如何使用Redis保存用户会话Session详解

session.save_handler = redis

?php 
class SessionManager{

 private $redis;
 private $sessionSavePath;
 private $sessionName;
 private $sessionExpireTime = 60;//redis，session的过期时间为30s

 public function __construct(){
 $this->redis = new Redis();//创建phpredis实例
 $this->redis->connect('127.0.0.1', 6379);//连接redis
 //$this->redis->auth("123456x");//授权
 $retval = session_set_save_handler(
 array($this,"open"),
 array($this,"close"),
 array($this,"read"),
 array($this,"write"),
 array($this,"destroy"),
 array($this,"gc")
 );
 session_start();
 }

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

 public function close(){
 return true;
 }

 public function read($id){
 $value = $this->redis->get($id);//获取redis中的指定记录
 if($value){
 return $value;
 }else{
 return '';
 }
 }

 public function write($id,$data){
 if($this->redis->set($id,$data)){//以session ID为键，存储
 $this->redis->expire($id,$this->sessionExpireTime);//设置redis中数据的过期时间，即session的过期时间
 return true;
 }

 return false;
 }

 public function destroy($id){
 if($this->redis->delete($id)){//删除redis中的指定记录
 return true;
 }
 return false;
 }

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

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

?php 
require_once 'SessionManager.php';
new SessionManager();
$_SESSION['username'] = 'helloweba';

?php 
require_once 'SessionManager.php';
new SessionManager();
echo $_SESSION['username'];