我有一个面向对象的PHP登录系统，使用jQuery AJAX成功登录用户，但在重定向到新的网页（或返回URL）时，$SESSION信息丢失。代码有什么问题？
编辑/更新：我发现当我分配、查看/回显$_SESSION变量时，这个问题会在任何页面上发生。有些地方不对。这是我的php.ini文件中关于SESSIONS的副本。
[Session]
; Handler used to store/retrieve data.
; http://php.net/session.save-handler
session.save_handler = files
; Argument passed to save_handler. In the case of files, this is the path
; where data files are stored. Note: Windows users have to change this
; variable in order to use PHP's session functions.
;
; The path can be defined as:
;
; session.save_path = "N;/path"
;
; where N is an integer. Instead of storing all the session files in
; /path, what this will do is use subdirectories N-levels deep, and
; store the session data in those directories. This is useful if you
; or your OS have problems with lots of files in one directory, and is
; a more efficient layout for servers that handle lots of sessions.
;
; NOTE 1: PHP will not create this directory structure automatically.
; You can use the script in the ext/session dir for that purpose.
; NOTE 2: See the section on garbage collection below if you choose to
; use subdirectories for session storage
;
; The file storage module creates files using mode 600 by default.
; You can change that by using
;
; session.save_path = "N;MODE;/path"
;
; where MODE is the octal representation of the mode. Note that this
; does not overwrite the process's umask.
; http://php.net/session.save-path
session.save_path = "/var/php_sessions"
; Whether to use cookies.
; http://php.net/session.use-cookies
session.use_cookies = 1
; http://php.net/session.cookie-secure
;session.cookie_secure =
; This option forces PHP to fetch and use a cookie for storing and maintaining
; the session id. We encourage this operation as it's very helpful in combating
; session hijacking when not specifying and managing your own session id. It is
; not the end all be all of session hijacking defense, but it's a good start.
; http://php.net/session.use-only-cookies
session.use_only_cookies = 1
; Name of the session (used as cookie name).
; http://php.net/session.name
session.name = PHPSESSID
; Initialize session on request startup.
; http://php.net/session.auto-start
session.auto_start = 1
; Lifetime in seconds of cookie or, if 0, until browser is restarted.
; http://php.net/session.cookie-lifetime
session.cookie_lifetime = 0
; The path for which the cookie is valid.
; http://php.net/session.cookie-path
session.cookie_path = /
; The domain for which the cookie is valid.
; http://php.net/session.cookie-domain
session.cookie_domain =
; Whether or not to add the httpOnly flag to the cookie, which makes it inaccessible to browser scripting languages such as JavaScript.
; http://php.net/session.cookie-httponly
session.cookie_httponly =
; Handler used to serialize data. php is the standard serializer of PHP.
; http://php.net/session.serialize-handler
session.serialize_handler = php
; Defines the probability that the 'garbage collection' process is started
; on every session initialization. The probability is calculated by using
; gc_probability/gc_divisor. Where session.gc_probability is the numerator
; and gc_divisor is the denominator in the equation. Setting this value to 1
; when the session.gc_divisor value is 100 will give you approximately a 1% chance
; the gc will run on any give request.
; Default Value: 1
; Development Value: 1
; Production Value: 1
; http://php.net/session.gc-probability
session.gc_probability = 1
; Defines the probability that the 'garbage collection' process is started on every
; session initialization. The probability is calculated by using the following equation:
; gc_probability/gc_divisor. Where session.gc_probability is the numerator and
; session.gc_divisor is the denominator in the equation. Setting this value to 1
; when the session.gc_divisor value is 100 will give you approximately a 1% chance
; the gc will run on any give request. Increasing this value to 1000 will give you
; a 0.1% chance the gc will run on any give request. For high volume production servers,
; this is a more efficient approach.
; Default Value: 100
; Development Value: 1000
; Production Value: 1000
; http://php.net/session.gc-divisor
session.gc_divisor = 1000
; After this number of seconds, stored data will be seen as 'garbage' and
; cleaned up by the garbage collection process.
; http://php.net/session.gc-maxlifetime
session.gc_maxlifetime = 1440
; NOTE: If you are using the subdirectory option for storing session files
; (see session.save_path above), then garbage collection does *not*
; happen automatically. You will need to do your own garbage
; collection through a shell script, cron entry, or some other method.
; For example, the following script would is the equivalent of
; setting session.gc_maxlifetime to 1440 (1440 seconds = 24 minutes):
; find /path/to/sessions -cmin +24 | xargs rm
; PHP 4.2 and less have an undocumented feature/bug that allows you to
; to initialize a session variable in the global scope, even when register_globals
; is disabled. PHP 4.3 and later will warn you, if this feature is used.
; You can disable the feature and the warning separately. At this time,
; the warning is only displayed, if bug_compat_42 is enabled. This feature
; introduces some serious security problems if not handled correctly. It's
; recommended that you do not use this feature on production servers. But you
; should enable this on development servers and enable the warning as well. If you
; do not enable the feature on development servers, you won't be warned when it's
; used and debugging errors caused by this can be difficult to track down.
; Default Value: On
; Development Value: On
; Production Value: Off
; http://php.net/session.bug-compat-42
session.bug_compat_42 = Off
; This setting controls whether or not you are warned by PHP when initializing a
; session value into the global space. session.bug_compat_42 must be enabled before
; these warnings can be issued by PHP. See the directive above for more information.
; Default Value: On
; Development Value: On
; Production Value: Off
; http://php.net/session.bug-compat-warn
session.bug_compat_warn = Off
; Check HTTP Referer to invalidate externally stored URLs containing ids.
; HTTP_REFERER has to contain this substring for the session to be
; considered as valid.
; http://php.net/session.referer-check
session.referer_check =
; How many bytes to read from the file.
; http://php.net/session.entropy-length
session.entropy_length = 0
; Specified here to create the session id.
; http://php.net/session.entropy-file
; On systems that don't have /dev/urandom /dev/arandom can be used
; On windows, setting the entropy_length setting will activate the
; Windows random source (using the CryptoAPI)
session.entropy_file = /dev/urandom
; Set to {nocache,private,public,} to determine HTTP caching aspects
; or leave this empty to avoid sending anti-caching headers.
; http://php.net/session.cache-limiter
session.cache_limiter = nocache
; Document expires after n minutes.
; http://php.net/session.cache-expire
session.cache_expire = 180
; trans sid support is disabled by default.
; Use of trans sid may risk your users security.
; Use this option with caution.
; - User may send URL contains active session ID
; to other person via. email/irc/etc.
; - URL that contains active session ID may be stored
; in publicly accessible computer.
; - User may access your site with the same session ID
; always using URL stored in browser's history or bookmarks.
; http://php.net/session.use-trans-sid
session.use_trans_sid = 1
; Select a hash function for use in generating session ids.
; Possible Values
; 0 (MD5 128 bits)
; 1 (SHA-1 160 bits)
; This option may also be set to the name of any hash function supported by
; the hash extension. A list of available hashes is returned by the hash_algos()
; function.
; http://php.net/session.hash-function
session.hash_function = 0
; Define how many bits are stored in each character when converting
; the binary hash data to something readable.
; Possible values:
; 4 (4 bits: 0-9, a-f)
; 5 (5 bits: 0-9, a-v)
; 6 (6 bits: 0-9, a-z, A-Z, "-", ",")
; Default Value: 4
; Development Value: 5
; Production Value: 5
; http://php.net/session.hash-bits-per-character
session.hash_bits_per_character = 4
; The URL rewriter will look for URLs in a defined set of HTML tags.
; form/fieldset are special; if you include them here, the rewriter will
; add a hidden <input> field with the info which is otherwise appended
; to URLs. If you want XHTML conformity, remove the form entry.
; Note that all valid entries require a "=", even if no value follows.
; Default Value: "a=href,area=href,frame=src,form=,fieldset="
; Development Value: "a=href,area=href,frame=src,input=src,form=fakeentry"
; Production Value: "a=href,area=href,frame=src,input=src,form=fakeentry"
; http://php.net/url-rewriter.tags
url_rewriter.tags = "a=href,area=href,frame=src,input=src,form=,fieldset="
我有最初的登录页面login.php（其中包含jQuery AJAX）。
<?php
session_start();
?>
<html>
<head>
<script type="text/javascript" src="http://static.fluxexchange.com/fluxexchange/js/jquery-1.8.3.min.js"></script>
</head>
<body>
<form action="" id="login" class="network_login" onSubmit="return false;">
<h3>Sign in to share your cultures and interests with friends.</h3>
<div>
<label>Handle, Email, or Phone</label><input name="handle" id="login-handle" class="login_input">
</div>
<div>
<label>Passcode</label><input name="password" id="login-password" class="login_input" type="password">
</div>
<div>
<input class="auto-authenticate" type="checkbox" style="border:0px;"><label style="width:auto;">Keep me authenticated</label>
</div>
<?php
$iredirect_url=$_GET['return_url'];
?>
<input type="hidden" name="return_url" value="<?php echo $iredirect_url; ?>">
<label id="login_submit_button" class="login_button">
<input class="login-button-blue" value="Authenticate" type="submit">
</label>
<div id="login-loader" class="loader"></div>
<span class="login-option" id="more-login-options">I'm looking for more login options.</span>
</form>
$(function(){
$("#login-loader").hide();
$("#login-success-notification").hide();
$("#login_submit_button").click(function(){
$("#login-loader").fadeIn(1000);
authenticateUser();
});
});
function authenticateUser(){
$.ajax({
type:"POST",
url:"engine/authenticate_user.php",
cache:false,
data: $("#login").serialize(),
dataType:"json",
async:false,
success: function(resp){
console.log(resp);
$('.reg-error-notification').empty();
$('.reg-error-notification').hide();
if(resp.logged_in=="true"){
$("#login-success-notification").append('<p>'+resp.session_test+'</p>').fadeIn(1000, function(){
window.location.href=resp.return_url;
});
} else {
$("#login-loader").fadeOut(1000);
$('#login-error-notification').append('<p>The handle you entered is incorrect. Please try again.</p>').fadeIn(1000);
}
},
});
}
</body>
</html>
还有index.php（当问题发生时重定向到登录页面）。
<?
session_start();
print_r($_SESSION['network_id']);
?>
以及 authenticate_user.php
<?php
session_start();
require("login-classes.php");
$Authenticate= new Authenticate($_POST['handle'], $_POST['password'], $_POST['network'], $_POST['fenetwork']);
$Authenticate->authenticateUser();
$result=array();
if($Authenticate->isLoggedIn()){
$result['logged_in']="true";
$result['return_url']=($_POST['return_url']);
$result['session_test']=$_SESSION['network_id'];
} else {
$result['logged_in']="false";
}
echo json_encode($result);
?>
login-classes.php（包含在authenticate_user.php中）
<?php
//(C) Flux Exchange Network, Inc.
require ("database-classes.php");
class Authenticate {
public function __construct($username, $password, $network_site, $parent_network) {
$this->handle=$username;
$this->password=crypt($password, $this->salt);
$this->parent_network=$parent_network;
$this->network_site=$network_site;
}
public function authenticateUser(){
$database=new Database();
$database->getConnection();
$database->startConnection();
$authenticate_q=mysql_query("SELECT network_users.network_id
FROM network_users
WHERE network_users.handle = '$this->handle'
AND network_users.password ='$this->password'
LIMIT 1");
if(mysql_num_rows($authenticate_q)==1){
$this->isLoggedIn=true;
$user=mysql_fetch_array($authenticate_q);
$this->network_id=$user['network_id'];
$this->setNetworkId();
} else{
//header('HTTP/1.1 500 Internal Server Error');
//die("Something went wrong.");
}
}
function isLoggedIn(){
return $this->isLoggedIn;
}
function addError($error){
$this->error_list[]=$error;
}
function setNetworkId(){
$_SESSION['network_id']=$this->network_id;
}
private $network_id, $handle, $password, $network_site, $parent_network, $error_list, $isLoggedIn=false,
$salt="PRIVATE INFO";
}
?>