     *
     * @return
     */
    public static String space(int i) {
	if (i < 0) {
	    return null;
	}

	char c[] = new char[i];

	while (i > 0) {
	    c[--i] = ' ';
	}

	return new String(c);
    }

    /**
     * Method declaration
     *
     *
     * @param s
     * @param start
     * @param length
     *
     * @return
     */
    public static String substring(String s, int start, Integer length) {
	if (s == null) {
	    return null;
	}

	int len = s.length();

	start--;
	start = start > len ? len : start;

	if (length == null) {
	    return s.substring(start);
	} else {
	    int l = length.intValue();

	    return s.substring(start, start + l > len ? len : l);
	}
    }

    /**
     * Method declaration
     *
     *
     * @param s
     *
     * @return
     */
    public static String ucase(String s) {
	return s == null ? null : s.toUpperCase();
    }

    // TIME AND DATE

    /**
     * Method declaration
     *
     *
     * @return
     */
    public static java.sql.Date curdate() {
	return new java.sql.Date(System.currentTimeMillis());
    }

    /**
     * Method declaration
     *
     *
     * @return
     */
    public static java.sql.Time curtime() {
	return new java.sql.Time(System.currentTimeMillis());
    }

    /**
     * Method declaration
     *
     *
     * @param d
     *
     * @return
     */
    public static String dayname(java.sql.Date d) {
	SimpleDateFormat f = new SimpleDateFormat("EEEE");

	return f.format(d).toString();
    }

    /**
     * Method declaration
     *
     *
     * @param d
     * @param part
     *
     * @return
     */
    private static int getDateTimePart(java.util.Date d, int part) {
	Calendar c = new GregorianCalendar();

	c.setTime(d);

	return c.get(part);
    }

    /**
     * Method declaration
     *
     *
     * @param t
     * @param part
     *
     * @return
     */
    private static int getTimePart(java.sql.Time t, int part) {
	Calendar c = new GregorianCalendar();

	c.setTime(t);

	return c.get(part);
    }

    /**
     * Method declaration
     *
     *
     * @param d
     *
     * @return
     */
    public static int dayofmonth(java.sql.Date d) {
	return getDateTimePart(d, Calendar.DAY_OF_MONTH);
    }

    /**
     * Method declaration
     *
     *
     * @param d
     *
     * @return
     */
    public static int dayofweek(java.sql.Date d) {
	return getDateTimePart(d, Calendar.DAY_OF_WEEK);
    }

    /**
     * Method declaration
     *
     *
     * @param d
     *
     * @return
     */
    public static int dayofyear(java.sql.Date d) {
	return getDateTimePart(d, Calendar.DAY_OF_YEAR);
    }

    /**
     * Method declaration
     *
     *
     * @param t
     *
     * @return
     */
    public static int hour(java.sql.Time t) {
	return getDateTimePart(t, Calendar.HOUR);
    }

    /**
     * Method declaration
     *
     *
     * @param t
     *
     * @return
     */
    public static int minute(java.sql.Time t) {
	return getDateTimePart(t, Calendar.MINUTE);
    }

    /**
     * Method declaration
     *
     *
     * @param d
     *
     * @return
     */
    public static int month(java.sql.Date d) {
	return getDateTimePart(d, Calendar.MONTH);
    }

    /**
     * Method declaration
     *
     *
     * @param d
     *
     * @return
     */
    public static String monthname(java.sql.Date d) {
	SimpleDateFormat f = new SimpleDateFormat("MMMM");

	return f.format(d).toString();
    }

    /**
     * Method declaration
     *
     *
     * @return
     */
    public static Timestamp now() {
	return new Timestamp(System.currentTimeMillis());
    }

    /**
     * Method declaration
     *
     *
     * @param d
     *
     * @return
     */
    public static int quarter(java.sql.Date d) {
	return (getDateTimePart(d, Calendar.MONTH) / 3) + 1;
    }

    /**
     * Method declaration
     *
     *
     * @param d
     *
     * @return
     */
    public static int second(java.sql.Date d) {
	return getDateTimePart(d, Calendar.SECOND);
    }

    /**
     * Method declaration
     *
     *
     * @param d
     *
     * @return
     */
    public static int week(java.sql.Date d) {
	return getDateTimePart(d, Calendar.WEEK_OF_YEAR);
    }

    /**
     * Method declaration
     *
     *
     * @param d
     *
     * @return
     */
    public static int year(java.sql.Date d) {
	return getDateTimePart(d, Calendar.YEAR);
    }

    // SYSTEM

    /**
     * Method declaration
     *
     *
     * @param conn
     *
     * @return
     *
     * @throws SQLException
     */
    public static String database(Connection conn) throws SQLException {
	Statement stat = conn.createStatement();
	String    s =
	    "SELECT Value FROM SYSTEM_CONNECTIONINFO WHERE KEY='DATABASE'";
	ResultSet r = stat.executeQuery(s);

	r.next();

	return r.getString(1);
    }

    /**
     * Method declaration
     *
     *
     * @param conn
     *
     * @return
     *
     * @throws SQLException
     */
    public static String user(Connection conn) throws SQLException {
	Statement stat = conn.createStatement();
	String    s =
	    "SELECT Value FROM SYSTEM_CONNECTIONINFO WHERE KEY='USER'";
	ResultSet r = stat.executeQuery(s);

	r.next();

	return r.getString(1);
    }

    /**
     * Method declaration
     *
     *
     * @param conn
     *
     * @return
     *
     * @throws SQLException
     */
    public static int identity(Connection conn) throws SQLException {
	Statement stat = conn.createStatement();
	String    s =
	    "SELECT VALUE FROM SYSTEM_CONNECTIONINFO WHERE KEY='IDENTITY'";
	ResultSet r = stat.executeQuery(s);

	r.next();

	return r.getInt(1);
    }

}