Welcome to bitcoinsvj

The bitcoinsvj library is a Java implementation of the Bitcoin (BSV) protocol. This library is a fork of pokkst's bitcoincashj library aimed at supporting the Bitcoin SV eco-system.

• 2GB block support
• Standard BIP44 derivation (m/44'/145'/0' for BSV)
• UTXO management when sending coins using SendRequest.utxos
• BIP47 Reusable Payment Codes support
• Up-to-date hardfork checkpoints

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.

Technologies

• Java 7+ and Gradle 4.4+ for the core module
• Java 8+ and Gradle 4.4+ for tools and examples
• Java 11+ and Gradle 4.10+ for the JavaFX-based wallettemplate
• Gradle - 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 Gradle 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

Official builds are currently using with JDK 8, even though the core module is compatible with JDK 7 and later.

To perform a full build (including JavaDocs and unit/integration tests) use JDK 8+

gradle clean build

If you are running JDK 11 or later and Gradle 4.10 or later, the build will automatically include the JavaFX-based wallettemplate module. The outputs are under the build directory.

To perform a full build without unit/integration tests use:

gradle clean assemble

Building from an IDE

Alternatively, just import the project using your IDE. IntelliJ has Gradle integration built-in and has a free Community Edition. Simply use File | New | Project from Existing Sources and locate the build.gradle in the root of the cloned project source tree.

Building and Using the Wallet Tool

The bitcoinj tools subproject includes a command-line Wallet Tool (wallet-tool) that can be used to create and manage bitcoinj-based wallets (both the HD keychain and SPV blockchain state.) Using wallet-tool on Bitcoin's test net is a great way to learn about Bitcoin and bitcoinj.

To build an executable shell script that runs the command-line Wallet Tool, use:

gradle bitcoinj-tools:installDist

You can now run the wallet-tool without parameters to get help on its operation:

./tools/build/install/wallet-tool/bin/wallet-tool

To create a test net wallet file in ~/bitcoinj/bitcoinj-test.wallet, you would use:

mkdir ~/bitcoinj
./tools/build/install/wallet-tool/bin/wallet-tool --net=TEST --wallet=$HOME/bitcoinj/bitcoinj-test.wallet create

To sync the newly created wallet in ~/bitcoinj/bitcoinj-test.wallet with the test net, you would use:

./tools/build/install/wallet-tool/bin/wallet-tool --net=TEST --wallet=$HOME/bitcoinj/bitcoinj-test.wallet sync

To dump the state of the wallet in ~/bitcoinj/bitcoinj-test.wallet with the test net, you would use:

./tools/build/install/wallet-tool/bin/wallet-tool --net=TEST --wallet=$HOME/bitcoinj/bitcoinj-test.wallet dump

Note: These instructions are for macOS/Linux, for Windows use the tools/build/install/wallet-tool/bin/wallet-tool.bat batch file with the equivalent Windows command-line commands and options.

Example applications

These are found in the examples module.

Where next?

Now you are ready to follow the tutorial.

Contributing to bitcoinsvj

If you would like to help contribute to bitcoinsvj, feel free to make changes and submit pull requests.

Not a programmer? Not a problem. You can donate Bitcoin to the addresses below: