虽然这个文件上传类看起来很凌乱，但却是非常好用的，其中可以定义上传的文件类型，上传的文件大小等等，主要的是可以随时开启错误记录，当我们上传文件无法成功时，会给出错误的提示，比如没有文件被上传，文件只被部分上传，上传文件上传超过了Html表单中MAX_FILE_SIZE选项指定的值，上传文件超过了xiariboke.net配置文件php.ini中upload_max_size选项指定的值，不被允许的文件类型等等。可以让我们很清楚的知道错误在哪里。。

在php中有许多优秀的文件上传类，如果文件未被上传成功，通常都会留有一串英文的错误，看起来很难懂，如果换成中文的错误字符，我们就可以第一时间知道什么地方出错了。

<?php
class FileUploadClass{
//these file name of private vars must to lower.
private $filepath;
private $allowtype=array("gif","jpg","png","jpeg","bmp");
private $maxsize=5000000;
private $randname=true;
//these file name of private vars could be lower or upper.
private $sourceName;
private $tempName;
private $fileType;
private $fileSize;
private $newFileName;
private $errorNum=0;
private $errorMsg="";

function __construct($option=array()){
foreach($option as $key=>$value){
$key=strtolower($key);
if(in_array($key,get_class_vars(get_class($this)))){
$this->setOptions($key,$value);
}else{
continue;
}
}
}

private function getErrorStr(){
$str="上传文件<font color='blue'>{$this->sourceName}</font>时出错:";
switch($this->errorNum){
case 4: $str.="<font color='red'>没有文件被上传</font>";break;
case 3: $str.="<font color='red'>文件只被部分上传</font>";break;
case 2: $str.="<font color='red'>上传文件上传超过了Html表单中MAX_FILE_SIZE选项指定的值</font>";break;
case 1: $str.="<font color='red'>上传文件超过了xiariboke.net配置文件php.ini中upload_max_size选项指定的值</font>";break;
case -1: $str.="<font color='red'>不被允许的文件类型</font>";break;
case -2: $str.="<font color='red'>文件过大,上传文件不能超过{$this->maxsize}个字节</font>";break;
case -3: $str.="<font color='red'>上传失败</font>";break;
case -4: $str.="<font color='red'>建立存放上传文件目录失败,请重新指定上传目录</font>";break;
case -5: $str.="<font color='red'>必须指定上传文件的路径</font>";break;
default: $str.="<font color='red'>未知的错误</font>";
}
return $str;
}

private function checkFilePath(){
if(empty($this->filepath)){
$this->setOptions("errorNum",-5);
return false;
}
if(file_exists($this->filepath) && is_writeable($this->filepath)){
return true;
}else{
if(@mkdir($this->filepath,0755)){
return true;
}else{
$this->setOptions("errorNum",-4);
return false;
}
}
}

private function checkFileType(){
if(in_array(strtolower($this->fileType),$this->allowtype)){
return true;
}else{
$this->setOptions("errorNum",-1);
return false;
}
}

private function checkFileSize(){
if($this->fileSize>$this->maxsize){
$this->setOptions("errorNum",-2);
return false;
}else{
return true;
}
}

private function fileRandName(){
$filename=date("YmdHis").strval(rand(10000,99999));
return $filename.'.'.$this->fileType;
}

private function setNewFileName(){
if($this->randname){
$this->setOptions("newFileName",$this->fileRandName());
}else{
$this->setOptions("newFileName",$this->sourceName);
}
}

private function setOptions($key,$value){
$this->$key=$value;
}

private function setFiles($name="",$tmp_name="",$size=0,$error=0){
$this->setOptions("errorNum",$error);

if($error){ //When $error<>0 that was true.
return false;
}

$this->setOptions("sourceName",$name);
$this->setOptions("tempName",$tmp_name);
$this->setOptions("fileSize",$size);
$arrStr=explode(".",$name);
$this->setOptions("fileType",strtolower($arrStr[count($arrStr)-1]));

return true;
}

private function copyFile(){
if(!$this->errorNum){ // This situation means $errorNum<>0.
$filepath=rtrim($this->filepath,"/")."/";
$filepath.=$this->newFileName;

if(@move_uploaded_file($this->tempName,$filepath)){
//This has a function to rename a new file name
return true;
}else{
$this->setOptions("errorNum",-3);
}
}else{
return false;
}
}

public function uploadFile($fileField){
if($this->checkFilePath()){ //We should do checkFilePath() at first sub.
}else{
$this->errorMsg=$this->getErrorStr();
return false;
}

$name=$_FILES[$fileField]["name"];
$tmp_name=$_FILES[$fileField]["tmp_name"];
$size=$_FILES[$fileField]["size"];
$error=$_FILES[$fileField]["error"];

$return=true;

if($this->setFiles($name,$tmp_name,$size,$error)){
if($this->checkFileSize() && $this->checkFileType()){
$this->setNewFileName();
if($this->copyFile()){
return true;
}else{
$return=false;
}
}else{
$return=false;
}
}else{
$return=false;
}

if(!$return){
$this->errorMsg=$this->getErrorStr();
}

return true;
}
public function getNewFileName(){
return $this->newFileName;
}
public function getErrorMsg(){
return $this->errorMsg;
}

}

?>