从 PHP 会话加载一个对象，它会调用构造函数吗？

Question

如果我将一些对象保存在 php 会话变量 $_SESSION['geoip'] = new GeoIP(); 中，然后在以后的页面加载中我使用 $geoip = $_SESSION['geoip']，它会调用构造函数吗？

我的 GeoIP 类的构造函数正在调用远程 API (CURL)，因此我希望通过仅在第一次执行它然后将结果存储在我的会话变量中来节省 API 调用。

GeoIP.class.php：

require_once('geoPlugin.class.php');

class GeoIP 
{
    public $currentIP;
    public $geoplugin;

    function __construct($forceIP = null){
        if(!empty($forceIP)) $this->currentIP = $forceIP;
        else $this->currentIP = $_SERVER['REMOTE_ADDR'];

        $this->geoplugin = new geoPlugin();
        $this->geoplugin->locate($forceIP);
    }

    function isValid(){
        return !empty($this->geoplugin->countryName);   
    }

    function getCountry(){
        return  $this->geoplugin->countryName;
    }

    function getRegion(){
        return  $this->geoplugin->region;
    }

    function getCity(){
        return  $this->geoplugin->city;     
    }

    function getPostalCode(){
        return $this->geoplugin->postalCode;    
    }



}

geoPlugin.class.php:

<?php
/*
This PHP class is free software: you can redistribute it and/or modify
the code under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version. 

However, the license header, copyright and author credits 
must not be modified in any form and always be displayed.

This class is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

@author geoPlugin (gp_support@geoplugin.com)
@copyright Copyright geoPlugin (gp_support@geoplugin.com)
$version 1.01


This PHP class uses the PHP Webservice of http://www.geoplugin.com/ to geolocate IP addresses

Geographical location of the IP address (visitor) and locate currency (symbol, code and exchange rate) are returned.

See http://www.geoplugin.com/webservices/php for more specific details of this free service

*/

class geoPlugin {

    //the geoPlugin server
    var $host = 'http://www.geoplugin.net/php.gp?ip={IP}&base_currency={CURRENCY}';
    var $postalHost = 'http://www.geoplugin.net/extras/postalcode.gp?lat={LAT}&long={LONG}';

    //the default base currency
    var $currency = 'USD';

    //initiate the geoPlugin vars
    var $ip = null;
    var $city = null;
    var $region = null;
    var $areaCode = null;
    var $dmaCode = null;
    var $countryCode = null;
    var $countryName = null;
    var $continentCode = null;
    var $latitute = null;
    var $longitude = null;
    var $currencyCode = null;
    var $currencySymbol = null;
    var $currencyConverter = null;
    var $postalCode = null;

    function geoPlugin() {

    }

    function locate($ip = null) {

        global $_SERVER;

        if ( is_null( $ip ) ) {
            $ip = $_SERVER['REMOTE_ADDR'];
        }

        $host = str_replace( '{IP}', $ip, $this->host );
        $host = str_replace( '{CURRENCY}', $this->currency, $host );

        $data = array();

        $response = $this->fetch($host);

        $data = unserialize($response);

        //set the geoPlugin vars
        $this->ip = $ip;
        $this->city = $data['geoplugin_city'];
        $this->region = $data['geoplugin_region'];
        $this->areaCode = $data['geoplugin_areaCode'];
        $this->dmaCode = $data['geoplugin_dmaCode'];
        $this->countryCode = $data['geoplugin_countryCode'];
        $this->countryName = $data['geoplugin_countryName'];
        $this->continentCode = $data['geoplugin_continentCode'];
        $this->latitude = $data['geoplugin_latitude'];
        $this->longitude = $data['geoplugin_longitude'];
        $this->currencyCode = $data['geoplugin_currencyCode'];
        $this->currencySymbol = $data['geoplugin_currencySymbol'];
        $this->currencyConverter = $data['geoplugin_currencyConverter'];

        if(!empty($this->latitude) && !empty($this->longitude)){
            $host = str_replace( '{LAT}', $this->latitude, $this->postalHost );
            $host = str_replace( '{LONG}', $this->longitude, $host );
            $data = array();
            $response = $this->fetch($host);
            $data = unserialize($response);

            $this->postalCode = $data['geoplugin_postCode'];
        }

    }

    function fetch($host) {

        if ( function_exists('curl_init') ) {

            //use cURL to fetch data
            $ch = curl_init();
            curl_setopt($ch, CURLOPT_URL, $host);
            curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
            curl_setopt($ch, CURLOPT_USERAGENT, 'geoPlugin PHP Class v1.0');
            $response = curl_exec($ch);
            curl_close ($ch);

        } else if ( ini_get('allow_url_fopen') ) {

            //fall back to fopen()
            $response = file_get_contents($host, 'r');

        } else {

            trigger_error ('geoPlugin class Error: Cannot retrieve data. Either compile PHP with cURL support or enable allow_url_fopen in php.ini ', E_USER_ERROR);
            return;

        }

        return $response;
    }

    function convert($amount, $float=2, $symbol=true) {

        //easily convert amounts to geolocated currency.
        if ( !is_numeric($this->currencyConverter) || $this->currencyConverter == 0 ) {
            trigger_error('geoPlugin class Notice: currencyConverter has no value.', E_USER_NOTICE);
            return $amount;
        }
        if ( !is_numeric($amount) ) {
            trigger_error ('geoPlugin class Warning: The amount passed to geoPlugin::convert is not numeric.', E_USER_WARNING);
            return $amount;
        }
        if ( $symbol === true ) {
            return $this->currencySymbol . round( ($amount * $this->currencyConverter), $float );
        } else {
            return round( ($amount * $this->currencyConverter), $float );
        }
    }

    function nearby($radius=10, $limit=null) {

        if ( !is_numeric($this->latitude) || !is_numeric($this->longitude) ) {
            trigger_error ('geoPlugin class Warning: Incorrect latitude or longitude values.', E_USER_NOTICE);
            return array( array() );
        }

        $host = "http://www.geoplugin.net/extras/nearby.gp?lat=" . $this->latitude . "&long=" . $this->longitude . "&radius={$radius}";

        if ( is_numeric($limit) )
            $host .= "&limit={$limit}";

        return unserialize( $this->fetch($host) );

    }


}

我的来电者：

if(isset($_GET['forceIP'])){ //overwrite the IP address
    $myGeo = new GeoIP($_GET['forceIP']);
}
else{
    if(empty($_SESSION['directory']['geoip'])){
        $myGeo = new GeoIP();
        $_SESSION['directory']['geoip'] = $myGeo;
    }
    else{
        $myGeo = $_SESSION['directory']['geoip'];
    }
}

Answer 1

答案是否定的，因为对象没有被重建。然而，调用的是 magic __sleep() and __wakeup() 方法，当您将其存储到 $_SESSION 时第一个方法，当您检索它时第二个方法。

您应该快速查看this thread，以确保您已经考虑过使用 $_SESSION 存储对象的一些问题。

Answer 2

构造函数只调用一次：创建对象时（使用new 关键字，在您的情况下为new GeoIP()）。