Welcome to bitcoinj.cash

The bitcoinj.cash library is a Java implementation of the Bitcoin cash protocol. This library is a fork of Mike Hearn's original bitcoinj library aimed at supporting the Bitcoin cash eco-system.

It allows maintaining a wallet and sending/receiving transactions without needing a full blockchain node. It comes with full documentation and some example apps showing how to use it.

For support and discussion please join us on the mailing list.

Release notes are here.

Technologies

• Java 7 for the core modules, Java 8 for everything else (also compiles and runs under JRE/JDK 11 or 12)
• Maven 3+ - for building the project
• Google Protocol Buffers - for use with serialization and hardware communications

Getting started

To get started, it is best to have the latest JDK and Maven installed.

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 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.

If using JDK 11 or above, the WalletTemplate demo you will JavaFX-SDK installed and referenced seperately. In IntelliJ, add javafx-lib path to File > Project Structure > Libraries. Under Run > Edit Configurations, add '--module-path "PATH_TO_FX" --add-modules=javafx.controls,javafx.fxml' to VM options. Replace PATH_TO_FX with javafx lib path, leaving the quotations.

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.

  cd examples
  mvn exec:java -Dexec.mainClass=org.bitcoinj.examples.ForwardingService -Dexec.args="<insert a bitcoin address here>"

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.

Contributing to Bitcoinj Cash

Contributions to Bitcoinj Cash are welcome and encouraged.