Session技术笔记

发表于   |   分类于   |     |   阅读量 次

  1. session执行原理
    客户端 登录 服务器， 在服务器上存储了session， 服务器会为该客户端创建一个session文件，
    并把 session id 存储到 客户端的cookie上

  2. 关于session的配置

    session.save_handler = files            session保存在文件中
session.save_path = "c:/wamp/tmp"        保存文件的路径
session.use_cookies = 1                    是否使用cookie
session.use_only_cookies = 1            是否只使用cookie
session.name = PHPSESSID                cookie中sessionid的键名
session.auto_start = 0                    是否自动开启session
session.cookie_lifetime = 0                sessionid在 cookie的生存周期
session.cookie_path = /
session.cookie_domain =
session.cookie_httponly = 
session.serialize_handler = php            文件中存储session数据的方法
session.gc_probability = 1
session.gc_divisor = 1000
session.gc_maxlifetime = 1440            session默认保存时间 秒
session.use_trans_sid = 0

  3. 自定义session
    ① 设置 session的处理 方式为 用户自定义

    session_module_name('user') 或  ini_set('')

    ② 设置回调函数 控制session的处理流程

    session_set_save_handler(open, close, read, werite, destroy, gc)
open(sess_path, sess_name)
close()
read(sess_id)
write(sess_id, sess_data)
destroy(sess_id)
gc(sess_lifetime)

  4. session存储在 自定义文件中
    它的意义不大就不说了

  5. session存储在 数据库中
    定义一个类来执行操作
    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    31
    32
    33
    34
    35
    36
    37
    38
    39
    40
    41
    42
    43
    44
    45
    46
    47
    48
    49
    50
    51
    52
    53
    54
    55
    56
    57
    58
    59
    60
    61
    62
    63
    64
    65
    66
    67
    68
    69
    70
    71
    72
    73
    74
    75
    76
    77
    78
    79
    80
    81
    82
    83
    84
    85
    86
    87
    <?php 
    //session驱动 存储于 数据库
    class DbSession{
    	private static $pdo;

    	//初始化
    	public static function start(PDO $pdo){
    		self::$pdo = $pdo;		//给属性赋值
    		//设置session
    		session_module_name('user');
    		session_set_save_handler(
    			array(__CLASS__, 'open'),
    			array(__CLASS__, 'close'),
    			array(__CLASS__, 'read'),
    			array(__CLASS__, 'write'),
    			array(__CLASS__, 'destroy'),
    			array(__CLASS__, 'gc')
    		);
    		session_start();
    	}

    	//open
    	public static function open($sess_path, $sess_name){
    		return true;
    	}

    	//close
    	public static function close(){
    		return true;
    	}

    	//read
    	public static function read($sess_id){
    		$sql = "select sess_data from session where sess_id=?";
    		$stmt = self::$pdo->prepare($sql);
    		$stmt->execute(array($sess_id));
    		$stmt->bindColumn('sess_data', $sess_data);
    		$stmt->fetch();
    		return $sess_data;
    	}

    	//write
    	public static function write($sess_id, $sess_data) {
    		//判断 之前是否 存储过session
    		$sql = "select sess_data from session where sess_id=?";
    		$stmt = self::$pdo->prepare($sql);
    		$stmt->execute(array($sess_id));
    		if ($stmt->rowCount() > 0) {
    			//更新
    			$sql = "update session set sess_data=?, sess_time=? where sess_id=?";
    			$stmt = self::$pdo->prepare($sql);
    			$stmt->execute(array($sess_data, time(), $sess_id));
    		} else {
    			//插入
    			$sql = "insert into session(sess_id, sess_data, sess_time) values(?,?,?)";
    			$stmt = self::$pdo->prepare($sql);
    			$stmt->execute(array($sess_id, $sess_data, time()));
    		}
    	}

    	//destroy
    	public static function destroy($sess_id){
    		$sql = "delete from session where sess_id=?";
    		$stmt = self::$pdo->prepare($sql);
    		$stmt->execute(array($sess_id));
    		return true;
    	}

    	//gc
    	public static function gc($sess_lifetime){
    		$sql = "delete from session where sess_time<".(time()-$sess_lifetime);
    		$stmt = self::$pdo->prepare($sql);
    		$stmt->execute();
    	}
    	
    }

    try {
    	$pdo = new PDO('mysql:host=localhost;dbname=s33', 'root', '123456');
    	$pdo->exec('set names utf8');
    } catch (PDOException $e) {
    	echo $e->getMessage();exit;
    }

    //初始化
    DbSession::start($pdo);
    ?>

数据库建表

1
2
3
4
5
create table session(
	sess_id char(32) not null primary key,
	sess_data text not null,
	sess_time int not null
)engine=innodb default charset=utf8;

测试

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
<?php 
header("Content-type:text/html;charset=utf-8");
require "./DbSession.class.php";


$_SESSION['username'] = "jiabrother";
$_SESSION['age'] = "45";
$_SESSION['grade'] = "s33";

//session_destroy();

echo "<hr>";

var_dump($_SESSION);
var_dump($_COOKIE);

?>
<a href="2.php">2.php</a>

  1. session存储在 memcache
    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    <?php 
    header("Content-type:text/html;charset=utf-8");

    ini_set('session.save_handler', 'memcache');
    ini_set('session.save_path', '127.0.0.1:11211');

    session_start();


    $_SESSION['username'] = "jiabrother";
    $_SESSION['age'] = "45";
    $_SESSION['grade'] = "s33";

    //session_destroy();

    echo "<hr>";

    var_dump($_SESSION);
    var_dump($_COOKIE);

    ?>
    <a href="2.php">2.php</a>

测试

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
<?php 
header("Content-type:text/html;charset=utf-8");
ini_set('session.save_handler', 'memcache');
ini_set('session.save_path', '127.0.0.1:11211');

session_start();

var_dump($_SESSION);
var_dump($_COOKIE);


$mem = new Memcache();
$mem->addServer('127.0.0.1', 11211);

echo $mem->get('okgmpf6dije13a88u4ikad6h31');
 ?>

本文出自 “小风博客” BY:小风 如果你喜欢,转载请务必保留此出处^_^
小风博客  http://www.xfphp.cn  小风网络 http://www.hotxf.com