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How to write your own BitTorrent client in Java by using Bt library

dis-sys 8y ago
I did that more than 10 years ago using libtorrent. In 2018, an article on how to write a bittorrent client using an existing library is not that cool any more.
- deleted 8y ago
  [deleted]
- atomashpolskiy 8y ago
  It's not supposed to be cool, just normal boring software that does useful things. As the author, I'm amazed by the number of people that contact me and ask questions on integrating Bt into their Java/Scala software which some of us use daily. In 2018 Bt is the most feature-complete BitTorrent implementation that is 100% pure Java.
  - zerr 8y ago
    Waiting for "how to write bittorrent library" series ;)
  - dis-sys 8y ago
    What I am trying to point out is that bittorrent is a well established protocol with a long list of client implementations[1]. 17 years[2] after the release of its original client in python, a particular library implementing the exact same protocol in a specific language is not a "news" - when this site is called "Hacker News". In 2018, when it comes to bittorrent, I'd expect to see _real_ news/discussions, just a few examples on top of my head - 1. recent large scale measurement results, e.g. how many concurrent users in 2018, how many are using the selfish-and-trouble-making Xunlei, mobile usage, etc. 2. any sybil attack recently observed in its DHT? progress on sybil attack detection and prevention. 3. frameworks for scraping contents on bittorrent 4. recent progress on NAT traversal [1] https://en.wikipedia.org/wiki/Comparison_of_BitTorrent_clients https://en.wikipedia.org/wiki/Comparison_of_BitTorrent_clien... [2] https://en.wikipedia.org/wiki/BitTorrent_(software) https://en.wikipedia.org/wiki/BitTorrent_(software)
    - detaro 8y ago
      You've been here for over a year, shouldn't that be enough time to look at the rules once or otherwise realize Hacker News is not strictly for "news", and indeed the definition of good content for HN doesn't even mention news or new-ness? You want to see content covering new developments for Bittorrent? Submit it instead of complaining that others content isn't revolutionary enough.
    - grzm 8y ago
      Hacker News is a bit of a misnomer. The guidelines are clear as to what's appropriate to submit: > "On-Topic: Anything that good hackers would find interesting. That includes more than hacking and startups. If you had to reduce it to a sentence, the answer might be: anything that gratifies one's intellectual curiosity." https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html It need not be new or news.
    - atomashpolskiy 8y ago
      The first link contains a list of 3 (three) libraries. I personally would not call that "long". Anyways, your opinion is much appreciated, I'll make sure to check with you next time I decide to post something on HN.
- lolptdr 8y ago
  Just because you may have experience doing it doesn't mean other people may know about it. And just because it's not new doesn't mean it's not cool. The upvote-only scheme of HN will speak for itself so you shouldn't care so much.
atomashpolskiy 8y ago
Github: https://github.com/atomashpolskiy/bt https://github.com/atomashpolskiy/bt
ryanlol 8y ago
"How to write your own HTTP client using curl" is the vibe I get from this. The library is the client here, the blog post is just about building an UI for it.
- atomashpolskiy 8y ago
  In fact there is only one short paragraph about the UI, and the rest of the article tells about the design, API and possible use cases. Not exactly like curl(1) man page, but also definitely not like what you say.
  - ryanlol 8y ago
    The title is “How to write your own BitTorrent client in Java by using Bt library” The article says nothing about building a bittorrent client, it talks about interfacing with a library which implements a bittorrent client API.
    - detaro 8y ago
      > it talks about interfacing with a library which implements a bittorrent client API Which is a valid way of building a piece of software commonly called a "bittorrent client". HTTP client isn't used in the same way, but "building a download manager using curl" would be a fair comparison.
    - atomashpolskiy 8y ago
      May I ask you, what did you expect?
MichailP 8y ago
Is this possible without using any (torrent specific) library?
- consto 8y ago
  How do you think Bt or libbittorent was written?
  - MichailP 8y ago
    I was thinking about this kind of DIY short term effort to have an example of torrent functionality. Not collaborative development of a torrent library for 10 years.
- matheusmoreira 8y ago
  Of course. You can read the protocol specification and/or study the source code of the existing libraries and clients to figure out how they work. I think a reasonable first step is learning about B-encoding so that you can parse and generate torrent files.
- war1025 8y ago
  Here is a bit torrent client I wrote back when I was in school. https://github.com/war1025/Torrent https://github.com/war1025/Torrent
m00dy 8y ago
Why would we write a special client ? I can spawn a cli tool and do it for me what I want
- atomashpolskiy 8y ago
  What if your software is supposed to work on multiple platforms or be self-contained? It's not targeted for personal use (at least that case is not the priority)
amelius 8y ago
I'm personally more excited about torrent libraries that run inside webbrowsers. E.g. https://github.com/webtorrent/webtorrent https://github.com/webtorrent/webtorrent

I did that more than 10 years ago using libtorrent. In 2018, an article on how to write a bittorrent client using an existing library is not that cool any more.

deleted 8y ago
[deleted]
atomashpolskiy 8y ago
It's not supposed to be cool, just normal boring software that does useful things. As the author, I'm amazed by the number of people that contact me and ask questions on integrating Bt into their Java/Scala software which some of us use daily. In 2018 Bt is the most feature-complete BitTorrent implementation that is 100% pure Java.
- zerr 8y ago
  Waiting for "how to write bittorrent library" series ;)
- dis-sys 8y ago
  What I am trying to point out is that bittorrent is a well established protocol with a long list of client implementations[1]. 17 years[2] after the release of its original client in python, a particular library implementing the exact same protocol in a specific language is not a "news" - when this site is called "Hacker News". In 2018, when it comes to bittorrent, I'd expect to see _real_ news/discussions, just a few examples on top of my head - 1. recent large scale measurement results, e.g. how many concurrent users in 2018, how many are using the selfish-and-trouble-making Xunlei, mobile usage, etc. 2. any sybil attack recently observed in its DHT? progress on sybil attack detection and prevention. 3. frameworks for scraping contents on bittorrent 4. recent progress on NAT traversal [1] https://en.wikipedia.org/wiki/Comparison_of_BitTorrent_clients https://en.wikipedia.org/wiki/Comparison_of_BitTorrent_clien... [2] https://en.wikipedia.org/wiki/BitTorrent_(software) https://en.wikipedia.org/wiki/BitTorrent_(software)
  - detaro 8y ago
    You've been here for over a year, shouldn't that be enough time to look at the rules once or otherwise realize Hacker News is not strictly for "news", and indeed the definition of good content for HN doesn't even mention news or new-ness? You want to see content covering new developments for Bittorrent? Submit it instead of complaining that others content isn't revolutionary enough.
  - grzm 8y ago
    Hacker News is a bit of a misnomer. The guidelines are clear as to what's appropriate to submit: > "On-Topic: Anything that good hackers would find interesting. That includes more than hacking and startups. If you had to reduce it to a sentence, the answer might be: anything that gratifies one's intellectual curiosity." https://news.ycombinator.com/newsguidelines.html https://news.ycombinator.com/newsguidelines.html It need not be new or news.
  - atomashpolskiy 8y ago
    The first link contains a list of 3 (three) libraries. I personally would not call that "long". Anyways, your opinion is much appreciated, I'll make sure to check with you next time I decide to post something on HN.
lolptdr 8y ago
Just because you may have experience doing it doesn't mean other people may know about it. And just because it's not new doesn't mean it's not cool. The upvote-only scheme of HN will speak for itself so you shouldn't care so much.

atomashpolskiy 8y ago

Github: https://github.com/atomashpolskiy/bt https://github.com/atomashpolskiy/bt

ryanlol 8y ago

"How to write your own HTTP client using curl" is the vibe I get from this. The library is the client here, the blog post is just about building an UI for it.

atomashpolskiy 8y ago
In fact there is only one short paragraph about the UI, and the rest of the article tells about the design, API and possible use cases. Not exactly like curl(1) man page, but also definitely not like what you say.
- ryanlol 8y ago
  The title is “How to write your own BitTorrent client in Java by using Bt library” The article says nothing about building a bittorrent client, it talks about interfacing with a library which implements a bittorrent client API.
  - detaro 8y ago
    > it talks about interfacing with a library which implements a bittorrent client API Which is a valid way of building a piece of software commonly called a "bittorrent client". HTTP client isn't used in the same way, but "building a download manager using curl" would be a fair comparison.
  - atomashpolskiy 8y ago
    May I ask you, what did you expect?

MichailP 8y ago

Is this possible without using any (torrent specific) library?

consto 8y ago
How do you think Bt or libbittorent was written?
- MichailP 8y ago
  I was thinking about this kind of DIY short term effort to have an example of torrent functionality. Not collaborative development of a torrent library for 10 years.
matheusmoreira 8y ago
Of course. You can read the protocol specification and/or study the source code of the existing libraries and clients to figure out how they work. I think a reasonable first step is learning about B-encoding so that you can parse and generate torrent files.
war1025 8y ago
Here is a bit torrent client I wrote back when I was in school. https://github.com/war1025/Torrent https://github.com/war1025/Torrent

m00dy 8y ago

Why would we write a special client ? I can spawn a cli tool and do it for me what I want

atomashpolskiy 8y ago
What if your software is supposed to work on multiple platforms or be self-contained? It's not targeted for personal use (at least that case is not the priority)

amelius 8y ago

I'm personally more excited about torrent libraries that run inside webbrowsers. E.g. https://github.com/webtorrent/webtorrent https://github.com/webtorrent/webtorrent