Java p2p client - Tilted Forum Project Discussion Community

AngelicVampire · 09-13-2004, 10:16 AM

Does anyone know any good books or websites with hints, tips or source code for programming a java p2p file sharing client...

Thanks guys.

Pragma · 09-13-2004, 12:47 PM

Well, how much do you know at the moment about TCP/IP programming in Java? How much do you know about threading? Those are some of the most important steps in programming any network app, especially a P2P client.

AngelicVampire · 09-14-2004, 03:05 AM

A little, however I need to learn more. I have looked around bookshops and stuff and have not managed to find a good book on this sort of thing, well there was one however it did not go into much detail on this subject really (or any networking) which seemed odd for a networking book.

Even if you know a c++ or C or even a pseudocode type version of this sort of coding... I really need a little help on this.

crazycousinjim · 09-21-2004, 02:37 AM

Like Pragma said, first and foremostlearn about threading and where the pitfalls are. That aside, what type of P2P app do you want to write ?? Is it with an established protocol ?? How do you plan on searching across your network ?? Those are all very important details you must consider before going out and trying to build the next Napster. Enlighten us to what you are actually trying to do and we might be in a bit better position to assist you.

AngelicVampire · 09-21-2004, 09:29 AM

Basically I want a system similar to emule, basically people can share files by folder or file path (or by indexing their drives for certain file types). The client then maintains a list of the files and an identity number for that file.

The clients when connected will first try their last good servers lists (people they connected to last time) and then a master server with hopefully an up to date list. If that fails it should port scan the entire network for clients (its only about 5000 machines connected at most all with static IP addresses). If it recieves a response from another client both should share their list of linked nodes (to ensure that the network is as stable as possible), and then upload a copy of their shared files (and files that can be seen by that machine) as a searchable list (probably implment a database here) by filename or by code number. Then its a case of trying to acquire the files which would hopefully be done by parts (an offset into the file?) to ensure that downloads are spread over multiple machines.

it is primarily the file transfer section that I need help with as I can find examples of simple chat servers and suchlike however nothing seems to cover sending parts of files and recombining them into a single usable file. If possible I would like to include a feature to stop people freeloading so that the system is balanced and that people must share in order to be shared with.

Hope that is slightly better.

crazycousinjim · 09-21-2004, 11:46 AM

Wow. That is a tall order. For some of those features such as transfer code and file chunk assembly I would browse the BitTorrent code. You could also take a look at these 2 sites

1) http://www.openp2p.com - Part of the whole O'Reilly network. Lots of good articles and examples to look at.

2) Also check out http://www.jxta.org, it is a set of protocols and frameworks for enabling P2P in Java. It has a lot of discovery and low level networking built into it already.

Best of luck, on your adventure, I would seriously bruch up on your basics before diving into some of these technologies too deep.

AngelicVampire · 09-21-2004, 12:14 PM

I could not find a copy of the bittorent source, I looked at the main site and ran a few searches but most turned up bittorent sourceS rather than source code...

thanks for the links... the project is not meant to be that ambitious however I want to use it as a learning experience for other bigger projects, we all have to start somewhere... the question is where...

crazycousinjim · 09-21-2004, 02:24 PM

Here is the latest Bittorrent source. It is python, but python isn't that hard to understand.
http://prdownloads.sourceforge.net/b...2.zip?download

As far as learning, I would say try building some simple network apps. Maybe even start with the tutorials on the jxta page. They are pretty informative and each is broken down into a separate ares. Good luck.

Pragma · 09-22-2004, 05:08 AM

Whether or not you want it to be that ambitious, it is - how much programming experience do you have?

AngelicVampire · 09-22-2004, 07:54 AM

Probably far less than I need... but I am going to work at this project.

09-13-2004, 10:16 AM	#1 (permalink)
AngelicVampire Insane	Java p2p client Does anyone know any good books or websites with hints, tips or source code for programming a java p2p file sharing client... Thanks guys.

09-13-2004, 12:47 PM	#2 (permalink)
Pragma I am Winter Born Location: Alexandria, VA	Well, how much do you know at the moment about TCP/IP programming in Java? How much do you know about threading? Those are some of the most important steps in programming any network app, especially a P2P client.

09-14-2004, 03:05 AM	#3 (permalink)
AngelicVampire Insane	A little, however I need to learn more. I have looked around bookshops and stuff and have not managed to find a good book on this sort of thing, well there was one however it did not go into much detail on this subject really (or any networking) which seemed odd for a networking book. Even if you know a c++ or C or even a pseudocode type version of this sort of coding... I really need a little help on this.

09-21-2004, 02:37 AM	#4 (permalink)
crazycousinjim Crazy Location: Copenhagen, Denmark	Like Pragma said, first and foremostlearn about threading and where the pitfalls are. That aside, what type of P2P app do you want to write ?? Is it with an established protocol ?? How do you plan on searching across your network ?? Those are all very important details you must consider before going out and trying to build the next Napster. Enlighten us to what you are actually trying to do and we might be in a bit better position to assist you.

09-21-2004, 09:29 AM	#5 (permalink)
AngelicVampire Insane	Basically I want a system similar to emule, basically people can share files by folder or file path (or by indexing their drives for certain file types). The client then maintains a list of the files and an identity number for that file. The clients when connected will first try their last good servers lists (people they connected to last time) and then a master server with hopefully an up to date list. If that fails it should port scan the entire network for clients (its only about 5000 machines connected at most all with static IP addresses). If it recieves a response from another client both should share their list of linked nodes (to ensure that the network is as stable as possible), and then upload a copy of their shared files (and files that can be seen by that machine) as a searchable list (probably implment a database here) by filename or by code number. Then its a case of trying to acquire the files which would hopefully be done by parts (an offset into the file?) to ensure that downloads are spread over multiple machines. it is primarily the file transfer section that I need help with as I can find examples of simple chat servers and suchlike however nothing seems to cover sending parts of files and recombining them into a single usable file. If possible I would like to include a feature to stop people freeloading so that the system is balanced and that people must share in order to be shared with. Hope that is slightly better.

09-21-2004, 11:46 AM	#6 (permalink)
crazycousinjim Crazy Location: Copenhagen, Denmark	Wow. That is a tall order. For some of those features such as transfer code and file chunk assembly I would browse the BitTorrent code. You could also take a look at these 2 sites 1) http://www.openp2p.com - Part of the whole O'Reilly network. Lots of good articles and examples to look at. 2) Also check out http://www.jxta.org, it is a set of protocols and frameworks for enabling P2P in Java. It has a lot of discovery and low level networking built into it already. Best of luck, on your adventure, I would seriously bruch up on your basics before diving into some of these technologies too deep.

09-21-2004, 12:14 PM	#7 (permalink)
AngelicVampire Insane	I could not find a copy of the bittorent source, I looked at the main site and ran a few searches but most turned up bittorent sourceS rather than source code... thanks for the links... the project is not meant to be that ambitious however I want to use it as a learning experience for other bigger projects, we all have to start somewhere... the question is where...

09-21-2004, 02:24 PM	#8 (permalink)
crazycousinjim Crazy Location: Copenhagen, Denmark	Here is the latest Bittorrent source. It is python, but python isn't that hard to understand. http://prdownloads.sourceforge.net/b...2.zip?download As far as learning, I would say try building some simple network apps. Maybe even start with the tutorials on the jxta page. They are pretty informative and each is broken down into a separate ares. Good luck.

09-22-2004, 05:08 AM	#9 (permalink)
Pragma I am Winter Born Location: Alexandria, VA	Whether or not you want it to be that ambitious, it is - how much programming experience do you have?

09-22-2004, 07:54 AM	#10 (permalink)
AngelicVampire Insane	Probably far less than I need... but I am going to work at this project.