PHP Strict Standards: Static function DatabaseHandler::init

Question

PHP Strict Standards: Static function DatabaseHandler::init() should not be abstract in databasehandler.php on line 7 PHP Strict Standards: Static function icro\LIB\Database\DatabaseHandler::getInstance() should not be abstract in databasehandler.php on line 8

<?php
namespace Micro\LIB\Database;
abstract class DatabaseHandler
{
    const DATABASE_DRIVER_PDO   =1;
    const DATABASE_DRIVER_MYSQLI=2;
    abstract protected static function init();  //  should not be abstract in
    abstract protected static function getInstance();  //should not be abstract in
    public static function factory()
    {
        $driver = DATABASE_CONN_DRIVER;
        if ($driver == self::DATABASE_DRIVER_PDO) {
            return PDODatabaseHandler::getInstance();
        }elseif($driver == self::DATABASE_DRIVER_MYSQLI){
            return MySQLiDatabasehandler::getInstance();
        };
    }
}