既然涉及到PHP开发APP接口，文件上传和下载是在所难免的，也许有些人会考虑第三方的，比如七牛，但是学习和使用终究还是要会的，所以，所以……
文件上传下载实战
以前一直在做iOS，最近转行去搞php开发，总觉得力不从心。这几天有个需求，是关于php的文件上传和下载的。给大家分享下自己的学习资料。
1.先来个请求页面upload.html
<html>
<head>
<title>Administration - upload new files</title>
</head>
<body>
<h1>Upload new news files</h1>
<form enctype="multipart/form-data" action="upload.php" method=post>
<input type="hidden" name="MAX_FILE_SIZE" value="1000000">
Upload this file: <input name="userfile" type="file">
<input type="submit" value="Send File">
</form>
</body>
</html>
2.php处理客户端请求的数据upload.html
<html>
<head>
<title>Uploading...</title>
</head>
<body>
<h1>Uploading file...</h1>
<?php
//Check to see if an error code was generated on the upload attempt
if ($_FILES['userfile']['error'] > 0)
{
echo 'Problem: ';
switch ($_FILES['userfile']['error'])
{
case 1: echo 'File exceeded upload_max_filesize';
break;
case 2: echo 'File exceeded max_file_size';
break;
case 3: echo 'File only partially uploaded';
break;
case 4: echo 'No file uploaded';
break;
case 6: echo 'Cannot upload file: No temp directory specified.';
break;
case 7: echo 'Upload failed: Cannot write to disk.';
break;
}
exit;
}
// Does the file have the right MIME type?
if ($_FILES['userfile']['type'] != 'text/plain')
{
echo 'Problem: file is not plain text';
exit;
}
// put the file where we'd like it
$upfile = '/uploads/'.$_FILES['userfile']['name'];
if (is_uploaded_file($_FILES['userfile']['tmp_name']))
{
if (!move_uploaded_file($_FILES['userfile']['tmp_name'], $upfile))
{
echo 'Problem: Could not move file to destination directory';
exit;
}
}
else
{
echo 'Problem: Possible file upload attack. Filename: ';
echo $_FILES['userfile']['name'];
exit;
}
echo 'File uploaded successfully<br><br>';
// reformat the file contents
$fp = fopen($upfile, 'r');
$contents = fread ($fp, filesize ($upfile));
fclose ($fp);
$contents = strip_tags($contents);
$fp = fopen($upfile, 'w');
fwrite($fp, $contents);
fclose($fp);
// show what was uploaded
echo 'Preview of uploaded file contents:<br><hr>';
echo $contents;
echo '<br><hr>';
?>
</body>
</html>
3.php文件下载
<?php
$filePath = "template/";//此处给出你下载的文件在服务器的什么地方
$fileName = "template.xls";
//此处给出你下载的文件名
$file = fopen($filePath . $fileName, "r"); // 打开文件
//输入文件标签
Header("Content-type:application/octet-stream ");
Header("Accept-Ranges:bytes ");
Header("Accept-Length: " . filesize($filePath . $fileName));
Header("Content-Disposition: attachment; filename= " . $fileName);
// 输出文件内容
echo fread($file, filesize($filePath . $fileName));
fclose($file);
exit;
?>
总的来说，上面的3个代码段只是简单介绍了php文件的上传下载，还有很多问题要解决，就例如上传大文件的时候怎么处理，批量上传、大文件下载等等问题。当然跟java一样，php也有很多框架可以解决这方面。
