public UserDTO getUserByNickname( String nickname ) throws DAOException{
		UserDTO user = null;
		
		query =  "";
		query += "SELECT \n";
		query += "id, passwd, register_date, email, status \n";
		query += "FROM chat_user \n";
		query += "WHERE nickname = ? \n";
		
		try{
			connection = DBManager.getConnection( );
			statement =  connection.prepareStatement( query );
			statement.clearParameters( );
			
			statement.setString( 1 , nickname );
			
			resultSet = statement.executeQuery( );
			
			if( resultSet.next( ) ){
				user = new UserDTO( );
				user.setId( resultSet.getInt( 1 ) );
				user.setNickname( nickname );
				user.setPasswd( resultSet.getString( 2 ) );
				user.setRegisterDate( resultSet.getDate( 3 ) );
				user.setEmail( resultSet.getString( 4 ) );
				user.setStatus( resultSet.getInt( 5 ) );
			} else{
				logger.error( "Can't find user:DBERROR" );
				throw new DataBaseException( );
			}
			
		} catch( SQLException e ) {
			logger.error( "Can't get prepared statement from connection:DBERROR" );
			throw new DAOException( );
		} catch ( DataBaseException e ) {
			logger.error( "Unable to get user register:DBERROR" );
			throw new DAOException( );
		} finally{
			try {
				statement.close( );
			} catch ( SQLException e ) {
				logger.error( "Can't close statement:DBERROR" );
			}
			try {
				resultSet.close( );
			} catch ( SQLException e ) {
				logger.error( "Can't close result set:DBERROR" );
			}
			try {
				connection.close( );
			} catch ( SQLException e ) {
				logger.error( "Can't close connection:DBERROR" );
			}
		}
		return user;
	}