使用session_set_save_handler()函数，将Session的内容写入数据库
<?php /* *@author Fahy *数据库为mysql， *数据库名为session，表名为session， *表中字段包括PHPSESSID,update_time,client_ip,data */ class Session{ private static $handler = null; private static $ip = null; private static $lifetime = null; private static $time = null; //配置静态变量 private static function init($handler){ self::$handler = $handler; //获取数据库资源 self::$ip = !empty($_SERVER["REMOTE_ADDR"])? $_SERVER["REMOTE_ADDR"]:'unkonw'; //获取客户端ip self::$lifetime = ini_get('session.gc_maxlifetime'); //获取session生命周期 self::$time = time(); //获取当前时间 } //调用session_set_save_handler()函数并开启session static function start($pdo){ self::init($pdo); session_set_save_handler( array(__CLASS__,'open'), array(__CLASS__,'close'), array(__CLASS__,'read'), array(__CLASS__,'write'), array(__CLASS__,'destroy'), array(__CLASS__,'gc') ); session_start(); } public static function open($path,$name){ return true; } public static function close(){ return true; } //查询数据库中的数据 public static function read($PHPSESSID){ $sql = "select PHPSESSID,update_time,client_ip,data from session where PHPSESSID=?"; $stmt = self::$handler->prepare($sql); $stmt->execute(array($PHPSESSID)); if(!$result = $stmt->fetch(PDO::FETCH_ASSOC)){ return ''; } if(self::$ip == $result['client_ip']){ self::destroy($PHPSESSID); return ''; } if(($result['update_time']+self::$lifetime)<self::$time){ self::destroy($PHPSESSID); return ''; } return $result['data']; } /* *首先查询该session是否存在数据，如果存在，则更新数据，如果不存在，则插入数据 */ //将session写入数据库中，$data传入session中的keys和values数组 public static function write($PHPSESSID,$data){ $sql = "select PHPSESSID,update_time,client_ip,data from session where PHPSESSID=?"; $stmt = self::$handler->prepare($sql); $stmt->execute(array($PHPSESSID)); if($result=$stmt->fetch(PDO::FETCH_ASSOC)){ if($result['data'] != $data || self::$time > ($result['update_time']+30)){ $sql = "update session set update_time=?,data=? where PHPSESSID = ?"; $stmt = self::$handler->prepare($sql); $stmt->execute(array($self::$time,$data,$PHPSESSID)); } }else{ if(!empty($data)){ try{ $sql = "insert into session(PHPSESSID,update_time,client_ip,data) values(?,?,?,?)"; }catch(PDOException $e){ echo $e->getMessage(); } $sth = self::$handler->prepare($sql); $sth->execute(array($PHPSESSID,self::$time,self::$ip,$data)); } } return true; } public static function destroy($PHPSESSID){ $sql = "delete from session where PHPSESSID = ?"; $stmt = self::$handler->prepare($sql); $stmt->execute(array($PHPSESSID)); return true; } public static function gc($lifetime){ $sql = "delete from session where update_time<?"; $stmt = self::$handler->prepare($sql); $stmt->execute(array(self::$time-$lifetime)); return true; } } //使用PDO连接数据库 try{ $pdo = new PDO("mysql:host=localhost;dbname=session","root","hwj193"); }catch(PDOException $e){ echo $e->getMessage(); } //传递数据库资源 Session::start($pdo);