本文实例讲述了PHP文件上传类。分享给大家供大家参考，具体如下：
这里演示了FileUpload.class.php文件上传类，其中用到了两个常量，可在网站配置文件中定义：
define('ROOT_PATH',dirname(__FILE__)); //网站根目录define('UPDIR','/uploads/'); //上传主目录 具体代码如下：
<?php //上传文件类 class FileUpload { private $error; //错误代码 private $maxsize; //表单最大值 private $type; //类型 private $typeArr = array('image/jpeg','image/pjpeg','image/png','image/x-png','image/gif'); //类型合集 private $path; //目录路径 private $today; //今天目录 private $name; //文件名 private $tmp; //临时文件 private $linkpath; //链接路径 private $linktotay; //今天目录（相对） //构造方法，初始化 public function __construct($_file,$_maxsize) { $this->error = $_FILES[$_file]['error']; $this->maxsize = $_maxsize / 1024; $this->type = $_FILES[$_file]['type']; $this->path = ROOT_PATH.UPDIR; $this->linktotay = date('Ymd').'/'; $this->today = $this->path.$this->linktotay; $this->name = $_FILES[$_file]['name']; $this->tmp = $_FILES[$_file]['tmp_name']; $this->checkError(); $this->checkType(); $this->checkPath(); $this->moveUpload(); } //返回路径 public function getPath() { $_path = $_SERVER["SCRIPT_NAME"]; $_dir = dirname(dirname($_path)); if ($_dir == '//') $_dir = '/'; $this->linkpath = $_dir.$this->linkpath; return $this->linkpath; } //移动文件 private function moveUpload() { if (is_uploaded_file($this->tmp)) { if (!move_uploaded_file($this->tmp,$this->setNewName())) { Tool::alertBack('警告：上传失败！'); } } else { Tool::alertBack('警告：临时文件不存在！'); } } //设置新文件名 private function setNewName() { $_nameArr = explode('.',$this->name); $_postfix = $_nameArr[count($_nameArr)-1]; $_newname = date('YmdHis').mt_rand(100,1000).'.'.$_postfix; $this->linkpath = UPDIR.$this->linktotay.$_newname; return $this->today.$_newname; } //验证目录 private function checkPath() { if (!is_dir($this->path) || !is_writeable($this->path)) { if (!mkdir($this->path)) { Tool::alertBack('警告：主目录创建失败！'); } } if (!is_dir($this->today) || !is_writeable($this->today)) { if (!mkdir($this->today)) { Tool::alertBack('警告：子目录创建失败！'); } } } //验证类型 private function checkType() { if (!in_array($this->type,$this->typeArr)) { Tool::alertBack('警告：不合法的上传类型！'); } } //验证错误 private function checkError() { if (!empty($this->error)) { switch ($this->error) { case 1 : Tool::alertBack('警告：上传值超过了约定最大值！'); break; case 2 : Tool::alertBack('警告：上传值超过了'.$this->maxsize.'KB！'); break; case 3 : Tool::alertBack('警告：只有部分文件被上传！'); break; case 4 : Tool::alertBack('警告：没有任何文件被上传！'); break; default: Tool::alertBack('警告：未知错误！'); } } } }?> 其中，用到了一个静态工具类 Tool.class.php，代码如下：
Tool.class.php
<?php class Tool { //弹窗返回 static public function alertBack($_info) { echo "<script type='text/javascript'>alert('$_info');history.back();</script>"; exit(); } //弹窗赋值关闭 static public function alertOpenerClose($_info,$_path) { echo "<script type='text/javascript'>alert('$_info');</script>"; echo "<script type='text/javascript'>opener.document.content.thumbnail.value='$_path';</script>"; echo "<script type='text/javascript'>opener.document.content.pic.style.display='block';</script>"; echo "<script type='text/javascript'>opener.document.content.pic.src='$_path';</script>"; echo "<script type='text/javascript'>window.close();</script>"; exit(); } }?> 下面进行一个实例演示，请看下面的步骤：
1、先创建一个 index.php 页面，做一个表单
index.php
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN""http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>main</title> </head> <body> <form name="content" method="post" action="?action=add"> <input type="text" name="thumbnail" class="text" readonly="readonly" /> <input type="button" value="上传" onclick="centerWindow('./upfile.html','upfile','400','100')" /> <img name="pic" style="display:none;" /> ( * 必须是jpg,gif,png，并且200k内) <br /> </form> </body></html> 2、创建 upfile.html 文件，建立表单提交到 upload.php
upfile.html
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <title>上传图片</title> </head> <body></p><p> <form method="post" action="./upload.php" enctype="multipart/form-data" style="text-align:center;margin:30px;"> <input type="hidden" name="MAX_FILE_SIZE" value="204800" /> <input type="file" name="pic" /> <input type="submit" name="send" value="确定上传" /></form></p><p></body></html>
3、通过 upload.php 文件调用文件上传类实现上传，并且把路径赋给 input 标签和显示图片
<?php require 'FileUpload.class.php'; if (isset($_POST['send'])) { $_fileupload = new FileUpload('pic',$_POST['MAX_FILE_SIZE']); $_path = $_fileupload->getPath(); Tool::alertOpenerClose('文件上传成功！',$_path); } else { Tool::alertBack('警告：文件过大或者其他未知错误导致浏览器崩溃！'); }?> 
