PHP 防止表单重复提交

<?php 

/*

* PHP简单利用token防止表单重复提交

* 此处理方法纯粹是为了给初学者参考

*/ 

session_start(); 

 

var_dump($_POST);

functionset_token() { 

     $_SESSION['token'] = md5(microtime(true)); 

     var_dump($_SESSION['token']);

} 

   

functionvalid_token() { 

    $return= $_REQUEST['token'] === $_SESSION['token'] ? true : false; 

    set_token(); 

    return$return; 

} 

   

//如果token为空则生成一个token 

if(!isset($_SESSION['token']) || $_SESSION['token']=='') { 

    set_token(); 

} 

   

if(isset($_POST['test'])){ 

    if(!valid_token()){ 

        echo"token error"; 

    }else{ 

        echo'成功提交，Value:'.$_POST['test']; 

    } 

} 

?> 

<form method="post"action=""> 

    <input type="hidden"name="token"value="<?php echo $_SESSION['token']?>"> 

    <input type="text"name="test"value="Default"> 

    <input type="submit"value="提交"/> 

</form>