[李景山php]每天laravel-20161119|Connector.php

<?phpnamespace Illuminate\Database\Connectors;use PDO;use Exception;use Illuminate\Support\Arr;use Illuminate\Database\DetectsLostConnections;// that was system classclass Connector{// a connector    use DetectsLostConnections;// a trait like detects lost connections    /**     * The default PDO connection options.     *     * @var array     */    protected $options = [        PDO::ATTR_CASE => PDO::CASE_NATURAL,        PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,        PDO::ATTR_ORACLE_NULLS => PDO::NULL_NATURAL,        PDO::ATTR_STRINGIFY_FETCHES => false,        PDO::ATTR_EMULATE_PREPARES => false,    ];// set all this pdo options    /**     * Get the PDO options based on the configuration.     *     * @param  array  $config     * @return array     */    public function getOptions(array $config)    {        $options = Arr::get($config, 'options', []);// get configs options default is empty array        return array_diff_key($this->options, $options) + $options;// set the new option    }// get options    /**     * Create a new PDO connection.     *     * @param  string  $dsn     * @param  array   $config     * @param  array   $options     * @return \PDO     */    public function createConnection($dsn, array $config, array $options)    {// create a new pdo connection.        $username = Arr::get($config, 'username');//username        $password = Arr::get($config, 'password');// password        try {            $pdo = new PDO($dsn, $username, $password, $options);        } catch (Exception $e) {// try connection this function            $pdo = $this->tryAgainIfCausedByLostConnection(                $e, $dsn, $username, $password, $options// throw exception            );        }        return $pdo;// if ok,just return this pdo function    }    /**     * Get the default PDO connection options.     *     * @return array     */    public function getDefaultOptions()    {        return $this->options;    }// get the default Options by this class    /**     * Set the default PDO connection options.     *     * @param  array  $options     * @return void     */    public function setDefaultOptions(array $options)    {        $this->options = $options;    }// can set the default options in this way    /**     * Handle a exception that occurred during connect execution.     *     * @param  \Exception  $e     * @param  string  $dsn     * @param  string  $username     * @param  string  $password     * @param  array   $options     * @return \PDO     *     * @throws \Exception     */    protected function tryAgainIfCausedByLostConnection(Exception $e, $dsn, $username, $password, $options)    {//Handle a exception that occurred during connect execution        if ($this->causedByLostConnection($e)) {            return new PDO($dsn, $username, $password, $options);        }        throw $e;    }// throw $e}