@Override
    public void setCreationDate(String username, Date creationDate) throws UserNotFoundException {
        Connection con = null;
        PreparedStatement pstmt = null;
        try {
            con = DbConnectionManager.getConnection();
            pstmt = con.prepareStatement(UPDATE_CREATION_DATE);
            pstmt.setString(1, StringUtils.dateToMillis(creationDate));
            pstmt.setString(2, username);
            pstmt.executeUpdate();
        }
        catch (SQLException sqle) {
            throw new UserNotFoundException(sqle);
        }
        finally {
            DbConnectionManager.closeConnection(pstmt, con);
        }
    }
Default implementation of the UserProvider interface, which reads and writes data
from the {@code ofUser} database table.<p>

Passwords can be stored as plain text, or encrypted using Blowfish. The
encryption/decryption key is stored as the Openfire property {@code passwordKey},
which is automatically created on first-time use. It's critical that the password key
not be changed once created, or existing passwords will be lost. By default
passwords will be stored encrypted. Plain-text password storage can be enabled
by setting the Openfire property {@code user.usePlainPassword} to {@code true}.

@author Matt Tucker
xmppserver/src/main/java/org/jivesoftware/openfire/user/DefaultUserProvider.java