php can't open pdf after downloading - php

Question

in my project I need to upload pdf file and download it afterwards.
everything works fine , but after i download the pdf file its been currupted and i can't view it.
if i try to open it with Adobe Acrobat Reader i get this error that says the file been currupted and didn't encoded correctly.
can someone help me to resolve this? thanks!
php script for download and upload:
<?php
// connect to the database
require_once 'connectionoop.php';
require_once 'core/init.php';
$query1 = sprintf("SELECT files.id, files.name,files.size ,files.downloads , association.Aname ,projects.Pname,files.project
FROM files
INNER JOIN projects ON files.project = projects.id INNER JOIN association ON projects.Aid = association.id
");
$result1 = $mysqli->query($query1);
$files=array();
foreach ($result1 as $row) {
$files[] = $row;
}
// Uploads files
if (isset($_POST['save'])) { // if save button on the form is clicked
// name of the uploaded file
$filename = $_FILES['myfile']['name'];
$proj = $_POST['Aid'];
// destination of the file on the server
$destination = 'uploads/' . $filename;
// get the file extension
$extension = pathinfo($filename, PATHINFO_EXTENSION);
// the physical file on a temporary uploads directory on the server
$file = $_FILES['myfile']['tmp_name'];
$size = $_FILES['myfile']['size'];
if (!in_array($extension, ['zip', 'pdf', 'docx'])) {
echo "You file extension must be .zip, .pdf or .docx";
} elseif ($_FILES['myfile']['size'] > 1000000) { // file shouldn't be larger than 1Megabyte
echo "File too large!";
} else {
// move the uploaded (temporary) file to the specified destination
if (copy($file, $destination)) {
$query = sprintf("INSERT INTO files (name, size, downloads , project) VALUES ('$filename', $size, 0,$proj)");
//execute query
$result = $mysqli->query($query);
$sql = "INSERT INTO files (name, size, downloads) VALUES ('$filename', $size, 0)";
$pr=new Project($proj);
$pr->update(array(
'hasfile' =>1
));
Redirect::to('downloads.php');
} else {
echo "Failed to upload file.<br>".$destination;
}
}
}
if (isset($_GET['file_id'])) {
$id = $_GET['file_id'];
$query2 = sprintf("SELECT * FROM files WHERE id=$id");
// fetch file to download from database
$result2 = $mysqli->query($query2);
$data = array();
foreach ($result2 as $row) {
$data[] = $row;
}
$filepath = 'uploads/' .$data[0]['name'];
if (file_exists($filepath)) {
header('Content-Description: File Transfer');
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename=' . basename($filepath));
header('Expires: 0');
header('Cache-Control: must-revalidate');
header('Pragma: public');
header('Content-Length: ' . filesize('uploads/' . $data['name']));
readfile('uploads/' . $data['name']);
// Now update downloads count
$newCount = $data['downloads'] + 1;
$query3 = sprintf("UPDATE files SET downloads=$newCount WHERE id=$id");
// fetch file to download from database
$result3 = $mysqli->query($query3);
exit;
}
}

Answer 1

It should be header("Content-type:application/pdf");