session存储的替代方法redis

<code>bool session_set_save_hanler(callback open,callback close,callback read,callback write,callback destory,callback gc)
</code>

<code><?php

class SessionManager {
    private $reids;
    private $sessionSavePath;
    private $sessionName;
    private $sessi

    public function __construct() {
        $this->reids=new Redis();
        $this->reids->connect('127.0.0.1',6379);

        $retval=session_set_save_handler(
            array($this,"open"),
            array($this,"close"),
            array($this,"read"),
            array($this,"write"),
            array($this,"destroy"),
            array($this,"gc")
        );
}

public function open($path,$name) {
    return true;
}

public function close() {
    return true;
}

public function read($id) {
    $vale=$this->reids->get($id);
    if($vale) {
        return $vale;
    }else {
        return '';
    }
}

public function write($id,$data) {
    if($this->reids->set($id,$data)) {
        $this->reids->expire($id,$this->sessionExpireTime);
        return true;
    }
    return false;
}

public function destroy($id) {
    if($this->reids->delete($id)) {
        return true;
    }
    return false;
}

public function gc($maxlifetime) {
    return true;
}

    public function __destruct() {
        session_write_close();
    }
}

?>
</code>

<code><?php
    include("SessionManager.php");
    new SessionManager(); //开启session管理
    $_SESSION['username']='hezikuang';//创建session变量
?>
</code>

<code><?php
    include("SessionManager.php");
    new SessionManager(); //开启session管理
    echo $_SESSION['username'];
?>
</code>