php实现大文件断点续传下载实例，看完你就知道超过100M以上的大文件如何断点传输了，这个功能还是比较经典实用的，毕竟大文件上传功能经常用得到。
require_once('download.class.php'); date_default_timezone_set('Asia/Shanghai'); error_reporting(E_STRICT); function errorHandler($errno, $errstr, $errfile, $errline) { echo '<p>error:', $errstr, '</p>'; exit(); } set_error_handler('errorHandler'); define('IS_DEBUG', true); $filePath = 'test.zip'; $mimeType = 'audio/x-matroska'; $range = isset($_SERVER['HTTP_RANGE']) ? $_SERVER['HTTP_RANGE'] : null; if (IS_DEBUG) { // $range = "bytes=1000-1999\n2000"; // $range = "bytes=1000-1999,2000"; // $range = "bytes=1000-1999,-2000"; // $range = "bytes=1000-1999,2000-2999"; } set_time_limit(0); $transfer = new Transfer($filePath, $mimeType, $range); if (IS_DEBUG) { $transfer->setIsLog(true); } $transfer->send();download.class.php
/** * 文件传输，支持断点续传。 * 2g以上超大文件也有效 * @author MoXie */ class Transfer { /** * 缓冲单元 */ const BUFF_SIZE = 5120; // 1024 * 5 /** * 文件地址 * @var <String> */ private $filePath; /** * 文件大小 * @var <String> Php超大数字 字符串形式描述 */ private $fileSize; /** * 文件类型 * @var <String> */ private $mimeType; /** * 请求区域（范围） * @var <String> */ private $range; /** * 是否写入日志 * @var <Boolean> */ private $isLog = false; /** * * @param <String> $filePath 文件路径 * @param <String> $mimeType 文件类型 * @param <String> $range 请求区域（范围） */ function __construct($filePath, $mimeType = null, $range = null) { $this->filePath = $filePath; $this->fileSize = sprintf('%u', filesize($filePath)); $this->mimeType = ($mimeType != null) ? $mimeType : "application/octet-stream"; // bin $this->range = trim($range); } /** * 获取文件区域 * @return <Map> {'start':long,'end':long} or null */ private function getRange() { /** * Range: bytes=-128 * Range: bytes=-128 * Range: bytes=28-175,382-399,510-541,644-744,977-980 * Range: bytes=28-175\n380 * type 1 * RANGE: bytes=1000-9999 * RANGE: bytes=2000-9999 * type 2 * RANGE: bytes=1000-1999 * RANGE: bytes=2000-2999 * RANGE: bytes=3000-3999 */ if (!empty($this->range)) { $range = preg_replace('/[\s|,].*/', '', $this->range); $range = explode('-', substr($range, 6)); if (count($range) < 2) { $range[1] = $this->fileSize; // Range: bytes=-100 } $range = array_combine(array('start', 'end'), $range); if (empty($range['start'])) { $range['start'] = 0; } if (!isset($range['end']) || empty($range['end'])) { $range['end'] = $this->fileSize; } return $range; } return null; } /** * 向客户端发送文件 */ public function send() { $fileHande = fopen($this->filePath, 'rb'); if ($fileHande) { // setting ob_end_clean(); // clean cache ob_start(); ini_set('output_buffering', 'Off'); ini_set('zlib.output_compression', 'Off'); $magicQuotes = get_magic_quotes_gpc(); // set_magic_quotes_runtime(0); // init $lastModified = gmdate('D, d M Y H:i:s', filemtime($this->filePath)) . ' GMT'; $etag = sprintf('w/"%s:%s"', md5($lastModified), $this->fileSize); $ranges = $this->getRange(); // headers header(sprintf('Last-Modified: %s', $lastModified)); header(sprintf('ETag: %s', $etag)); header(sprintf('Content-Type: %s', $this->mimeType)); $disposition = 'attachment'; if (strpos($this->mimeType, 'image/') !== FALSE) { $disposition = 'inline'; } header(sprintf('Content-Disposition: %s; filename="%s"', $disposition, basename($this->filePath))); if ($ranges != null) { if ($this->isLog) { $this->log(json_encode($ranges) . ' ' . $_SERVER['HTTP_RANGE']); } header('HTTP/1.1 206 Partial Content'); header('Accept-Ranges: bytes'); header(sprintf('Content-Length: %u', $ranges['end'] - $ranges['start'])); header(sprintf('Content-Range: bytes %s-%s/%s', $ranges['start'], $ranges['end'], $this->fileSize)); // fseek($fileHande, sprintf('%u', $ranges['start'])); } else { header("HTTP/1.1 200 OK"); header(sprintf('Content-Length: %s', $this->fileSize)); } // read file $lastSize = 0; while (!feof($fileHande) && !connection_aborted()) { $lastSize = sprintf("%u", bcsub($this->fileSize, sprintf("%u", ftell($fileHande)))); if (bccomp($lastSize, self::BUFF_SIZE) > 0) { $lastSize = self::BUFF_SIZE; } echo fread($fileHande, $lastSize); ob_flush(); flush(); } set_magic_quotes_runtime($magicQuotes); ob_end_flush(); } if ($fileHande != null) { fclose($fileHande); } } /** * 设置记录 * @param <Boolean> $isLog 是否记录 */ public function setIsLog($isLog = true) { $this->isLog = $isLog; } /** * 记录 * @param <String> $msg 记录信息 */ private function log($msg) { try { $handle = fopen('transfer_log.txt', 'a'); fwrite($handle, sprintf('%s : %s' . PHP_EOL, date('Y-m-d H:i:s'), $msg)); fclose($handle); } catch (Exception $e) { // null; } } }这样就实现了大文件断点下载功能了，有兴趣的朋友可以学起来！