The bitcoinj library is a Java implementation of the Bitcoin protocol, which allows it to maintain a wallet and send/receive transactions without needing a local copy of Bitcoin Core. It comes with full documentation and some example apps showing how to use it.
* [Maven 3+](http://maven.apache.org) - for building the project
* [Orchid](https://github.com/subgraph/Orchid) - for secure communications over [TOR](https://www.torproject.org)
* [Google Protocol Buffers](https://code.google.com/p/protobuf/) - for use with serialization and hardware communications
### Getting started
To get started, it is best to have the latest JDK and Maven installed. The HEAD of the `master` branch contains the latest development code and various production releases are provided on feature branches.
#### Building from the command line
To perform a full build use
```
mvn clean package
```
You can also run
```
mvn site:site
```
to generate a website with useful information like JavaDocs.
The outputs are under the `target` directory.
#### Building from an IDE
Alternatively, just import the project using your IDE. [IntelliJ](http://www.jetbrains.com/idea/download/) has Maven integration built-in and has a free Community Edition. Simply use `File | Import Project` and locate the `pom.xml` in the root of the cloned project source tree.
### Example applications
These are found in the `examples` module.
#### Forwarding service
This will download the block chain and eventually print a Bitcoin address that it has generated.
If you send coins to that address, it will forward them on to the address you specified.
Note that this example app *does not use checkpointing*, so the initial chain sync will be pretty slow. You can make an app that starts up and does the initial sync much faster by including a checkpoints file; see the documentation for
more info on this technique.
### Where next?
Now you are ready to [follow the tutorial](https://bitcoinj.github.io/getting-started).
