Enable the custom connection for file download to support resumable multi-thread link download of flashget! JSP/Servlet implementation!

<%
/*
The file name can be saved as: Download. jsp
For HTTP requests and responses, you can use flashget to download http: // connection process monitoring:
The blue part is: client request
Purple: Server Response
:
Http://blog.csdn.net/images/blog_csdn_net/playyuer/30110/o_FlashGet.gif
For more information, see the following flashget session List:

*/
// You can use the file on your server and its path
String S = "I: // setupres // sun // j2re-1_4_2_05-windows-i586-p.exe ";
// String S = "E: // tree. mdb ";

// Randomaccessfile can also be implemented after testing. If you are interested, remove the annotation and comment out the fileinputstream statement.
// Java. Io. randomaccessfile RAF = new java. Io. randomaccessfile (S, "R ");

Java. Io. File F = new java. Io. file (s );
Java. Io. fileinputstream FCM = new java. Io. fileinputstream (f );

Response. Reset ();

Response. setheader ("server", "playyuer@Microshaoft.com ");

// Tell the client to allow multi‑thread download of resumable Data Transfer
// The response format is:
// Accept-ranges: bytes
Response. setheader ("Accept-ranges", "bytes ");

Long p = 0;
Long L = 0;
// L = Raf. Length ();
L = f. Length ();

// If resumable data transfer is not enabled for the first time, the status is 200 by default, and no explicit settings are required.
// The response format is:
// HTTP/1.1 200 OK

If (request. getheader ("range ")! = NULL) // start byte of the file block requested by the client
{
// If the range of the downloaded file is not all, declare to the client to support and start file block download
// Set the status
// The response format is:
// HTTP/1.1 206 partial content
Response. setstatus (javax. servlet. http. httpservletresponse. SC _partial_content); // 206

// Get the starting byte from the request
// The request format is:
// Range: bytes = [start byte of the file block]-
P = long. parselong (request. getheader ("range"). replaceall ("bytes =", ""). replaceall ("-",""));
}

// The length of the downloaded file (or block)
// The response format is:
// Content-Length: [total file size]-[start byte of the downloaded file block requested by the client]
Response. setheader ("Content-Length", new long (L-P). tostring ());

If (P! = 0)
{
// Not the first download,
// The response format is:
// Content-range: bytes [start byte of the file block]-[total file size-1]/[total file size]
Response. setheader ("content-range", "bytes" + new long (P ). tostring () + "-" + new long (L-1 ). tostring () + "/" + new long (l ). tostring ());
}

// Response. setheader ("connection", "close"); // if this sentence exists, ie cannot be used for direct download.

// Make the client download directly
// The response format is:
// Content-Type: Application/octet-stream
Response. setcontenttype ("application/octet-stream ");

// Specify the default download file name for the client download
// The response format is:
// Content-Disposition: attachment; filename = "[file name]"
// Response. setheader ("content-disposition", "attachment; filename =/" "+ S. substring (S. lastindexof ("//") + 1) + "/"); // The randomaccessfile can also be tested. If you are interested, remove the annotation and comment out the fileinputstream statement.
Response. setheader ("content-disposition", "attachment; filename =/" "+ F. getname () + "/"");

// Raf. Seek (P );
FS. Skip (P );

Byte [] B = new byte [1024];
Int I;

// While (I = Raf. Read (B ))! =-1) // tested randomaccessfile can also be implemented. If you are interested, remove the annotation and comment out the fileinputstream statement.
While (I = Fi. Read (B ))! =-1)
{
Response. getoutputstream (). Write (B, 0, I );
}
// Raf. Close (); // The randomaccessfile can also be tested. If you are interested, remove the annotation and comment out the fileinputstream statement.
FCM. Close ();
%>

========================================================== ========================================

In flashget
A set of first direct downloads without resumable http session processes:
client requests:
Mon Aug 02 05:46:36 2004 connection download2.flashfxp.com: 80
Mon Aug 02 05:46:36 2004 connection download2.flashfxp.com [IP = 66.98.228.125: 80]
Mon Aug 02 05:46:37 2004 connected.
Mon Aug 02 05:46:37 2004 get/zip/flashfxp_30_setup.exe HTTP/1.1
Mon Aug 02 05:46:37 2004 HOST: download2.flashfxp.com
Mon Aug 02 05:46:37 2004 accept: */*
Mon Aug 02 05:46:37 2004 Referer: http://playyuer.microshaoft.com
Mon Aug 02 05:46:37 2004 User-Agent: Mozilla/4.0 (compatible; MSIE 5.00; Windows 98)
Mon Aug 02 05:46:37 2004 Pragma: No-Cache
Mon Aug 02 05:46:37 2004 cache-control: No-Cache
Mon Aug 02 05:46:37 2004 authorization: basic mgrhetpjy2zfzg93bmxvywq =
Mon Aug 02 05:46:37 2004 connection: Close

Server Response:
Mon Aug 02 05:46:37 2004 HTTP/1.1 200 OK
Mon Aug 02 05:46:37 2004 date: Sun, 01 Aug 2004 21:46:29 GMT
Mon Aug 02 05:46:37 2004 server: Apache/1.3.27 (UNIX) (red-hat/Linux) mod_fastcgi/2.2.12 mod_gzip/1.3.19.1a mod_jk/1.2.0 mod_perl/1.26 PHP/4.3.3 FrontPage/5.0.2 mod_ssl/2.8.12 OpenSSL/0.9.6b
Mon Aug 02 05:46:37 2004 last-modified: Fri, 30 Jul 2004 18:41:18 GMT
Mon Aug 02 05:46:37 2004 etag: "4f80fa-1ecf20-450a964e"
Mon Aug 02 05:46:37 2004 accept-ranges: bytes
Mon Aug 02 05:46:37 2004 Content-Length: 2019104
Mon Aug 02 05:46:37 2004 connection: Close
Mon Aug 02 05:46:37 2004 Content-Type: Application/octet-stream

 

HTTP session process for resumable data transfer:
client request:
Mon Aug 02 05:27:05 2004 is connecting download2.flashfxp.com: 80
Mon Aug 02 05:27:05 2004 is connecting download2.flashfxp.com [IP = 66.98.228.125: 80]
Mon Aug 02 05:27:05 2004 connected.
Mon Aug 02 05:27:05 2004 get/zip/flashfxp_30_setup.exe HTTP/1.1
Mon Aug 02 05:27:05 2004 HOST: download2.flashfxp.com
Mon Aug 02 05:27:05 2004 accept: */*
Mon Aug 02 05:27:05 2004 Referer: http://playyuer.microshaoft.com
Mon Aug 02 05:27:05 2004 User-Agent: Mozilla/4.0 (compatible; MSIE 5.00; Windows 98)
Mon Aug 02 05:27:05 2004 range: bytes = 191621-
Mon Aug 02 05:27:05 2004 Pragma: No-Cache
Mon Aug 02 05:27:05 2004 cache-control: no-Cache
Mon Aug 02 05:27:05 2004 authorization: Basic mgrhetpjy2zfzg93bmxvywq =
Mon Aug 02 05:27:05 2004 connection: Close

Server Response:
Mon Aug 02 05:27:06 2004 HTTP/1.1 206 partial content
Mon Aug 02 05:27:06 2004 date: Sun, 01 Aug 2004 21:26:57 GMT
Mon Aug 02 05:27:06 2004 server: Apache/1.3.27 (UNIX) (red-hat/Linux) mod_fastcgi/2.2.12 mod_gzip/1.3.19.1a mod_jk/1.2.0 mod_perl/1.26 PHP/4.3.3 FrontPage/5.0.2 mod_ssl/2.8.12 OpenSSL/0.9.6b
Mon Aug 02 05:27:06 2004 last-modified: Fri, 30 Jul 2004 18:41:18 GMT
Mon Aug 02 05:27:06 2004 etag: "4f80fa-1ecf20-450a964e"
Mon Aug 02 05:27:06 2004 accept-ranges: bytes
Mon Aug 02 05:27:06 2004 Content-Length: 1827483
Mon Aug 02 05:27:06 2004 content-range: bytes 191621-2019103/2019104
Mon Aug 02 05:27:06 2004 connection: Close
Mon Aug 02 05:27:06 2004 Content-Type: Application/octet-stream