[ANNOUNCE] BitCoinJ v0.1, a client-mode implementation in Java

[Mike Hearn]

Yes, that is supposed to work. I haven't tested it though. John Sample has been doing some work on the networking layer and supporting multiple simultaneous peers.

Right now it's not that useful to talk to multiple peers, at least not for Android clients which is what I'm working towards. The connect/sync/disconnect model works much better. In future it'll be helpful for other stuff but there needs to be some protocol extensions first (eg finding the lowest latency peer, probing the memory pool etc).

BitCoinJ is still a building site. Be aware lots will change, in particular the wallet format and APIs will still change a fair bit. I need to do more work on block chain re-orgs as there are a few unusual cases that aren't really handled today like a reorg causing a pending tx to become invalidated by a double spend. After that I'll probably do a 0.2 release.

[BitterTea]

Cool, I appreciate the work you're doing. I'm not doing anything critical, just want to play around with some ideas for Bitcoin related projects. I figured going from C# to Java would be easier than C# to C++.

[just_someguy]

I figured going from C# to Java would be easier than C# to C++.

It is. Just jump in. I don't think [mike] is a full time Java coder either though you wouldn't know it.
Think of Java as C# without all the nifty stuff. When approaching a problem figure out how you'd do it without lambdas, function pointers, events, properties, valued enums, value type strings, etc. You just have objects and functions.
Then remember never to test string equality with ==, always .equals().
Now you know Java. Get cracking!

[bitcool]

I figured going from C# to Java would be easier than C# to C++.

Think of Java as C# without all the nifty stuff. When approaching a problem figure out how you'd do it without lambdas, function pointers, events, properties, valued enums, value type strings, etc. You just have objects and functions.
Then remember never to test string equality with ==, always .equals().

Now I understand why Bill has more money than Larry.

[jimbobway]

In terms of scalability, could a two-tier system be developed where super users would run the main bitcoin client that would store and verify the block chain and on the second tier normal users would use a lesser version of the client such as BitCoinJ (that does not store the block chain and is only used for verification of payments?)

If bitcoin goes mainstream and takes as many transactions as Visa (thousands per second) then would Bitcoin(supernode)/BitcoinJ(node) be a solution?  Not everyone can afford racks of computers...

[Mike Hearn]

Yes indeed. See:

http://bitcointalk.org/index.php?topic=7972.0