前言
在做离线钱包的过程中，波场是有资料，但是资料最坑的一个币，不过还有最终顺利完成开发。
资料
https://www.jianshu.com/p/275036a09be3 里面是别人收集的TRX相关信息。
官方Demo
https://github.com/tronprotocol/wallet-cli/blob/master/src/main/java/org/tron/demo/TransactionSignDemo.java
说明
因为我们是离线钱包，一次我们没用RPC的方式去获取块信息，是现在业务端获取到节点信息，在到离线的环境签名，再去广播。如果用本地节点或者超级节点RPC的方式的话，就用官方demo就好了。不过我们直接是用的api接口获取的数据，所有出来了一些问题。
首先构建https://github.com/tronprotocol/wallet-cli项目，成功后拿到/build/libs/wallet-1.0-SNAPSHOT.jar，然后就开启你的代码之旅吧。
源码
import com.alibaba.fastjson.JSON;
import com.google.protobuf.Any;
import com.google.protobuf.ByteString;
import com.google.protobuf.InvalidProtocolBufferException;
import java.util.Map;
import org.bouncycastle.util.encoders.Hex;
import org.tron.common.crypto.ECKey;
import org.tron.common.crypto.Sha256Hash;
import org.tron.common.utils.ByteArray;
import org.tron.core.exception.CancelException;
import org.tron.protos.Contract;
import org.tron.protos.Protocol.Block;
import org.tron.protos.Protocol.Transaction;
import org.tron.walletserver.WalletApi;
public class TransactionSignDemo {
public static Transaction createTransaction(byte[] from, byte[] to, long amount,long blockTimestamp,long blockHeight,byte[] blockHash) {
Transaction.Builder transactionBuilder = Transaction.newBuilder();
//Block newestBlock = WalletApi.getBlock(-1);
Transaction.Contract.Builder contractBuilder = Transaction.Contract.newBuilder();
Contract.TransferContract.Builder transferContractBuilder = Contract.TransferContract.newBuilder();
transferContractBuilder.setAmount(amount);
ByteString bsTo = ByteString.copyFrom(to);
ByteString bsOwner = ByteString.copyFrom(from);
transferContractBuilder.setToAddress(bsTo);
transferContractBuilder.setOwnerAddress(bsOwner);
try {
Any any = Any.pack(transferContractBuilder.build());
contractBuilder.setParameter(any);
} catch (Exception e) {
return null;
}
contractBuilder.setType(Transaction.Contract.ContractType.TransferContract);
transactionBuilder.getRawDataBuilder().addContract(contractBuilder).setTimestamp(System.currentTimeMillis())
.setExpiration(blockTimestamp + 10 * 60 * 60 * 1000);
Transaction transaction = transactionBuilder.build();
Transaction refTransaction = setReference(transaction, blockHeight,blockHash);
return refTransaction;
}
public static Transaction setReference(Transaction transaction, long blockHeight,byte[] blockHash) {
//long blockHeight = newestBlock.getBlockHeader().getRawData().getNumber();
//byte[] blockHash = getBlockHash(newestBlock).getBytes();
byte[] refBlockNum = ByteArray.fromLong(blockHeight);
Transaction.raw rawData = transaction.getRawData().toBuilder()
.setRefBlockHash(ByteString.copyFrom(ByteArray.subArray(blockHash, 8, 16)))
.setRefBlockBytes(ByteString.copyFrom(ByteArray.subArray(refBlockNum, 6, 8))).build();
return transaction.toBuilder().setRawData(rawData).build();
}
public static Sha256Hash getBlockHash(Block block) {
return Sha256Hash.of(block.getBlockHeader().getRawData().toByteArray());
}
public static String getTransactionHash(Transaction transaction) {
String txid = ByteArray.toHexString(Sha256Hash.hash(transaction.getRawData().toByteArray()));
return txid;
}
private static byte[] signTransaction2Byte(byte[] transaction, byte[] privateKey)
throws InvalidProtocolBufferException {
ECKey ecKey = ECKey.fromPrivate(privateKey);
Transaction transaction1 = Transaction.parseFrom(transaction);
byte[] rawdata = transaction1.getRawData().toByteArray();
byte[] hash = Sha256Hash.hash(rawdata);
byte[] sign = ecKey.sign(hash).toByteArray();
return transaction1.toBuilder().addSignature(ByteString.copyFrom(sign)).build().toByteArray();
}
public static void main(String[] args) throws InvalidProtocolBufferException, CancelException {
String privateStr = "你的私钥";
byte[] privateBytes = ByteArray.fromHexString(privateStr);
ECKey ecKey = ECKey.fromPrivate(privateBytes);
byte[] from = ecKey.getAddress();
byte[] to = WalletApi.decodeFromBase58Check("地址");
long amount = 100_000_000L;
String blockStr = HttpUtil.get("https://apilist.tronscan.org/api/block/latest");
Map blockInfo=JSON.parseObject(blockStr);
System.out.println(blockInfo.toString());
Long blockTimestamp = Long.parseLong(blockInfo.get("timestamp").toString());
Long blockHeight = Long.parseLong(blockInfo.get("number").toString());
byte[] blockHash = Hex.decode(blockInfo.get("hash").toString());
//开始看官方demo改写的blockHashd，但是错的，签名没的问题，但是广播就报错TAPOS_ERROR，说块不在链上。
byte[] blockHash2=Sha256Hash.of(blockInfo.get("hash").toString().getBytes()).getBytes();
System.out.println("===blockHash:"+ByteArray.toHexString(blockHash));
System.out.println("===blockHash2:"+ByteArray.toHexString(blockHash2));
Transaction transaction = createTransaction(from, to, amount, blockTimestamp, blockHeight, blockHash);
byte[] transactionBytes = transaction.toByteArray();
byte[] transaction4 = signTransaction2Byte(transactionBytes, privateBytes);
System.out.println("transaction4 ::::: " + ByteArray.toHexString(transaction4));
//广播的URL:https://apilist.tronscan.org/api/broadcast
}
} 以上就是我们签名的demo了，和原来的改变不大，但是却一度致命，开始的时候一直广播报错：TAPOS_ERROR，看了下这个错是块不在链上，但是我们set又get出来，都是正确的块hash值。而源码中有没的Block的源码，所以一度不知道怎么解决。还好后面发现Hex.decode(）方法转的byte的后与打印交易的Transaction.toString()方法内容一样，于是广播，结果成功了。
这个只是一个demo，至于怎么获取私钥，怎么实现离线的，根据自己业务场景自己衡量哈。