


分享一个php图片上传类,且可以自动生成缩略图,有需要的朋友,可以作个参考,希望可以对您有用。
php实现的图片文件上传类,代码: <?php /** 功 能:文件上传类 支持文件夹自动分组保存; 创建类:参数(文件域,文件原名,文件大小); $myupload = new upfileClass($upfile,$upfile_name,$upfile_size); $myupload->savefile(); # 保存方法 并返回保存路径附带文件名; @ echo MakeBuild($BuildFile,$newFile,$File_width); 生成指定文件的缩略图; $myupload->MakeBuild("images/a.jpg","news/b.jpg","100"); */ class upfileClass { var $upfile, $upfile_name, $upfile_size; var $new_upfile_name; # 上传后的文件名称 ; var $fleth, $fileExtent; # 文件扩展名(类型) ; var $f1, $f2, $f3; # 文件保存路径(多级) upfiles/2008-01/08/; var $filename; # 文件(带路径) ; var $maxSize, $File_type; # 允许上传文件的大小 允许上传文件的类型 ; var $BuildFile,$newFile,$File_width,$File_height,$rate; function upfileClass($upfile,$upfile_name,$upfile_size) { $this->upfile = $upfile; $this->upfile_name = $upfile_name; $this->upfile_size = $upfile_size; $this->new_upfile_name = $this->CreateNewFilename($this->upfile_name); $this->f1 = "upfiles"; $this->f2 = $this->f1."/".date('Y')."-".date('m'); $this->f3 = $this->f2."/".date('d'); $this->filename = $this->f3 . "/" . $this->new_upfile_name; $this->maxSize = 500*1024; # 文件大小 500KB $this->File_type = "gif/jpg/jpeg/png"; # 允许上传的文件类型 } # 创建新文件名 (原文件名) function CreateNewFilename($file_name) { $this->fleth = explode(".",$file_name); $this->fileExtent = $this->fleth[(int)count($this->fleth)-1]; # 获取文件后缀; $tmpstr = date('YmdHis') . "." .$this->fileExtent; # 创建新文件名; return $tmpstr; } # 检测文件类型是否正确 function chk_fileExtent() { $iwTrue = 0; $fle = explode("/",$this->File_type); for($i=0; $i < count($fle); $i++){ if( $this->fileExtent == $fle[$i] ) { $iwTrue = (int) $iwTrue + 1; } } if( $iwTrue == 0 ){ $this->msg("文件不符合 ".$this->File_type." 格式!"); } } # 提示错误信息并终止操作 function msg($Error) { echo "<script language=/"javascript/">/n"; echo " alert('".$Error."');/n"; echo " window.history.back();/n"; echo "</script>/n"; die(); } # 保存文件 function savefile() { $this->chk_fileExtent(); $this->chk_fileSize(); $this->CreateFolder( "../".$this->f1 ); $this->CreateFolder( "../".$this->f2 ); $this->CreateFolder( "../".$this->f3 ); return $this->chk_savefile(); } # 检测上传结果是否成功 function chk_savefile() { $copymsg = copy($this->upfile,"../".$this->filename); if( $copymsg ){ return $this->filename; } else{ $this->msg("文件上传失败! /n/n请重新上传! "); } } # 创建文件夹 function CreateFolder($foldername) { if( !is_dir($foldername) ){ mkdir($foldername,0777); } } # 检测文件大小 function chk_fileSize() { if( $this->upfile_size > $this->maxSize ){ $this->msg("目标文件不能大于". $this->maxSize/1024 ." KB"); } } # 删除文件($filePath 文件相对路径) function Deletefile($filePath) { if( !is_file($filePath) ){ return false; } else{ $ending = @unlink($filePath); return $ending; } } /* 函数:生成缩略图 MakeBuild("images/a.jpg","news/b.jpg","100"); 参数: echo $BuildFile; 原图 带路径 echo $newFile; 生成的缩略图 带路径 echo $File_width; 缩略图宽度值 echo $File_height; 缩略图高度值 (默认为宽度的比例值) echo $rate; 缩略图象品质; */ function MakeBuild($BuildFile,$newFile,$File_width,$File_height=0,$rate=100) { if(!is_file($BuildFile)){ $this->msg("文件 ".$BuildFile." 不是一个有效的图形文件!/n/n系统无法生成该文件的缩略图!"); return false; } $data = GetImageSize($BuildFile); switch($data[2]){ case 1: $im = @ImageCreateFromGIF($BuildFile); break; case 2: $im = @ImageCreateFromJPEG($BuildFile); break; case 3: $im = @ImageCreateFromPNG($BuildFile); break; } if(!$im){ return false; } else{ $srcW=ImageSX($im); # 取得原图宽度; $srcH=ImageSY($im); # 取得原图高度; $dstX=0; $dstY=0; if($File_height==0){ $File_height = $File_width/$srcW*$srcH; } if ($srcW*$File_height>$srcH*$File_width){ $fFile_height = round($srcH*$File_width/$srcW); $dstY = floor(($File_height-$fFile_height)/2); $fFile_width = $File_width; } else { $fFile_width = round($srcW*$File_height/$srcH); $dstX = floor(($File_width-$fFile_width)/2); $fFile_height = $File_height; } $ni = ImageCreateTrueColor($File_width,$File_height); $dstX = ($dstX<0)?0:$dstX; $dstY = ($dstX<0)?0:$dstY; $dstX = ($dstX>($File_width/2))?floor($File_width/2):$dstX; $dstY = ($dstY>($File_height/2))?floor($File_height/s):$dstY; ImageCopyResized($ni,$im,$dstX,$dstY,0,0,$fFile_width,$fFile_height,$srcW,$srcH); ImageJpeg($ni,$newFile,$rate); # 生成缩略图; imagedestroy($im); # imagedestroy(resource) 释放image关联的内存 } } } ?> |

Absolute session timeout starts at the time of session creation, while an idle session timeout starts at the time of user's no operation. Absolute session timeout is suitable for scenarios where strict control of the session life cycle is required, such as financial applications; idle session timeout is suitable for applications that want users to keep their session active for a long time, such as social media.

The server session failure can be solved through the following steps: 1. Check the server configuration to ensure that the session is set correctly. 2. Verify client cookies, confirm that the browser supports it and send it correctly. 3. Check session storage services, such as Redis, to ensure that they are running normally. 4. Review the application code to ensure the correct session logic. Through these steps, conversation problems can be effectively diagnosed and repaired and user experience can be improved.

session_start()iscrucialinPHPformanagingusersessions.1)Itinitiatesanewsessionifnoneexists,2)resumesanexistingsession,and3)setsasessioncookieforcontinuityacrossrequests,enablingapplicationslikeuserauthenticationandpersonalizedcontent.

Setting the httponly flag is crucial for session cookies because it can effectively prevent XSS attacks and protect user session information. Specifically, 1) the httponly flag prevents JavaScript from accessing cookies, 2) the flag can be set through setcookies and make_response in PHP and Flask, 3) Although it cannot be prevented from all attacks, it should be part of the overall security policy.

PHPsessionssolvetheproblemofmaintainingstateacrossmultipleHTTPrequestsbystoringdataontheserverandassociatingitwithauniquesessionID.1)Theystoredataserver-side,typicallyinfilesordatabases,anduseasessionIDstoredinacookietoretrievedata.2)Sessionsenhances

PHPsessionscanstorestrings,numbers,arrays,andobjects.1.Strings:textdatalikeusernames.2.Numbers:integersorfloatsforcounters.3.Arrays:listslikeshoppingcarts.4.Objects:complexstructuresthatareserialized.

TostartaPHPsession,usesession_start()atthescript'sbeginning.1)Placeitbeforeanyoutputtosetthesessioncookie.2)Usesessionsforuserdatalikeloginstatusorshoppingcarts.3)RegeneratesessionIDstopreventfixationattacks.4)Considerusingadatabaseforsessionstoragei

Session regeneration refers to generating a new session ID and invalidating the old ID when the user performs sensitive operations in case of session fixed attacks. The implementation steps include: 1. Detect sensitive operations, 2. Generate new session ID, 3. Destroy old session ID, 4. Update user-side session information.


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