将Session写入数据库

使用session_set_save_handler()函数，将Session的内容写入数据库

  1 php
  2     /*
  3     *@author    Fahy
  4     *@link    http://home.cnblogs.com/u/HuangWj
  5     *数据库为mysql，
  6     *数据库名为session，表名为session，
  7     *表中字段包括PHPSESSID,update_time,client_ip,data
  8     */
  9     class Session{
 10         private static $handler = null;
 11         private static $ip = null;
 12         private static $lifetime = null;
 13         private static $time = null;
 14         
 15         //配置静态变量
 16         private static function init($handler){
 17             self::$handler = $handler;        //获取数据库资源
 18             self::$ip = !empty($_SERVER["REMOTE_ADDR"])? $_SERVER["REMOTE_ADDR"]:'unkonw';        //获取客户端ip
 19             self::$lifetime = ini_get('session.gc_maxlifetime');        //获取session生命周期
 20             self::$time = time();        //获取当前时间
 21         }
 22         //调用session_set_save_handler()函数并开启session
 23         static function start($pdo){
 24             self::init($pdo);
 25             session_set_save_handler(
 26                 array(__CLASS__,'open'),
 27                 array(__CLASS__,'close'),
 28                 array(__CLASS__,'read'),
 29                 array(__CLASS__,'write'),
 30                 array(__CLASS__,'destroy'),
 31                 array(__CLASS__,'gc')
 32             );
 33             session_start();
 34         }
 35         
 36         public static function open($path,$name){
 37             return true;
 38         }
 39         public static function close(){
 40             return true;
 41         }
 42         
 43         //查询数据库中的数据
 44         public static function read($PHPSESSID){
 45              $sql = "select PHPSESSID,update_time,client_ip,data from session where PHPSESSID=?";
 46              $stmt = self::$handler->prepare($sql);
 47              $stmt->execute(array($PHPSESSID));
 48              if(!$result = $stmt->fetch(PDO::FETCH_ASSOC)){
 49                  return '';
 50              }
 51              if(self::$ip == $result['client_ip']){
 52                  self::destroy($PHPSESSID);
 53                  return '';
 54              }
 55              if(($result['update_time']+self::$lifetime)<:>$time