依赖

<dependency>
    <groupId>org.web3j</groupId>
    <artifactId>core</artifactId>
    <version>3.2.0</version>
</dependency>


<dependency>
    <groupId>org.bitcoinj</groupId>
    <artifactId>bitcoinj-core</artifactId>
    <version>0.16.2</version>
</dependency>

import org.bitcoinj.core.*;
import org.bitcoinj.crypto.MnemonicCode;
import org.bitcoinj.params.TestNet3Params;
import org.bitcoinj.wallet.DeterministicSeed;
import org.bitcoinj.wallet.Wallet;

public class BitcoinJDemo {

    public static void main(String[] args) throws Exception {
        // 设置网络参数为测试网络
        NetworkParameters params = TestNet3Params.get();
        // 助记词
        String mnemonic = "pistol maple duty lunch canyon critic oil party age brother join pulp";
        // 将助记词转换为种子
        DeterministicSeed seed = new DeterministicSeed(mnemonic, null, "", 0);
        // 从种子生成钱包对象
        Wallet wallet = Wallet.fromSeed(params, seed);
        // 获取当前接收地址对应的公钥和私钥
        ECKeyPair keyPair = wallet.currentReceiveKey();
        System.out.println("公钥：" + keyPair.getPublicKey().toString());
        System.out.println("私钥：" + keyPair.getPrivateKeyAsHex());
    }
}