EtherJar

Framework agnostic modular Java 17+ integration library for Ethereum blockchains

• Latest Stable Version: 0.12.0
• Latest Snapshot Version: 0.13.0-SNAPSHOT

Modules

Structure of dependencies between modules:

• etherjar-abi
  • etherjar-domain
  • etherjar-hex
• etherjar-domain
• etherjar-hex
• etherjar-rlp
• etherjar-rpc-json
  • etherjar-domain
  • etherjar-hex
• etherjar-rpc-api
  • etherjar-rpc-json
  • etherjar-domain
  • etherjar-hex
• etherjar-rpc-emerald
  • etherjar-rpc-api
• etherjar-rpc-http
  • etherjar-rpc-api
  • etherjar-domain
  • etherjar-hex
• etherjar-rpc-ws
  • etherjar-rpc-api
• etherjar-solidity
  • etherjar-abi
  • etherjar-domain
• etherjar-tx
  • etherjar-rlp
  • etherjar-domain
• etherjar-contract
  • etherjar-abi
  • etherjar-domain
  • etherjar-rpc-api
• etherjar-erc20
  • etherjar-abi
  • etherjar-domain
  • etherjar-contract

where

• etherjar-abi - Smart contract Application Binary Interface (ABI)
• etherjar-contract - Methods to organize contract call
• etherjar-domain - Core module contains pure domain logic (Address, Block, Transaction , Wei and so on)
• etherjar-erc20 - Classes to simplify use of ERC-20 tokens
• etherjar-hex - Hexadecimal encoding and encoding utils for String, BigInteger, byte arrays
• etherjar-rlp - Reading and writing RLP (Recursive Length Prefix) encoded data
• etherjar-rpc-json - JSON mapping to/from Java objects
• etherjar-rpc-api - JSON-RPC API generic implementation
• etherjar-rpc-emerald - gRPC transport, see Emerald Dshackle
• etherjar-rpc-http - HTTP transport implementation for JSON-RPC API data-layer
• etherjar-rpc-ws - WebSocket transport to subscribe to new blocks
• etherjar-solidity - Thin wrapper around solc Solidity compiler
• etherjar-tx - Read, verify and manipulate Transactions

Usage

Maven

<repositories>
    <repository>
      <id>etherjar</id>
      <url>https://maven.emrld.io</url>
    </repository>
</repositories>

<dependency>
  <groupId>io.emeraldpay.etherjar</groupId>
  <artifactId>etherjar-rpc-http</artifactId>
  <version>0.12.0</version>
</dependency>

Gradle

repositories {
  maven {
    url "https://maven.emrld.io"
  }
}

dependencies {
    implementation "io.emeraldpay.etherjar:etherjar-rpc-http:0.12.0"
}

Examples

How to call web3_clientVersion low-level JSON-RPC API method:

public class GetClientVersion {
    public static void main(String[] args)
            throws URISyntaxException, IOException, ExecutionException, InterruptedException {        
        try (RpcTransport transport = HttpRpcTransport.newBuilder().connectTo("http://127.0.0.1:8545").build()) {
            RpcClient client = new DefaultRpcClient(transport);
            Future<String> req = client.execute(Commands.web3().clientVersion());

            System.out.println(String.format("Client version: %s", req.get()));
        }
    }
}

How to call eth_gasPrice low-level JSON-RPC API method:

public class GetGasPrice {

    public static void main(String[] args)
            throws URISyntaxException, IOException, ExecutionException, InterruptedException {

        try (RpcTransport transport = HttpRpcTransport.newBuilder().connectTo("http://127.0.0.1:8545").build()) {
            RpcClient client = new DefaultRpcClient(transport);
            Future<Wei> req = client.execute(Commands.eth().getGasPrice());

            System.out.println(String.format("Gas Price: %s Ether", req.get().toEthers(12)));
        }
    }
}

Documentation

• Reference Guide

Bugs and Feedback

For bugs, questions and discussions please use the GitHub Issues.

Licence

Copyright 2021 EmeraldPay, Inc

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.